CN118413730B - Aperture driving circuit and camera - Google Patents
Aperture driving circuit and camera Download PDFInfo
- Publication number
- CN118413730B CN118413730B CN202410867712.7A CN202410867712A CN118413730B CN 118413730 B CN118413730 B CN 118413730B CN 202410867712 A CN202410867712 A CN 202410867712A CN 118413730 B CN118413730 B CN 118413730B
- Authority
- CN
- China
- Prior art keywords
- voltage
- resistor
- aperture
- capacitor
- driving
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 71
- 230000010354 integration Effects 0.000 claims abstract description 12
- 230000003321 amplification Effects 0.000 claims abstract description 11
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 11
- 238000013016 damping Methods 0.000 claims description 59
- 230000005291 magnetic effect Effects 0.000 claims description 33
- 230000009471 action Effects 0.000 claims description 14
- 238000007493 shaping process Methods 0.000 claims description 13
- 230000005294 ferromagnetic effect Effects 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 22
- 238000010586 diagram Methods 0.000 description 21
- 229910052742 iron Inorganic materials 0.000 description 11
- 238000000034 method Methods 0.000 description 8
- 230000008859 change Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 230000009125 negative feedback regulation Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/50—Constructional details
- H04N23/54—Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/50—Constructional details
- H04N23/55—Optical parts specially adapted for electronic image sensors; Mounting thereof
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/69—Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Diaphragms For Cameras (AREA)
Abstract
The embodiment of the application provides an aperture driving circuit and a camera, wherein the aperture driving circuit comprises a voltage superposition operation module and an integration amplification module; the voltage superposition operation module comprises: the first resistor, the second resistor, the third resistor, the fourth resistor and the first capacitor; the first end of the first resistor is used for being connected with the second voltage end, the second end of the first resistor is connected with the first end of the second resistor, the first end of the third resistor and the first end of the first capacitor, and the second end of the first capacitor is grounded; the second end of the second resistor is connected with the non-inverting input end of the integrating amplifying module, the negative feedback voltage end of the aperture and the first voltage end; the second end of the third resistor is connected with the first end of the fourth resistor and the inverting input end of the integrating amplifying module, and the second end of the fourth resistor is connected with the positive feedback voltage end of the aperture; the output end of the integration amplifying module is connected with the driving voltage input end of the aperture. The circuit structure is simplified, and the production cost of the driving circuit with the automatic aperture function is reduced.
Description
Technical Field
The application relates to the field of automatic aperture driving circuits of cameras, in particular to an aperture driving circuit and a camera.
Background
In the prior art, an automatic aperture of a zoom lens of a camera integrates a zoom focusing function, and the automatic aperture device comprises a driving coil and a Hall sensor. As shown in fig. 1, the processor drives an integrated driving microcircuit through an SPI (SERIAL PERIPHERAL INTERFACE ) signal, and the integrated driving microcircuit outputs a first signal and a second signal; as shown in fig. 2, the first signal drives the driving coil of the automatic aperture to adjust the aperture, and after the aperture acts, the position of the hall sensor sensing the aperture acts is fed back to the integrated driving microcircuit through the automatic aperture feedback signal to realize closed-loop control; the second signal drives the zoom focusing motor, and the internal photodiode generates a position feedback signal after the motor acts, and the position feedback signal is fed back to the processor so as to acquire the position of the mechanical end driven by the motor.
With the popularity and development of video cameras, many indoor scenes no longer require a zoom lens, but an automatic aperture function is still required in order to accommodate illumination changes. In the related art, only the zoom focus motor in the camera is removed in order to save costs in the face of a scene where the zoom lens is no longer required, but an integrated driving micro circuit is still used in order to realize an automatic aperture function. Although the use of the integrated driving microcircuit can meet the requirement of the automatic aperture function, the driving function of the zoom focusing is wasted, and the cost of the integrated driving microcircuit is high, resulting in high cost of the camera with the automatic aperture function.
Disclosure of Invention
An object of an embodiment of the present application is to provide an aperture driving circuit and a camera, so as to reduce the production cost of the camera with an automatic aperture function. The specific technical scheme is as follows:
the embodiment of the application provides an aperture driving circuit, which comprises:
The voltage superposition operation module and the integration amplification module;
The voltage superposition operation module comprises: the first resistor, the second resistor, the third resistor, the fourth resistor and the first capacitor;
The first end of the first resistor is used for being connected with a second voltage end, the second end of the first resistor is connected with the first end of the second resistor, the first end of the third resistor and the first end of the first capacitor, and the second end of the first capacitor is grounded; the second voltage end is used for being connected with a Pulse Width Modulation (PWM) signal;
The second end of the second resistor is connected with the non-inverting input end of the integrating amplifying module, and the second end of the second resistor is also used for connecting a negative feedback voltage end and a first voltage end of the aperture; the first voltage end is used for accessing a voltage signal with a preset amplitude;
the second end of the third resistor is connected with the first end of the fourth resistor and the inverting input end of the integrating amplifying module, and the second end of the fourth resistor is used for being connected with the positive feedback voltage end of the aperture;
the output end of the integration amplifying module is used for being connected with the driving voltage input end of the aperture.
In one possible embodiment, the aperture driving circuit further includes: the reference partial pressure following module and the signal shaping module;
The reference voltage division following module is used for outputting the voltage signal with the preset amplitude value to the first voltage end;
The signal shaping module is used for responding to the control of the processor and outputting PWM signals with specified duty ratio to the second voltage terminal.
