CN112218413A

CN112218413A - High-efficiency high-power isolation dimming signal amplifying circuit

Info

Publication number: CN112218413A
Application number: CN202010917434.3A
Authority: CN
Inventors: 石良泉; 蔡滨锋; 魏思沯
Original assignee: Xiamen Iotcomm Technology Co ltd
Current assignee: Xiamen Iotcomm Technology Co ltd
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2021-01-12
Anticipated expiration: 2040-09-03
Also published as: CN112218413B

Abstract

An efficient high-power isolation dimming signal amplification circuit, comprising: a dimming output unit for output adjustment of a voltage to realize a dimming output voltage capable of increasing an output current; the dimming output unit is provided with a feedback receiving end; a dimming input unit for adjusting a dimming input signal, the dimming input unit having a first output terminal; the feedback adjusting unit is connected with the first output end and the feedback receiving end, and the feedback adjusting unit is used for enabling the dimming output unit to adjust the dimming output voltage according to a feedback signal of the feedback adjusting unit.

Description

High-efficiency high-power isolation dimming signal amplifying circuit

Technical Field

The invention relates to the field of electricity, in particular to a high-efficiency high-power isolation dimming signal amplifying circuit.

Background

With the development of intelligent lighting management systems for tunnels, the need to use centralized remote dimming at tunnel lamps has grown year by year. The tunnel centralized dimming control equipment plays a role in centralized management of tunnel light in tunnel light control and has multi-channel dimming output control capability.

Centralized dimming control devices, typically located in the power distribution equipment, do not provide for high power analog dimming signal output on the channels.

The common tunnel lamp mainly uses centralized remote dimming equipment, the output of the centralized remote dimming equipment is basically multi-channel Direct Current (DC)0-10V analog dimming signal output, and the output of each channel is operational amplifier output and basically does not exceed 20 mA. In the remote dimming line, the dimming distance cannot be further due to the impedance in the line. Meanwhile, under the condition that the terminal load is loaded, the quantity of the loaded loads is small due to the limitation of the output power of the terminal load.

Disclosure of Invention

The invention aims to provide a high-efficiency high-power isolation dimming signal amplification circuit, which realizes the functions of isolating an analog dimming signal, amplifying the high-efficiency analog dimming signal, preventing self faults from influencing the output back stage and the like.

In order to solve the above problems, the present invention provides a high-efficiency high-power isolation dimming signal amplifying circuit, which includes: a dimming output unit for output adjustment of a voltage to realize a dimming output voltage capable of increasing an output current; the dimming output unit is provided with a feedback receiving end; a dimming input unit for adjusting a dimming input signal, the dimming input unit having a first output terminal; the feedback adjusting unit is connected with the first output end and the feedback receiving end, and the feedback adjusting unit is used for enabling the dimming output unit to adjust the dimming output voltage according to a feedback signal of the feedback adjusting unit.

Optionally, the dimming input unit includes a dimming input isolation unit, and the dimming input isolation unit is configured to perform analog isolation on the dimming input signal.

Optionally, the dimming input unit further includes a pull-down selection unit, the pull-down selection unit includes a first selection resistor and a second selection resistor, the first selection resistor is connected to the signal input end at a positive end and grounded at a negative end, and the second selection resistor is connected to the signal input end at a positive end and connected to the voltage stabilizing end of the voltage stabilizing device at a negative end.

Optionally, the power supply further includes an isolation voltage reduction unit, where the isolation voltage reduction unit is configured to convert an ac power supply into a dc power supply, and the dc power supply includes a first power supply voltage end and a second power supply voltage end.

Optionally, the second power supply voltage terminal is connected to a reference voltage dividing circuit, and the reference voltage dividing circuit has a reference voltage terminal; the feedback adjusting unit comprises a subtracter and an adder, wherein the positive phase input end of the subtracter is connected with the reference voltage end, and the negative phase input end of the subtracter is connected with the first output end;

the dimming output unit is provided with an output voltage division circuit which is provided with an output voltage division end; the output end of the subtracter and the output voltage-dividing end of the output voltage-dividing circuit are connected with the positive-phase input end of the adder; the output end of the adder is connected to the feedback receiving end of the dimming output unit.