In one possible implementation, the integrating amplifying module includes:
A first operational amplifier, a second capacitor, a third capacitor, a fifth resistor:
The first operational amplifier non-inverting input end is connected with the second end of the second resistor, and the first operational amplifier inverting input end is connected with the first end of the second capacitor, the first end of the third capacitor and the second end of the third resistor;
the high-voltage input end of the first operational amplifier is used for being connected with a first power supply, and the low-voltage input end of the first operational amplifier is grounded;
The output end of the first operational amplifier is connected with the second end of the second capacitor and the second end of the fifth resistor, and the output end of the first operational amplifier is also used for being connected with the driving voltage input end of the aperture;
The second end of the third capacitor is connected with the first end of the fifth resistor.
In one possible embodiment, the reference partial pressure following module includes:
A second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, and a sixth capacitor:
the non-inverting input end of the second operational amplifier is connected with the first end of the sixth resistor, the first end of the fourth capacitor and the first end of the seventh resistor, and the inverting input end of the second operational amplifier is connected with the first end of the eighth resistor and the first end of the sixth capacitor;
The high-voltage input end of the second operational amplifier is connected with the second end of the sixth resistor and the first end of the fifth capacitor, and the high-voltage input end of the second operational amplifier is also used for being connected with a first power supply;
The output end of the second operational amplifier is connected with the second end of the eighth resistor and the second end of the sixth capacitor, and the output end of the second operational amplifier is also used for being connected with the first voltage end;
The low voltage input end of the second operational amplifier, the second end of the fourth capacitor, the second end of the seventh resistor and the second end of the fifth capacitor are grounded.
In one possible implementation, the signal shaping module includes: third operational amplifier, ninth resistor:
the non-inverting input end of the third operational amplifier is used for being connected with an input voltage signal end of the processor, the inverting input end of the third operational amplifier is connected with the first end of the ninth resistor, the output end of the third operational amplifier and the second voltage end, the high voltage input end of the third operational amplifier is used for being connected with a first power supply, and the second end of the ninth resistor and the low voltage input end of the third operational amplifier are grounded.
The embodiment of the application also provides a camera, which comprises: a processor, an aperture, and an aperture driving circuit according to any one of the present application;
The processor is used for determining a target duty ratio corresponding to the target opening degree of the aperture and sending a PWM signal of the target duty ratio to the aperture driving circuit;
The diaphragm driving circuit is used for responding to the PWM signal of the target duty ratio and sending a driving voltage signal to the driving voltage input end of the diaphragm;
The aperture is used for responding to the driving voltage signal and opening to the target opening degree.
In one possible embodiment, the aperture comprises a driving coil, a damping coil;
the driving voltage input end of the driving coil is connected with the output end of the integrating amplifying module, the negative feedback voltage end of the damping coil is connected with the first voltage end, and the positive feedback voltage end of the damping coil is connected with the second end of the fourth resistor;
the driving coil is used for generating a driving magnetic field under the driving of the aperture driving circuit;
The damping coil is used for generating a damping magnetic field under the action of the driving coil and feeding back induced voltage to the aperture driving circuit through the positive feedback voltage end and the negative feedback voltage end.
In one possible embodiment, the drive coil is wound side by side or overlapping the damping coil.
In one possible embodiment, the aperture further comprises: the magnetic core rotor, the aperture deflector rod, the aperture blade and the ferromagnetic metal;
The ferromagnetic metal is arranged outside the driving coil and the damping coil, the magnetic core rotor is positioned inside the driving coil and the damping coil, the aperture deflector rod is arranged on the magnetic core rotor, and the aperture deflector rod rotates along with the rotation of the magnetic core rotor; the end part of the aperture deflector rod is directly or indirectly contacted with the aperture blade, and the rotation of the aperture deflector rod drives the aperture blade to be opened or closed.
In one possible embodiment, the attractive force between the core rotor and the ferromagnetic metal is of the order of an exponential multiple of the aperture blade resistance, wherein the aperture blade resistance includes the friction force and the electrostatic attractive force of the aperture blade.
The embodiment of the application has the beneficial effects that:
The embodiment of the application provides an aperture driving circuit, which comprises: the voltage superposition operation module and the integration amplification module; the voltage superposition operation module comprises: the first resistor, the second resistor, the third resistor, the fourth resistor and the first capacitor; the first end of the first resistor is used for being connected with the second voltage end, the second end of the first resistor is connected with the first end of the second resistor, the first end of the third resistor and the first end of the first capacitor, and the second end of the first capacitor is grounded; the second voltage end is used for being connected with a Pulse Width Modulation (PWM) signal; the second end of the second resistor is connected with the non-inverting input end of the integrating amplifying module, and the second end of the second resistor is also used for connecting the negative feedback voltage end and the first voltage end of the aperture; the first voltage end is used for accessing a voltage signal with a preset amplitude; the second end of the third resistor is connected with the first end of the fourth resistor and the inverting input end of the integrating amplifying module, and the second end of the fourth resistor is used for being connected with the positive feedback voltage end of the aperture; the output end of the integration amplifying module is used for being connected with the driving voltage input end of the aperture. The feedback voltage of the automatic aperture and the voltages of the first voltage end and the second voltage end are superposed and input into the voltage superposition operation module, so that the output voltage of the integration amplification module is regulated, the circuit structure is simplified, and the production cost of the driving circuit with the automatic aperture function is reduced.
Of course, it is not necessary for any one product or method of practicing the application to achieve all of the advantages set forth above at the same time.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the application, and other embodiments may be obtained according to these drawings to those skilled in the art.
FIG. 1 is a first schematic diagram of an automatic aperture driving circuit in the related art;
FIG. 2 is a second schematic diagram of an automatic aperture driving circuit according to the related art;
FIG. 3 is a first schematic diagram of an aperture driving circuit according to an embodiment of the application;
FIG. 4 is a second schematic diagram of an aperture driving circuit according to an embodiment of the application;
FIG. 5 is a third schematic diagram of an aperture driving circuit according to an embodiment of the application;
FIG. 6 is a schematic diagram of a portion of an aperture driving circuit according to an embodiment of the application;
FIG. 7 is a schematic diagram of an integrating amplifying module in an aperture driving circuit according to an embodiment of the present application;
FIG. 8 is a schematic diagram of a reference partial pressure follower module in an aperture driving circuit according to an embodiment of the application;
FIG. 9 is a schematic diagram of a signal shaping module in an aperture driving circuit according to an embodiment of the application;
FIG. 10 is a first schematic view of a camera according to an embodiment of the present application;
FIG. 11 is a second schematic view of a camera according to an embodiment of the present application;
FIG. 12 is a first equivalent circuit diagram of an aperture driving circuit according to an embodiment of the present application;
FIG. 13 is a graph showing the linear relationship between the duty cycle of the aperture driving circuit and the output voltage of the voltage superposition module according to the embodiment of the present application;
FIG. 14 is a second equivalent circuit diagram of the aperture driving circuit according to the embodiment of the present application;
FIG. 15 is a first schematic view of an aperture in a camera according to an embodiment of the present application;
FIG. 16 is a second schematic view of an aperture in a camera according to an embodiment of the present application;
FIG. 17 (a) is a force diagram of an aperture in a camera in an initial position according to an embodiment of the present application;
FIG. 17 (b) is a diagram showing the force applied to the aperture in the middle position of the camera according to the embodiment of the present application;
Fig. 17 (c) is a force diagram of the aperture in the fully open position in the camera according to the embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by the person skilled in the art based on the present application are included in the scope of protection of the present application.
In recent years, the development of the camera industry is mature, and the competition pressure is also high. The existing cameras with automatic aperture function are integrated with zoom focusing function, the automatic aperture driving circuit in the related art is seen in fig. 1, the zoom lens comprises an automatic aperture and a lens zoom focusing motor, the processor drives the integrated driving microcircuit through SPI signals, the integrated driving microcircuit generates two output signals, the first signal drives the automatic coil to act, and the second signal drives the lens zoom focusing motor to realize the zoom focusing function.
The automatic aperture inside the zoom lens comprises a driving coil and a Hall sensor, and referring to FIG. 2, the driving coil of the automatic aperture generates a first signal through an integrated driving micro circuit to drive the aperture to complete the action; the Hall sensor detects the position of the aperture action, generates an automatic aperture feedback signal and feeds the automatic aperture feedback signal back to the integrated driving microcircuit to realize closed-loop control; the integrated driving micro-circuit generates a second signal to drive the zoom focusing motor, the zoom focusing motor acts to realize the zoom focusing function, a photodiode (not shown in the figure) in the zoom focusing motor generates a position feedback signal to be fed back to the processor, and the processor obtains the position of a mechanical end of the motor driving through the position feedback signal.
With the popularity and development of video cameras, many indoor scenes no longer require a zoom lens, but an automatic aperture function is still required in order to accommodate illumination changes. In the related art, only the zoom focus motor in the camera is removed in order to save costs in the face of a scene where the zoom lens is no longer required, but an integrated driving micro circuit is still used in order to realize an automatic aperture function. Although the use of the integrated driving microcircuit can meet the requirement of the automatic aperture function, the driving function of the zoom focusing is wasted, and the cost of the integrated driving microcircuit is high, resulting in high cost of the camera with the automatic aperture function.
In order to realize the manufacture of an automatic aperture driving circuit by using discrete components, simplify the circuit structure and reduce the production cost of the driving circuit with only an automatic aperture function, the embodiment of the application provides an aperture driving circuit and a camera, and the following detailed description is given:
Referring to fig. 3, fig. 3 is a first schematic diagram of an aperture driving circuit according to an embodiment of the present application, since the aperture driving circuit uses discrete components instead of an integrated driving micro circuit, the processor does not need to output an SPI signal, only needs to output a PWM (Pulse width modulation ) signal, and thus the SPI bandwidth of the processor is saved; the Hall sensor is removed from the inside of the aperture, a damping coil is added, and after receiving the PWM signal output by the processor, the aperture driving circuit generates an aperture driving signal to drive the aperture to act, and after the aperture acts, the damping coil outputs a damping signal to be fed back to the aperture driving circuit. The mechanical structure of the automatic aperture in the embodiment of the application is a double-coil blade structure, the aperture can be opened and closed by driving the coil, and the processor adjusts PWM signals by inputting different duty ratios, so that different driving voltages are output, and the size of the aperture is adjusted.
An embodiment of the present application provides an aperture driving circuit, referring to fig. 4, including:
a voltage superposition operation module 103, an integration amplification module 104;
The voltage superposition operation module 103 includes: the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the first capacitor C1;
The first end of the first resistor R1 is used for being connected with a second voltage end U2, the second end of the first resistor R1 is connected with the first end of the second resistor R2, the first end of the third resistor R3 and the first end of the first capacitor C1, and the second end of the first capacitor C1 is grounded; the second voltage end U2 is used for accessing PWM signals;
The second end of the second resistor R2 is connected to the non-inverting input terminal 1041 of the integrating amplifying module 104, and the second end of the second resistor R2 is further used for connecting the negative feedback voltage end and the first voltage end U1 of the aperture 105; the first voltage end U1 is used for accessing a voltage signal with a preset amplitude;
The second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the inverting input terminal 1042 of the integrating amplifying module 104, and the second end of the fourth resistor R4 is used for connecting the positive feedback voltage end of the aperture 105;
the output 1044 of the integrating amplifier module 104 is used to connect to the driving voltage input 1051 of the aperture.