Optionally, the feedback adjusting unit further includes a reference follower, and the reference voltage terminal is connected to the positive input terminal of the subtractor after being connected to the reference follower.

Optionally, the feedback adjustment unit further includes a first output follower, and the first output end passes through the first output follower and then is connected to the negative input end of the subtractor.

Optionally, the feedback adjustment unit further includes an output voltage division follower, and the output voltage division end is connected to the positive phase input end of the adder after passing through the output voltage division follower.

Optionally, the dimming output unit includes a failure protection unit, and the failure protection unit is disposed at an output end of the dimming output unit.

Optionally, the failure protection unit includes an enhancement NMOS transistor.

In one aspect, the invention provides a high-efficiency high-power isolation dimming signal amplifying circuit, which ensures that the dimming signal input is equal to the dimming signal output and has high precision.

Furthermore, the dimming input unit of the high-efficiency high-power isolation dimming signal amplifying circuit is used for inputting a dimming signal, the dimming output unit is used for outputting the dimming signal, and the input and the output are completely isolated from each other to avoid interference.

Furthermore, the high-efficiency high-power isolation dimming signal amplifying circuit has a high-power voltage conversion function, high-efficiency direct current analog dimming output, and the advantages of fault high resistance and no influence on external equipment.

Furthermore, the high-efficiency high-power isolation dimming signal amplifying circuit is provided with a closed-loop feedback system with input signals, can well carry out input and output following of dimming signals, and has the precision reaching 1 percent, and can realize large output current of analog dimming signals, and can achieve the aim of supporting 2A current output according to power matching of a power supply.

Furthermore, the high-efficiency high-power isolation dimming signal amplifying circuit can be widely applied to centralized dimming equipment and dimming relay equipment in the field of road lighting, can be used in occasions such as tunnel intelligent lighting and the like,

drawings

FIG. 1 is a circuit block diagram of an embodiment of a high-efficiency high-power isolation dimming signal amplifying circuit;

FIG. 2 is a schematic circuit diagram of a first portion of the isolation buck unit of FIG. 1;

FIG. 3 is a schematic diagram of a second portion of the isolation buck unit of FIG. 1;

FIG. 4 is a schematic circuit diagram of a third portion of the isolation buck unit of FIG. 1;

fig. 5 is a schematic circuit diagram of the dimming input unit of fig. 1;

FIG. 6 is a schematic circuit diagram of a first portion of the feedback regulation unit of FIG. 1;

fig. 7 is a schematic circuit diagram of a second part of the feedback adjusting unit and a schematic circuit diagram of the dimming output unit in fig. 1.

Detailed Description

As mentioned in the background, the centralized remote dimming device of the common tunnel lamp has corresponding disadvantages. These dimming devices mostly use an operational amplifier to amplify and output signals, and at this time, the basic output is only about 20mA due to the limited output capability of the operational amplifier. The devices need to expand the current, and a transistor is added in the rear stage of the devices to introduce a feedback system. Although the output current can be amplified to a certain degree by the structure, the analog dimming signal used by the common street lamp and the tunnel lamp is in a DC0-10V interval, so that the following reasons are met:

(1) when a triode (transistor) is used for current expansion, Vbe junction voltage drop is inevitably caused, and the voltage drop is increased along with the increase of output current, so that the low end of the dimming voltage is not up to 0V;

(2) at high power, the triode operates in a linear amplification region due to the use of the triode (transistor) for current spreading, meaning that 50% of the power dissipation is on the transistor when the specific output voltage is 5V when the output voltage is in the range of DC 0-10V.

Therefore, the conventional method has problems such as low efficiency and large heat generation amount. In addition, in the application of centralized remote dimming of the common tunnel lamp, due to the long distance of the dimming signal line, a plurality of connected loads are easy to introduce interference on the line, and under the condition that a terminal of a specific load is in fault or the installation and wiring are wrong, the fault is easily introduced into the dimming line, so that equipment on the whole line is damaged or stopped.

Therefore, the invention provides a novel high-efficiency high-power isolation dimming signal amplifying circuit, which aims to solve the problem of high-efficiency dimming power signal output and can realize mutual isolation among signals.

For a more clear presentation, the invention is described in detail below with reference to the accompanying drawings.