The voltage signals of the first voltage terminal U1 and the second voltage terminal U2 are input into a voltage superposition operation module 103, the voltage superposition operation module 103 inputs the processed voltage signals into an integral amplification module 104, the integral amplification module 104 outputs aperture driving voltage signals to drive a driving coil of an aperture to act, and the aperture opening and closing size is changed by controlling the driving voltage of the coil, as shown in fig. 5; after the aperture acts, the damping coil of the aperture generates a pair of differential feedback voltages, the negative feedback voltage signal output by the negative feedback signal end is overlapped with the voltage signal of U1, the positive feedback voltage signal output by the positive feedback signal end is overlapped with the voltage signal of U2, and the input voltage of the voltage overlapping operation module 103 is changed, so that a new aperture driving voltage is generated. The feedback circuit is used for carrying out negative feedback adjustment on the diaphragm driving voltage, so that the automatic diaphragm action is more stable, and the diaphragm operation is more stable.
In one possible embodiment, referring to fig. 6, the aperture driving circuit further includes: a reference voltage division following module 101 and a signal shaping module 102;
The reference voltage division following module 101 is configured to output the voltage signal with the preset amplitude to the first voltage terminal U1;
the signal shaping module 102 is configured to output a PWM signal with a specified duty cycle to the second voltage terminal U2 in response to control of the processor.
The voltage output by the reference voltage division following module 101 and the voltage output by the signal shaping module 102 are input into the voltage superposition operation module 103 through the first voltage end U1 and the second voltage end U2, and compared with single-ended input voltage, the double-ended input voltage has smaller error and more stable circuit operation.
In one possible implementation, referring to fig. 7, the integrating amplifying module 104 includes:
The first operational amplifier UD1, the second capacitor C2, the third capacitor C3, and the fifth resistor R5:
the non-inverting input terminal 1041 of the first operational amplifier UD1 is connected to the second terminal of the second resistor R2, and the inverting input terminal 1042 of the first operational amplifier UD1 is connected to the first terminal of the second capacitor C2, the first terminal of the third capacitor C3, and the second terminal of the third resistor R3;
The high voltage input end 1045 of the first operational amplifier UD1 is used for connecting to a first power supply Vref, and the low voltage input end 1043 of the first operational amplifier UD1 is grounded;
The output terminal 1044 of the first operational amplifier UD1 is connected to the second terminal of the second capacitor C2 and the second terminal of the fifth resistor R5, and the output terminal 1044 of the first operational amplifier UD1 is further configured to be connected to the driving voltage input terminal 1051 of the diaphragm 105;
The second end of the third capacitor C3 is connected to the first end of the fifth resistor R5.
The voltage superposition operation module 103 inputs the processed voltage signal into the integration and amplification module 104, and the integration and amplification module 104 outputs an aperture driving voltage signal to drive a driving coil of an aperture to act.
In one possible implementation, referring to fig. 8, the reference partial pressure following module 101 includes:
The second operational amplifier UD2, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6:
the non-inverting input terminal 1011 of the second operational amplifier UD2 is connected to the first terminal of the sixth resistor R6, the first terminal of the fourth capacitor C4, and the first terminal of the seventh resistor R7, and the inverting input terminal 1012 of the second operational amplifier UD2 is connected to the first terminal of the eighth resistor R8 and the first terminal of the sixth capacitor C6;
The high voltage input 1015 of the second operational amplifier UD2 is connected to the second end of the sixth resistor R6 and the first end of the fifth capacitor C5, and the high voltage input 1015 of the second operational amplifier UD2 is further connected to the first power supply Vref;
The output end 1014 of the second operational amplifier UD2 is connected to the second end of the eighth resistor R8 and the second end of the sixth capacitor C6, and the output end 1014 of the second operational amplifier UD2 is further configured to connect to the first voltage end U1;
The low voltage input 1013 of the second operational amplifier UD2, the second end of the fourth capacitor C4, the second end of the seventh resistor R7, and the second end of the fifth capacitor C5 are grounded.
The reference voltage division follower module 101 inputs a voltage signal by the first power supply Vref, the fourth capacitor C4 and the sixth capacitor C6 perform filtering, the eighth resistor R8 and the fifth capacitor C5 generate a cut-off frequency of the second operational amplifier UD2, the second operational amplifier UD2 is used as a follower, the output voltage u1=r6xvref/(r6+r7) of the reference voltage division follower module 101, where each symbol in the formula represents a value of a resistor or a voltage corresponding to the symbol, where Vref represents a voltage value of the first power supply Vref, R6 is a resistance value of the sixth resistor R6, R7 is a resistance value of the seventh resistor R7, and U1 is a voltage amplitude of the first voltage end U1, that is, an output voltage of the reference voltage division follower module 101.
In one possible implementation, referring to fig. 9, the signal shaping module 102 includes: third operational amplifier UD3, ninth resistor R9:
The non-inverting input 1021 of the third operational amplifier UD3 is configured to be connected to an input voltage signal of the processor, the inverting input 1022 of the third operational amplifier UD3 is connected to the first end of the ninth resistor R9, the output 1024 of the third operational amplifier UD3, and the second voltage end U2, the high voltage input 1025 of the third operational amplifier UD3 is configured to be connected to the first power supply Vref, and the second end of the ninth resistor R9 and the low voltage input 1023 of the third operational amplifier UD3 are grounded.
The processor outputs PWM pulse signals, the voltage characteristics are unchanged after the following of the third operational amplifier UD3, the waveform is still a pulse waveform, the following amplifier can reduce signal loss generated by higher output impedance and lower next-stage impedance, the buffer effect of signal transmission is achieved, meanwhile, signal noise is reduced, and the current output capacity is improved.
The embodiment of the application also provides a camera, referring to fig. 10, including: a processor, a diaphragm 105, and a diaphragm driving circuit according to any one of the present application;
The processor is used for determining a target duty ratio corresponding to the target opening degree of the aperture and sending a PWM signal of the target duty ratio to the aperture driving circuit;
The aperture driving circuit is configured to send a driving voltage signal to a driving voltage input terminal 1051 of the aperture 105 in response to the PWM signal of the target duty ratio;
the diaphragm 105 is configured to open to the target opening degree in response to the driving voltage signal.
Compared with the processor in the related art, the processor outputs the PWM pulse signal with the duty ratio of D, and the requirements on the processor are lower, so that the circuit production cost is reduced.
In one possible embodiment, see fig. 11, the aperture comprises a driving coil, a damping coil;
The driving voltage input end 1051 of the driving coil is connected with the output end 1044 of the integrating amplifying module 104, the negative feedback voltage end of the damping coil is connected with the first voltage end U1, and the positive feedback voltage end of the damping coil is connected with the second end of the fourth resistor R4;
the driving coil is used for generating a driving magnetic field under the driving of the aperture driving circuit;
The damping coil is used for generating a damping magnetic field under the action of the driving coil and feeding back induced voltage to the aperture driving circuit through the positive feedback voltage end and the negative feedback voltage end.
Referring to fig. 12, the damping coil of the diaphragm in fig. 12 is equivalent to an ideal voltage source Uc and a resistor Rc, the voltage value of the damping coil equivalent voltage Uc is equal to the induced voltage of the damping coil, the resistance value of the damping coil equivalent resistor Rc is equal to the internal resistance value of the damping coil, ucon+ is the positive feedback voltage of the damping coil of the automatic diaphragm, ucon is the negative feedback voltage of the damping coil of the automatic diaphragm, and U3 is the output voltage of the second output terminal of the voltage superposition operation module 103.
When the aperture is static, no induced voltage exists in the damping coil, and the equivalent voltage Uc of the damping coil is=0; u2 is the pulse voltage output by the signal shaping module 102, and is also the voltage of the second voltage end U2, U2 is cut off by a low-pass filter formed by the first resistor R1 and the first capacitor C1, and is converted into voltage VrefxD (D is duty ratio, vref is the voltage amplitude of the first power supply), and after calculation according to the voltage superposition principle, the output voltage U3 of the second output end of the voltage superposition operation module 103 is:
U3=++ ；
Each symbol in the formula represents the resistance and voltage values of the corresponding symbol, wherein R1 is the resistance of the first resistor R1, R3 is the resistance of the third resistor R3, R4 is the resistance of the fourth resistor R4, rc is the resistance of the equivalent resistance Rc of the damping coil, R1, R3, R4, rc are known numbers, the amplitude of the output voltage U1 of the reference voltage division follower module 101 is a known number, the amplitude u2= VrefxD of the pulse voltage U2 output by the signal shaping module 102, the formula of the output voltage U3 of the second output end of the voltage superposition operation module 103 can be simplified to u3=u0+kxd (U0, K are constants determined by the above formula, u0=0 = + ，D is a duty cycle), since the processor input voltage value and the duty cycle D are in a linear relationship, the output voltage U3 at the second output terminal of the voltage superposition operation module 103 and the processor input voltage are in a linear relationship, and a line diagram of the output voltage U3 at the second output terminal of the voltage superposition operation module 103 and the duty cycle D is shown in fig. 13.
If the duty ratio d=d0 (D0 is the duty ratio when u3=u11 is set, U11 is the first output voltage of the voltage superposition operation module 103), at this time, u3=u11, the first operational amplifier UD1 is virtually short, the second capacitor C2 starts to charge, and the diaphragm driving voltage Udrv starts to be generated.
When the diaphragm driving voltage Udrv is smaller than the action voltage of the diaphragm, the damping coil equivalent voltage uc=0, the first operational amplifier UD1 is still virtually short, the second capacitor C2 is continuously charged, and the equivalent circuit diagram of the diaphragm driving circuit is shown in fig. 14, and since the damping coil equivalent voltage uc=0, the current ic=0 of the damping coil equivalent resistance Rc (Ic is the current in the damping coil), the kirchhoff current theorem can obtain: (U4 is the voltage across the first capacitor C1 in the equivalent circuit shown in FIG. 14), the charging current of the integrating circuit It can be seen that the charging current of the integrating circuitThe aperture driving voltage is constant, i.e. the charging current is constant:
;
Each symbol in the formula represents the value of the resistance, voltage, capacitance, and current of the corresponding symbol, t is a time constant, wherein "UDRV +" is the starting voltage of the aperture driving voltage Udrv, and the output aperture driving voltage Udrv can be calculated by the formula.
When the diaphragm driving voltage Udrv reaches the action voltage of the diaphragm, the damping coil of the automatic diaphragm generates an induced voltage, namely the equivalent voltage Uc of the damping coil, and a part of current flows through the damping coil, the charging current of the second capacitor C2 decreases, and the change speed of the initial voltage UDRV + of the diaphragm driving voltage Udrv decreases. The calculation can be obtained by:
induced current generated by the damping coil The diaphragm driving voltage is:;
The symbols in the formula represent the values of resistance, voltage, capacitance and current of the corresponding symbols, t is a time constant, wherein 'UDRV +' is the initial voltage of the aperture driving voltage Udrv in the switching state from rest to operation, and the output aperture driving voltage Udrv can be calculated by the formula.