An embodiment of the invention provides a high-efficiency high-power isolation dimming signal amplifying circuit, please refer to fig. 1 to 7.

Referring to fig. 1, the high-efficiency high-power isolation dimming signal amplifying circuit includes:

a dimming output unit 100, the dimming output unit 100 being used for output adjustment of voltage to realize a dimming output voltage capable of increasing an output current; the dimming output unit 100 has a feedback receiving terminal;

a dimming input unit 200, the dimming input unit 200 being configured to adjust a dimming input signal, the dimming input unit 200 having a first output terminal;

and a feedback adjusting unit 300, wherein the feedback adjusting unit 300 is connected to the first output terminal and the feedback receiving terminal, and the feedback adjusting unit 300 is configured to enable the dimming output unit 100 to adjust the dimming output voltage according to a feedback signal of the feedback adjusting unit 300.

Referring to fig. 1, the high-efficiency high-power isolation dimming signal amplifying circuit further includes an isolation step-down unit 400, where the isolation step-down unit 400 is configured to convert an ac power into a dc power, and the dc power includes a first power supply voltage terminal and a second power supply voltage terminal.

Fig. 2 to fig. 4 are schematic diagrams of specific circuits of the isolation step-down unit 400.

Fig. 2 shows that the isolating voltage-reducing unit 400 has a fuse F1 connected to the ac input positive terminal P1, and an overvoltage protection component, specifically a varistor RVM1, is connected between the ac input positive terminal P1 and the ac input negative terminal P2, and further a varistor of type 14D561k may be selected.

Fig. 2 shows that after connecting with the inductor through the corresponding resistor RT1, the isolated voltage step-down unit 400 further has a bridge rectifier portion, and then through the corresponding plurality of capacitors and the magnetic bead FB1, the power supply is enabled to be converted from ac to dc and interference is prevented.

Fig. 3 further shows that after passing through an isolator T1 (which may be implemented by a device of EE1622 type), voltage conversion is performed, and finally, in cooperation with a regulator chip U1, a first supply voltage is output from a first supply voltage terminal (shown as VCC12V shown in the upper right corner of fig. 3), where the first supply voltage may be 12V.

Fig. 4 further shows that after voltage division by the resistor R11, the resistor R12, and the resistor R13, and the voltage regulator device U2 (may adopt a CJ431 chip), the present embodiment further utilizes the isolation voltage dropping unit 400 to output a second supply voltage, where the second supply voltage may be 5V. The second supply voltage terminal is shown as VCC5V shown in the upper right hand corner of fig. 4.

Referring to fig. 1 and 5 in combination, the dimming input unit 200 includes a dimming input isolation unit 210 shown in fig. 1, and the dimming input isolation unit 210 is used for analog isolation of the dimming input signal. The dimming input isolation unit 210 in fig. 1 may be implemented by using the analog signal isolation chip U3 shown in fig. 5, and the analog signal isolation chip U3 may specifically adopt a chip with a model TE 5554N.

The isolation chip U3 may be a 1:1 dc0-10V analog signal isolation module, the block on the right side of the isolation chip U3 provides one path of isolated power supply output, and the voltage output of the first output terminal is realized through a voltage division circuit (divided by a resistor R20 and a resistor R21), and the first output terminal is shown as a port SP3 in fig. 5.

Referring to fig. 1 and 5 in combination, the dimming input unit 200 includes a pull-up/pull-down selection unit 220 in addition to the dimming input isolation unit 210. The pull-up/down select unit 220 of fig. 1 is specifically shown in fig. 5 as a circuit with the signal positive input terminal P3 and the signal negative input terminal P4 shown to the right and the analog signal isolation chip U3 shown to the left.

Specifically, fig. 5 shows that the pull-up/down selection unit 220 includes a first selection resistor R15 and a second selection resistor R16 (alternatively arranged, which means that only one of the first selection resistor R15 and the second selection resistor R16 may exist in an actual circuit), a positive terminal of the first selection resistor R15 is connected to the signal input terminal and a negative terminal thereof is grounded, a positive terminal of the second selection resistor R16 is connected to the signal input terminal and a negative terminal thereof is connected to a voltage stabilizing terminal of a voltage stabilizing device (specifically, the selection is implemented by a voltage stabilizing device U4, and the voltage stabilizing device U4 may be implemented by a CJ431 chip).