The driving voltage output by the aperture driving circuit under the negative feedback regulation action of the induced voltage is called a new driving voltage, and the slope of a voltage value broken line of the new driving voltage is called a first slope; the slope of the voltage value broken line of the driving voltage output by the diaphragm driving circuit is referred to as a second slope, assuming that there is no negative feedback adjustment effect of the induced voltage. The first slope is less than the second slope, which is referred to as negative feedback regulation. Through the negative feedback regulation, the change rate of the driving voltage can be reduced, so that the driving voltage change is stable, and the movement of the aperture blade is stable. The aperture driving circuit comprises a resistor and a capacitor, and the first slope is required to be in a preset slope interval, so that the adjustment rate of the aperture blade is finally smaller than a preset rate threshold value, and the adjustment rate of the aperture blade is controlled in a required range.
From the above function, it can be seen that when the aperture is opened, the induced current generated by the damping coilThe output diaphragm driving voltage Udrv is affected. In each driving cycle, a current is inducedAnd the driving voltage of the diaphragm is dynamically adjusted to enable the diaphragm to act and the circuit to run more stably.
Due to induced currentThe integral part value of the function is reduced, errors in the running process of the circuit are reduced, meanwhile, the speed of the change of the driving voltage is reduced, the change of the driving voltage is more stable, the action of the aperture blade is more stable, and mechanical abrasion of the aperture blade caused by too fast opening and closing is reduced.
In one possible embodiment, see fig. 15, the driving coil is wound side by side or overlapping the damping coil.
In one possible embodiment, see fig. 15-17 (c), the aperture further comprises: the magnetic core rotor, the aperture deflector rod, the aperture blade and the ferromagnetic metal; wherein, the ferromagnetic metal takes iron block as an example;
The ferromagnetic metal is arranged outside the driving coil and the damping coil, the magnetic core rotor is positioned inside the driving coil and the damping coil, the aperture deflector rod is arranged on the magnetic core rotor, and the aperture deflector rod rotates along with the rotation of the magnetic core rotor; the end part of the aperture deflector rod is directly or indirectly contacted with the aperture blade, and the rotation of the aperture deflector rod drives the aperture blade to be opened or closed.
The magnetic core rotor is a permanent magnet, and the driving coil and the damping coil outside the magnetic core form a stator. The mechanical structure of the automatic aperture is schematically shown in fig. 15, in which the driving coil and the damping coil are wound side by side or overlapped, and in fig. 16, for convenience of description, the driving coil and the damping coil are drawn to be concentric circles, and in fact, the driving coil and the damping coil have no similar inclusion relationship, and the electrodes on each coil after the S pole and the N pole are electrified to generate magnetic force. The aperture blades are two, and the opening and the closing of the two blades are controlled by the driving voltage of the driving coil so as to control the size of the aperture. The ferromagnetic metal may be iron, cobalt, nickel, gadolinium, etc., and in one example, the ferromagnetic metal may be iron block.
In one possible embodiment, the attractive force between the core rotor and the ferromagnetic metal is of the order of an exponential multiple of the aperture blade resistance, wherein the aperture blade resistance includes the friction force and the electrostatic attractive force of the aperture blade.
The stress conditions of the automatic aperture in each state are shown in fig. 17 (a) -17 (c), wherein fig. 17 (a) is a stress schematic diagram of an initial position of the aperture, fig. 17 (b) is a stress schematic diagram of the aperture opening to an intermediate position, and fig. 17 (c) is a stress schematic diagram of a complete opening position of the aperture, and an iron block generates an S pole and an N pole after being attracted by a magnet for a long time. The stress diagram only shows the stress direction, and the ray length does not represent the force.
F is the driving force generated by the driving coil, f=bil, wherein B is the magnetic field strength, I is the current in the coil, L is the coil length, and the driving force received by the coil under the driving of the constant current circuit is a fixed value; fd is a damping force generated by a damping coil, and can be a fixed value or have an equal ratio relation with F, and is different according to the hardware structure and the use requirement of the automatic aperture, but Fd is necessarily smaller than F; fr is mechanical resistance generated by a diaphragm movement structural member, and comprises friction force between a diaphragm blade and a shell and electrostatic attraction force generated by the diaphragm blade after movement friction, wherein the static friction force and the dynamic friction force can be considered to be equal, and the electrostatic attraction force can be generated before starting or not generated before starting and is generated after the diaphragm blade moves and rubs; fm is the attractive force between the external iron block and the magnetic core, the magnitude of Fm is related to the distance between the iron block and the magnetic core, the further the magnetic pole is from the iron block, the smaller the attractive force between the iron block and the magnetic core, fm=mh, where m is the magnetic pole strength, H is the magnetic field strength, and the magnetic field strength generated by the magnetic pole is inversely proportional to the third power of the distance r between the iron block and the magnetic core. When the driving force F > fm+fd+fr, the rotor starts to rotate, and if the electrostatic force increases with friction, the diaphragm stops acting when f=fm+fd+fr.
Because the electrostatic force is unstable, under the condition of the same driving force, the opening and closing degree of the aperture can be different due to the influence of the electrostatic force, and the positioning precision of the aperture can be seriously influenced by the electrostatic force. If the existence of electrostatic force is not considered, when f=fm+fd+fr (where Fr refers only to friction force), the diaphragm may be stabilized at a fixed position, where Fm decreases as the distance between the iron block and the magnetic core increases, and F may decrease as the opening and closing degree of the diaphragm becomes larger.
In order to eliminate the influence of electrostatic force, fm is increased, that is, the distance between the iron block and the magnetic core is reduced, and Fr is negligible when Fm is much larger than Fr (Fm is an exponential multiple of Fr). When Fm is increased, the driving force F is also increased, and the size of F can be adjusted by adjusting the damping force Fd of the damping coil, so that the opening and closing speed of the aperture is controlled. In the embodiment of the application, the opening and closing speed of the aperture is controllable, so that the action of the aperture blade is more stable, and the mechanical abrasion of the aperture blade caused by too fast opening and closing is reduced.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments.
The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.
Claims (10)
1. An aperture driving circuit, wherein the aperture comprises a driving coil and a damping coil, the circuit comprising:
The voltage superposition operation module and the integration amplification module;
The voltage superposition operation module comprises: the first resistor, the second resistor, the third resistor, the fourth resistor and the first capacitor;
The first end of the first resistor is used for being connected with a second voltage end, the second end of the first resistor is connected with the first end of the second resistor, the first end of the third resistor and the first end of the first capacitor, and the second end of the first capacitor is grounded; the second voltage end is used for being connected with a Pulse Width Modulation (PWM) signal;
The second end of the second resistor is connected with the non-inverting input end of the integral amplifying module, and the second end of the second resistor is also used for connecting a negative feedback voltage end and a first voltage end of the damping coil; the first voltage end is used for accessing a voltage signal with a preset amplitude;
The second end of the third resistor is connected with the first end of the fourth resistor and the inverting input end of the integration amplifying module, and the second end of the fourth resistor is used for being connected with the positive feedback voltage end of the damping coil;
the output end of the integral amplifying module is used for being connected with the driving voltage input end of the driving coil;
The driving voltage output by the integrating and amplifying module is as follows:
；
"UDRV +" is the start voltage of the diaphragm driving voltage in the switching state from rest to operation, R3 is the resistance value of the third resistor, U3 is the output voltage of the second output end of the voltage superposition operation module, the second output end of the voltage superposition operation module is connected with the inverting input end of the integrating amplification module, U4 is the voltage of the two ends of the first capacitor,R4 is the resistance value of the fourth resistor, uc is the equivalent voltage of the damping coil, rc is the equivalent resistance of the damping coil, t is a time constant, and C is the capacitance value of the first capacitor.
2. The diaphragm driving circuit of claim 1, wherein the diaphragm driving circuit further comprises: the reference partial pressure following module and the signal shaping module;
The reference voltage division following module is used for outputting the voltage signal with the preset amplitude value to the first voltage end;
The signal shaping module is used for responding to the control of the processor and outputting PWM signals with specified duty ratio to the second voltage terminal.
3. The diaphragm driving circuit of claim 1, wherein the integrating amplifying module comprises:
A first operational amplifier, a second capacitor, a third capacitor, a fifth resistor:
The first operational amplifier non-inverting input end is connected with the second end of the second resistor, and the first operational amplifier inverting input end is connected with the first end of the second capacitor, the first end of the third capacitor and the second end of the third resistor;
the high-voltage input end of the first operational amplifier is used for being connected with a first power supply, and the low-voltage input end of the first operational amplifier is grounded;
The output end of the first operational amplifier is connected with the second end of the second capacitor and the second end of the fifth resistor, and the output end of the first operational amplifier is also used for being connected with the driving voltage input end of the aperture;
The second end of the third capacitor is connected with the first end of the fifth resistor.
4. The diaphragm driving circuit according to claim 2, wherein the reference partial pressure following module includes:
A second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, and a sixth capacitor:
the non-inverting input end of the second operational amplifier is connected with the first end of the sixth resistor, the first end of the fourth capacitor and the first end of the seventh resistor, and the inverting input end of the second operational amplifier is connected with the first end of the eighth resistor and the first end of the sixth capacitor;
The high-voltage input end of the second operational amplifier is connected with the second end of the sixth resistor and the first end of the fifth capacitor, and the high-voltage input end of the second operational amplifier is also used for being connected with a first power supply;
The output end of the second operational amplifier is connected with the second end of the eighth resistor and the second end of the sixth capacitor, and the output end of the second operational amplifier is also used for being connected with the first voltage end;
The low voltage input end of the second operational amplifier, the second end of the fourth capacitor, the second end of the seventh resistor and the second end of the fifth capacitor are grounded.
5. The aperture driving circuit according to claim 2, wherein the signal shaping module comprises: third operational amplifier, ninth resistor:
the non-inverting input end of the third operational amplifier is used for being connected with an input voltage signal end of the processor, the inverting input end of the third operational amplifier is connected with the first end of the ninth resistor, the output end of the third operational amplifier and the second voltage end, the high voltage input end of the third operational amplifier is used for being connected with a first power supply, and the second end of the ninth resistor and the low voltage input end of the third operational amplifier are grounded.
6. A video camera, comprising: a processor, an aperture, and an aperture driving circuit as claimed in any one of claims 1 to 5;
The processor is used for determining a target duty ratio corresponding to the target opening degree of the aperture and sending a PWM signal of the target duty ratio to the aperture driving circuit;
The diaphragm driving circuit is used for responding to the PWM signal of the target duty ratio and sending a driving voltage signal to the driving voltage input end of the diaphragm;
The aperture is used for responding to the driving voltage signal and opening to the target opening degree.
7. The camera of claim 6, wherein a driving voltage input end of the driving coil is connected to an output end of the integrating amplifying module, a negative feedback voltage end of the damping coil is connected to the first voltage end, and a positive feedback voltage end of the damping coil is connected to a second end of the fourth resistor;
the driving coil is used for generating a driving magnetic field under the driving of the aperture driving circuit;
The damping coil is used for generating a damping magnetic field under the action of the driving coil and feeding back induced voltage to the aperture driving circuit through the positive feedback voltage end and the negative feedback voltage end.