The pull-down selection unit 220 also includes other corresponding resistors and capacitors, please refer to the peripheral circuit structure of the left pin of the analog signal isolation chip U3 in fig. 5. The pull-up and pull-down selection unit 220 may be used to select a weak pull-up or a weak pull-down as an initial state of the dimming control circuit.

With reference to fig. 5, fig. 1 and fig. 6, in the present embodiment, the second power supply voltage terminal is connected to the reference voltage dividing circuit 420, and the reference voltage dividing circuit 420 has a reference voltage terminal; the second supply voltage terminal is shown at VCC5V at the top left corner in fig. 6, and the reference voltage divider circuit 420 is shown as resistor R22 and resistor R23 in fig. 6, and the voltage terminal between resistor R22 and resistor R23 is the reference voltage terminal.

In this embodiment, the voltage output from the reference voltage terminal is controlled to be 0.6V, which is that according to this embodiment, the normal feedback voltage of the chip U5 is selected to be 0.6V, and the feedback voltage is connected to the 4 th pin of the chip U5.

As further shown in fig. 1, the feedback adjusting unit 300 comprises a subtractor 310 (shown in fig. 6 as being implemented by a subtractor U6B) and an adder 320 (shown in fig. 7 as being implemented by an adder U6C), wherein a positive phase input terminal of the subtractor 310 is connected to the reference voltage terminal (between the resistor R22 and the resistor R23 in fig. 6), and a negative phase input terminal of the subtractor 310 is connected to the first output terminal (the negative phase input terminal of the subtractor 310 is not directly connected to the first output terminal, but is connected after passing through a follower U6D and a resistor R26); the first output is shown in FIG. 5 as port SP3, which is also port SP3 in FIG. 6.

Referring to fig. 1 and 7 in combination, the dimming output unit 100 in fig. 1 includes the circuit shown in fig. 7, a circuit enclosed by a dashed box (not labeled) belongs to a portion of the feedback adjusting unit 300, and a circuit outside the dashed box belongs to the circuit of the dimming output unit 100.

As can be seen from fig. 7, the dimming output unit 100 has an output voltage division circuit having an output voltage division terminal; specifically, the output voltage dividing circuit comprises a resistor R34 and a resistor R35 which are connected to a 2 nd pin and a 6 th pin of a U5 chip, and the middle of the resistor R34 and the resistor R35 is used as the output voltage dividing end. The output voltage dividing terminal is connected to a follower U7A (i.e., a first output follower 340), as will be further described later.

The output end of the subtractor 310 and the output voltage-dividing end of the output voltage-dividing circuit are connected with the non-inverting input end of the adder 320; the output terminal of the adder 320 is connected to the feedback receiving terminal of the dimming output unit 100.

Referring to fig. 1 and fig. 6 in combination, fig. 1 shows that the feedback adjustment unit 300 further includes a reference follower 330, and fig. 6 shows that the reference follower 330 may be implemented by a follower U6A; at this time, the reference voltage terminal (not labeled), i.e., the voltage terminal between the resistor R22 and the resistor R23, is connected to the reference follower 330 (follower U6A), then connected to the resistor R24, and then connected to the non-inverting input terminal of the subtractor 310 (subtractor U6B) through the reference follower 330 and the resistor R24.

Referring to fig. 1 and fig. 6 in combination, the feedback adjusting unit 300 further includes a first output follower 340, and fig. 6 shows that the first output follower 340 may be implemented by a follower U6D; at this time, the first output terminal (port SP3) passes through the first output follower 340 (follower U6D), then is connected to the resistor R26, and then is connected to the negative input terminal of the subtractor 310 (subtractor U6B) through the reconnection resistor R26.

Referring to fig. 1, fig. 6 and fig. 7 in combination, fig. 1 shows that the feedback adjusting unit 300 further includes an output voltage division follower 350, and fig. 7 shows that the output voltage division follower 350 may be implemented by a follower U7A; the output voltage dividing terminal (i.e., the voltage terminal between the resistor R34 and the resistor R35) passes through the output voltage dividing follower 350 (follower U7A), then passes through the resistor R29, and then is connected to the non-inverting input terminal of the adder 320 (adder U6C) through the resistor R29. Meanwhile, as can be seen from fig. 6, the output terminal of the subtractor 310 (subtractor U6B) is shown as port SP4 in fig. 6, i.e., port SP4 in fig. 7, so it can be seen that the output terminal of the subtractor 310 (subtractor U6B) is connected to the resistor R28 in fig. 7, and then connected to the non-inverting input terminal of the adder 320 (adder U6C) through the resistor R28.

Referring to fig. 1 and 7 in combination, fig. 7 further shows that the dimming output unit 100 includes a fail-safe unit (not labeled differently), and the fail-safe unit is disposed at an output end of the dimming output unit 100. The fail safe unit comprises an enhanced NMOS transistor Q1 and a second supply voltage (VCC 12V) connected to the enhanced NMOS transistor Q1. The second power supply voltage is matched with the enhanced NMOS transistor Q1, so that the effects that: when the amplifying circuit fails, the enhancement NMOS transistor Q1 and the second power supply voltage can ensure that the positive terminal P5 of the output terminal of the dimming output unit 100 is not directly grounded, thereby preventing the connected load from directly failing to operate. That is, the fail-safe unit can at least maintain the load to be dimmed to maintain the corresponding operating state for a period of time, and the working personnel can use the period of time to perform the maintenance of the dimming circuit as soon as possible.

In combination with the above, in this embodiment, an independent isolation voltage-reducing unit 400 is added to the dimming circuit to provide a stable power supply for the circuit, and the isolation voltage-reducing unit 400 has a voltage-stabilizing chip U1 (which may be implemented by a chip of type INN2603 k), so as to provide a stable first power supply voltage (12V), and at the same time, a chip U2 (which may be implemented by a voltage stabilizer of type TL 431) is further used to output a second power supply voltage (which may be 5.0V), and the second power supply voltage serves as a further more stable voltage and may be used as a power supply for a corresponding regulating circuit portion.

The dimming output unit 100 is a high-efficiency voltage conversion structure, the maximum efficiency of the dimming output unit 100 can reach more than 90%, and the heating value is extremely low. The dimming output unit 100 can make the output current of the whole circuit reach 500mA when matching with the whole circuit, and has the capability of expanding to 2A.

In the failure protection unit, the introduction of the output MOS tube (namely an enhanced NMOS tube Q1) plays a role of prohibiting the conduction of the MOS tube when the dimming signal amplifier circuit fails, and forming an output high-resistance state, so that the load carried by the output is not pulled down, and the initial dimming state of the load is not influenced.

The feedback adjusting unit 300 performs adjustment using an operational circuit built with an operational amplifier. In this embodiment, each operational amplifier may be a rail-to-rail low noise operational amplifier. These operational amplifiers form the above-described followers, subtractors, adders, and the like in accordance with the respective connections.

Follower circuits are respectively introduced after a reference voltage end (reference regulation), a first output end (dimming input regulation) and an output voltage division end (output feedback regulation) to carry out conversion of high-resistance input and low-resistance output, so that the loading capacity of the circuit is higher.

The principle of the feedback adjusting unit 300 includes using a reference voltage (0.6V) provided by a reference voltage terminal to offset a base voltage (also 0.6V, also referred to as a reference voltage) of a feedback pin (4 th pin) of a chip U5 (which may be implemented by TPS54202 DDCR) in the dimming output unit 100;

in the signal feedback process, the reference voltage provided by the reference voltage terminal and the voltage at the first output terminal (port SP3) are subtracted by the subtractor 310 (subtractor U6B) to obtain a result, and the result is added to the output feedback voltage (i.e. the voltage at the output divided terminal, i.e. the voltage between the resistor R34 and the resistor R35), and the obtained value is sent to the feedback pin of the chip U5.

In the above process, the formula of the feedback operation is:

V(out-adder)＝V(base)-V(IN)+V(OUT-FB)。

in the formula, V (base) is a reference voltage (fixed reference value), V (in) is a divided voltage value of the dimming signal input, i.e., a voltage of the first output terminal (port SP3), and V (OUT-FB) is a divided voltage value of the output divided voltage (i.e., a divided voltage of the output signal). It should be particularly noted that V (out-adder) is not the output voltage of the dimming output unit 100, but the voltage of the 4 th pin of the chip U5 fed back by the adder 320 (the adder U6C). According to the selection of the device parameters, in the embodiment, when V (out-adder) is 0.6V, the closed loop is kept stable.

Thus, a closed-loop feedback system is formed in which the input signal participates.

According to the above formula, when V (OUT-adder) ═ V (base), V (in) needs to be equal to V (OUT-FB), and then the dimming signal input is equal to the dimming signal output, the minimum power supply of the dimming signal can be expanded to 0V, and the output accuracy reaches 1%.

In this embodiment, the output feedback voltage is proportional to the output voltage of the dimming output unit 100 through the circuit structure and the selection of the corresponding device parameters, and the output feedback voltage of the dimming output unit 100 varies within 0-10V, while the output feedback voltage varies within 0-0.6V. In this embodiment, the circuit structure and the selection of the corresponding device parameters make the first output terminal voltage and the dimming input voltage in a direct proportion relationship, the dimming input voltage changes within 0-10V, and the first output terminal voltage correspondingly changes within 0-0.6V.

On the basis of the above, in a specific scenario, it is assumed that in the pull-up/down selection unit 220, the first selection resistor R15 is selectively arranged (i.e., the second selection resistor R16 does not exist at this time, and the structure of the voltage regulator device U4 and the like may be left vacant in the circuit). At this time, the following three voltage conditions can be used for the scenario description.

In case one, when the input voltage of the dimming signal is 0V, that is, in fig. 5, the signal positive input terminal P3 and the signal negative input terminal P4 input the 0V dimming signal, after passing through the pull-up and pull-down selection unit 220 and the dimming input isolation unit 210, the voltage of the first output terminal (port SP3) is also 0V, that is, V (in) is 0V; at this time, after the subtraction is performed on the reference voltage by the subtractor 310 (the subtractor U6B), the original voltage value (0.6V) is still protected, the reference voltage and the output feedback voltage are added, and the obtained value is sent to the feedback pin of the chip U5, and according to the above formula, the output feedback voltage is also adjusted to 0V by the feedback, that is, the output voltage of the entire dimming output unit 100 is 0V.

In case two, when the input voltage of the dimming signal is 4V, that is, in fig. 5, the 4V dimming signal is input to the signal positive input terminal P3 and the signal negative input terminal P4, after passing through the pull-up and pull-down selection unit 220 and the dimming input isolation unit 210, the voltage of the first output terminal (port SP3) is 0.2V, that is, V (in) is 0.2V; at this time, the reference voltage is subtracted by the subtractor 310 (the subtractor U6B) to 0.6-0.2, which is 0.4V, and the added value of the reference voltage and the output feedback voltage is then fed to the feedback pin of the chip U5, and as can be seen from the above formula, the output feedback voltage is also adjusted to 0.2V by feedback, that is, the output voltage of the entire dimming output unit 100 is 4V.

In case three, when the input voltage of the dimming signal is 10V, that is, in fig. 5, the 10V dimming signal is input to the signal positive input terminal P3 and the signal negative input terminal P4, after passing through the pull-up and pull-down selecting unit 220 and the dimming input isolating unit 210, the voltage of the first output terminal (port SP3) is 0.6V, that is, V (in) is 0.6V; at this time, the reference voltage is subtracted by the subtractor 310 (the subtractor U6B) to 0.6-0.6V, and the added value of the reference voltage and the output feedback voltage is sent to the feedback pin of the chip U5, and according to the above formula, the output feedback voltage is also adjusted to 0.6V by feedback, that is, the output voltage of the entire dimming output unit 100 is 10V.

The above scenario can show that the circuit of the present embodiment ensures that the dimming signal input is equal to the dimming signal output, and has high precision.

It should be noted that, in other embodiments, the voltage range and the ratio of the analog dimming signal of the corresponding high-efficiency high-power isolation dimming signal amplifying circuit may be changed according to parameters in the circuit.

It should be noted that, in other embodiments, when the second selection resistor R16 is selectively disposed in the pull-up/down selection unit 220 (i.e. the first selection resistor R15 does not exist at this time), the 10V dimming signal voltage value is input to the signal positive input terminal P3 and the signal negative input terminal P4, and the divided voltage value of the dimming signal input is a linear function of the negative slope.

In the high-efficiency high-power isolation dimming signal amplifying circuit provided by the embodiment, the dimming input unit 200 is used for inputting the dimming signal, the dimming output unit 100 is used for outputting the dimming signal, and the input and the output are completely isolated from each other, so that interference is avoided.

The high-efficiency high-power isolation dimming signal amplifying circuit provided by the embodiment has a high-power voltage conversion function, high-efficiency direct-current analog dimming output, and the advantages of high fault resistance and no influence on external equipment.

The high-efficiency high-power isolation dimming signal amplifying circuit provided by the embodiment has a closed-loop feedback system with input signal participation, can well carry out input and output following of dimming signals, and has the precision reaching 1 percent, and the embodiment realizes large output current of analog dimming signals, can be matched according to power supply power and achieves the aim of supporting 2A current output.

The high-efficiency high-power isolation dimming signal amplifying circuit provided by the embodiment can be widely applied to centralized dimming equipment and dimming relay equipment in the field of road lighting.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An efficient high-power isolation dimming signal amplification circuit, comprising:

a dimming output unit for output adjustment of a voltage to realize a dimming output voltage capable of increasing an output current; the dimming output unit is provided with a feedback receiving end;

a dimming input unit for adjusting a dimming input signal, the dimming input unit having a first output terminal;

the feedback adjusting unit is connected with the first output end and the feedback receiving end, and the feedback adjusting unit is used for enabling the dimming output unit to adjust the dimming output voltage according to a feedback signal of the feedback adjusting unit.

2. The high efficiency high power isolated dimming signal amplifying circuit according to claim 1, wherein the dimming input unit comprises a dimming input isolation unit for analog isolation of the dimming input signal.

3. The isolated high power dimming signal amplifying circuit according to claim 2, wherein the dimming input unit further comprises a pull-up and pull-down selection unit, the pull-up and pull-down selection unit comprises a first selection resistor and a second selection resistor, the first selection resistor is connected to the signal input terminal at the positive end and grounded at the negative end, and the second selection resistor is connected to the signal input terminal at the positive end and connected to the voltage stabilizing terminal of the voltage stabilizing device at the negative end.

4. The high efficiency high power isolated dimming signal amplifying circuit according to claim 3, further comprising an isolation buck unit for converting an ac power source to a dc power source, wherein the dc power source comprises a first supply voltage terminal and a second supply voltage terminal.

5. The high efficiency high power isolated dimming signal amplifying circuit according to claim 4, wherein the second supply voltage terminal is connected to a reference voltage divider circuit, the reference voltage divider circuit having a reference voltage terminal;

the feedback adjusting unit comprises a subtracter and an adder, wherein the positive phase input end of the subtracter is connected with the reference voltage end, and the negative phase input end of the subtracter is connected with the first output end;

the dimming output unit is provided with an output voltage division circuit which is provided with an output voltage division end;

the output end of the subtracter and the output voltage-dividing end of the output voltage-dividing circuit are connected with the positive-phase input end of the adder; the output end of the adder is connected to the feedback receiving end of the dimming output unit.

6. The high efficiency high power isolated dimming signal amplifying circuit according to claim 5, wherein the feedback adjusting unit further comprises a reference follower, and the reference voltage terminal is connected to the non-inverting input terminal of the subtractor after the reference follower.

7. The high efficiency high power isolated dimming signal amplifying circuit according to claim 6, wherein the feedback adjusting unit further comprises a first output follower, and the first output terminal is connected to the negative input terminal of the subtractor after passing through the first output follower.

8. The high efficiency high power isolated dimming signal amplifying circuit according to claim 7, wherein the feedback adjusting unit further comprises an output voltage division follower, and the output voltage division terminal is connected to the non-inverting input terminal of the adder after passing through the output voltage division follower.

9. The high efficiency high power isolated dimming signal amplifying circuit according to claim 1, wherein the dimming output unit comprises a fail safe unit disposed at an output terminal of the dimming output unit.

10. The high efficiency high power isolated dimming signal amplifying circuit according to claim 9, wherein the failure protection unit comprises an enhancement NMOS transistor.