8. The camera of claim 7, wherein the drive coil is wound side-by-side or overlapping the damping coil.
9. The camera of claim 7, wherein the aperture further comprises: the magnetic core rotor, the aperture deflector rod, the aperture blade and the ferromagnetic metal;
The ferromagnetic metal is arranged outside the driving coil and the damping coil, the magnetic core rotor is positioned inside the driving coil and the damping coil, the aperture deflector rod is arranged on the magnetic core rotor, and the aperture deflector rod rotates along with the rotation of the magnetic core rotor; the end part of the aperture deflector rod is directly or indirectly contacted with the aperture blade, and the rotation of the aperture deflector rod drives the aperture blade to be opened or closed.
10. The camera of claim 9, wherein an attractive force between the core rotor and the ferromagnetic metal is an exponential order of magnitude of an aperture blade resistance, wherein the aperture blade resistance includes a frictional force and an electrostatic attractive force of the aperture blade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410867712.7A CN118413730B (en) | 2024-07-01 | 2024-07-01 | Aperture driving circuit and camera |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410867712.7A CN118413730B (en) | 2024-07-01 | 2024-07-01 | Aperture driving circuit and camera |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118413730A CN118413730A (en) | 2024-07-30 |
| CN118413730B true CN118413730B (en) | 2024-10-01 |
Family
ID=91983361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410867712.7A Active CN118413730B (en) | 2024-07-01 | 2024-07-01 | Aperture driving circuit and camera |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118413730B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107613220A (en) * | 2017-09-30 | 2018-01-19 | 深圳市艾特智能科技有限公司 | Camera aperture drive circuit |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5919471A (en) * | 1982-07-24 | 1984-01-31 | Asahi Optical Co Ltd | Iris control circuit of video camera |
| JP2520491B2 (en) * | 1989-12-12 | 1996-07-31 | キヤノン電子株式会社 | Optical equipment |
| JP3875177B2 (en) * | 2002-10-30 | 2007-01-31 | 株式会社タムロン | Aperture device and video camera and digital still camera equipped with the same |
| JP5388522B2 (en) * | 2008-09-22 | 2014-01-15 | キヤノン株式会社 | Imaging apparatus and control method thereof |
| JP2010081202A (en) * | 2008-09-25 | 2010-04-08 | Rohm Co Ltd | Gain control circuit and class d power amplifier |
| CN201556011U (en) * | 2009-12-10 | 2010-08-18 | 浙江大华技术股份有限公司 | Auto iris driving circuit for internet protocol camera in safety monitoring field |
| CN102006419B (en) * | 2010-09-17 | 2013-01-02 | 惠州Tcl移动通信有限公司 | Mobile terminal with automatic focusing driving circuit and driving circuit thereof |
| US20190206338A1 (en) * | 2017-12-29 | 2019-07-04 | Shenzhen China Star Optoelectronics Technology Co. Ltd. | Voltage control circuit, display device and voltage control method |
| US20200036872A1 (en) * | 2018-07-24 | 2020-01-30 | Gopro, Inc. | Module isolation |
| CN210113734U (en) * | 2019-06-27 | 2020-02-25 | 浙江大华技术股份有限公司 | Automatic aperture control circuit and system |
| CN113541692A (en) * | 2021-08-17 | 2021-10-22 | 北京华峰测控技术股份有限公司 | Integrating circuit and source-test module |
-
2024
- 2024-07-01 CN CN202410867712.7A patent/CN118413730B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107613220A (en) * | 2017-09-30 | 2018-01-19 | 深圳市艾特智能科技有限公司 | Camera aperture drive circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118413730A (en) | 2024-07-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW200845588A (en) | Differential amplitude controlled sawtooth generator | |
| CN106462030B (en) | Lens driver circuit with ring compensation | |
| CN1879285B (en) | DC/DC Converter | |
| CN118413730B (en) | Aperture driving circuit and camera | |
| CN118413731B (en) | Video camera | |
| JPS61144476A (en) | Solenoid driving device | |
| JP2885940B2 (en) | Fan control method and circuit device | |
| CN101106325A (en) | Switching regulator | |
| CN220249098U (en) | Constant-current control circuit of electromagnetic valve | |
| CN210113734U (en) | Automatic aperture control circuit and system | |
| CN112445266B (en) | Adjusting circuit and adjusting method for charging cut-off current | |
| CN106712598B (en) | Motor rotating speed closed-loop control circuit | |
| CN112769334B (en) | Control circuit of power supply circuit and power supply circuit | |
| CN208737078U (en) | Energization motor self-checking device | |
| CN115917944A (en) | Control circuit for controlling power supply | |
| CN108267645B (en) | Duty ratio detection circuit | |
| US4355268A (en) | Motor control apparatus | |
| JPS59108455A (en) | Automatic stop controller of automatic stop lens for cctv camera | |
| CN118631070B (en) | Push-pull power supply circuit and driver chip | |
| CN117977923B (en) | Inductance peak current and duty cycle regulating circuit | |
| CN216774845U (en) | Circuit assembly, image pickup device and electronic device | |
| CN115800985B (en) | Driving circuit for improving turn-on current characteristic of electronic load | |
| CN219831240U (en) | Zero crossing point detection circuit applied to synchronous rectification mode of motor driving chip | |
| JPH0450906A (en) | Adjusting mechanism for camera lens | |
| CN117311057A (en) | Control circuit suitable for automatic aperture |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |