CN216056308U - Thermal protection switch and motor using same - Google Patents
Thermal protection switch and motor using same Download PDFInfo
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- CN216056308U CN216056308U CN202122638339.2U CN202122638339U CN216056308U CN 216056308 U CN216056308 U CN 216056308U CN 202122638339 U CN202122638339 U CN 202122638339U CN 216056308 U CN216056308 U CN 216056308U
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Abstract
The utility model discloses a thermal protection switch and a motor using the same, and belongs to the technical field of thermal protection technology and motor equipment. The existing thermal protector cannot achieve a good power isolation effect, the measurement precision is +/-5 degrees, and good adaptation cannot be achieved for some special motors. The utility model relates to a thermal protection switch, which comprises a rectifying circuit, a voltage regulating circuit, a voltage acquisition and comparison circuit and a switch protection circuit. The voltage acquisition comparison circuit is provided with the thermistor and the comparator, and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can control the on-off action of the relay according to the output voltage of the CON port, so that the motor circuit can be effectively disconnected at high temperature, the motor and the power supply can be effectively isolated, and the motor can be effectively protected. Meanwhile, the utility model can effectively improve the thermal protection precision, has better user experience and is convenient for popularization and use.
Description
Technical Field
The utility model relates to a thermal protection switch and a motor using the same, and belongs to the technical field of thermal protection technology and motor equipment.
Background
The water pump is applied to various places of people's present life, but the process of water pump use, because the not use of quality of water to and the existence of each side harmful factor, can lead to the whole some friction that appears of water pump to make the operation that the water pump motor can not be fine, lead to the motor to generate heat.
In order to protect the motor and the stator coils from burning out, thermal protectors are typically used to protect the motor. At present used hot protector all carries out the guard action based on the heat conduction deformation of metal, this hot protector has two kinds of different metals to constitute, under the condition of motor normal operating, two kinds of metals in the hot protector are normal condition, and be in and connect the on-state, guarantee the normal operating of motor, when the motor appears generating heat unusually because of the external reason, hug closely two kinds of metals in the hot protector also can take place deformation for the change of temperature, will misplace under the condition of uniform temperature, become the off-state by the on-state, thereby the outage protects the motor not burnt out.
However, the protector has several disadvantages, and firstly, a better power isolation effect cannot be achieved, and since the protector is realized by the extensibility of metal, the extending direction cannot be well ensured, and the protector may be still in a conducting state after being deformed, so that burn-out may occur. Secondly, the measurement accuracy of the protector is +/-5 degrees, and the protector cannot be well adapted to some special motors.
SUMMERY OF THE UTILITY MODEL
Aiming at the defects of the prior art, the utility model aims to provide a voltage acquisition comparison circuit and a switch protection circuit, wherein the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can utilize the output voltage of the CON port to control the switching action of the relay, so that the motor circuit can be effectively disconnected at high temperature, and the thermal protection switch for effectively protecting the motor and the motor using the thermal protection switch are realized.
In order to achieve the above object, a first technical solution of the present invention is:
a thermal protection switch comprises a rectification circuit, a voltage regulation circuit, a voltage acquisition comparison circuit and a switch protection circuit;
the rectifying circuit is provided with at least one filter capacitor and is used for converting an input power supply into direct current and connecting the direct current with the voltage regulating circuit;
the voltage regulating circuit is provided with a transformer and is used for converting the direct current output by the rectifying circuit into a direct current power supply and supplying power to the voltage acquisition and comparison circuit;
the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
one of the positive pole or the negative pole of the comparator is electrically connected with the voltage regulating circuit through a resistor, the other pole of the comparator is electrically connected with the voltage regulating circuit through a thermistor, and the CON port of the comparator is electrically connected with the switch protection circuit;
when the anode voltage of the comparator is larger than the cathode voltage of the comparator, the CON port of the comparator outputs a Ut voltage;
when the anode voltage of the comparator is smaller than the cathode voltage of the comparator, the CON port of the comparator outputs 0V voltage;
the switch protection circuit is provided with a triode and a relay and is used for controlling the on-off of the motor switch circuit;
the triode is electrically connected with the CON port of the comparator and can control the switching action of the relay by utilizing the output voltage of the CON port;
when the comparator outputs the Ut voltage, the triode is conducted, and the relay is closed, so that the motor stops working;
when the comparator outputs 0V voltage, the triode is not conducted, the relay is not attracted, and the triode is in a release state, so that the motor works normally.
Through continuous exploration and test, the utility model is provided with a voltage acquisition comparison circuit and a switch protection circuit, wherein the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can utilize the output voltage of the CON port to control the on-off action of the relay, so that the motor circuit can be effectively disconnected at high temperature, the motor and the power supply can be effectively isolated, and the motor can be effectively protected.
Furthermore, compared with the prior art that the thermal protection of the motor is realized by utilizing metal deformation, the temperature coefficient of the thermistor is several times or even dozens of times of that of metal, so that the sensitivity is very high, and the temperature measurement application range is wider, therefore, the utility model utilizes the thermistor to ensure that the measurement precision can be stabilized within 1 ℃ so as to be suitable for various high-precision occasions.
Furthermore, the utility model can automatically complete the action of the relay by utilizing the sensing capability of the thermistor on the external temperature, can effectively improve the thermal protection precision, avoids the condition that the motor is burnt, realizes the thermal protection of the motor, and has the advantages of simple and practical scheme, low manufacturing cost, better user experience and convenient popularization and use.
As a preferable technical measure:
the rectifier circuit is a bridge rectifier circuit and further comprises a diode, a capacitor CX1 and a capacitor E6;
the diode converts the polarity of the sine wave negative half-wave by utilizing the single-phase conduction characteristic of the diode, so that single-phase pulsating direct current is obtained;
the capacitor CX1 and the capacitor E6 are used for converting single-phase pulsating direct current into relatively stable (relatively small fluctuation) direct current.
As a preferable technical measure:
the voltage regulating circuit further comprises a power switch power supply U2, a direct current voltage stabilizing chip U1, a capacitor C3 and a capacitor C5;
the power switching power supply U2 has a fixed switching frequency of 60HZ and is used for converting the power of 310V direct current into a +12V direct current power supply Ua;
the direct current voltage stabilizing chip U1 is used for stabilizing the +12V direct current power supply Ua into a +5V direct current power supply Ub;
and the capacitor C3 and the capacitor C5 are used for converting the +5V direct-current power supply Ub into a relatively stable 5V direct-current voltage source which is used as a power supply of the voltage acquisition comparison circuit.
As a preferable technical measure:
the voltage acquisition comparison circuit further comprises a resistor R7, a resistor R11, a resistor R10 and a resistor R9;
the resistor R7, the resistor R11 and the resistor R10 are electrically connected with the anode of the comparator;
the resistor R9 is electrically connected to the negative terminal of the comparator.
As a preferable technical measure:
the resistor R9 is a variable resistor, the resistance value of the resistor can be changed according to different temperature control requirements, so that the voltage input to the negative electrode of the comparator can be changed, the control result of the relay can be changed, and the protection temperature range can be changed by adjusting the adaptive resistor, so that the utility model has the advantages of wider application range, simple and practical scheme and low manufacturing cost.
As a preferable technical measure:
the resistance value of the thermistor at normal temperature is Rf1, and the resistance value at abnormal high temperature is Rf 2;
20KΩ≤Rf21≤30KΩ；
0.5KΩ≤Rf2≤4KΩ。
the abnormal high temperature is generally 100-160 ℃;
the normal temperature is generally-15 to 80 degrees.
As a preferable technical measure:
the triode is an NPN triode Q3;
the relay is a double-open double-switch relay.
As a preferable technical measure:
and Ut is greater than 0, and the value of Ut is equal to the output voltage of the voltage regulating circuit.
In order to achieve the above object, a second technical solution of the present invention is:
a thermal protection switch is provided, which comprises a thermal protection switch,
the device comprises a voltage acquisition comparison circuit and a switch protection circuit;
the voltage acquisition comparison circuit is provided with a thermistor RT and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor RT is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
one of the anode or the cathode of the comparator is electrically connected with a power supply through a resistor, the other electrode of the comparator is electrically connected with the power supply through a thermistor RT, and a CON port of the comparator is electrically connected with a switch protection circuit;
the switch protection circuit is provided with a relay and is used for controlling the on-off of a circuit of the equipment to be protected;
the relay is electrically connected with the port of the comparator CON, and the output voltage of the port of the comparator CON is utilized to control the on-off action of the relay so as to realize the on-off of the circuit of the equipment to be protected.
Through continuous exploration and test, the utility model is provided with a voltage acquisition comparison circuit and a switch protection circuit, wherein the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can utilize the output voltage of the CON port to control the switching action of the relay, so that the circuit of the equipment to be protected can be disconnected at high temperature, and the equipment to be protected is effectively protected.
Furthermore, the utility model can automatically complete the action of the relay by utilizing the sensing capability of the thermistor on the external temperature, thereby realizing the thermal protection of the equipment to be protected; compared with the prior art that the thermal protection of the equipment to be protected is realized by utilizing metal deformation, the thermal protection method and the device can effectively improve the thermal protection precision, avoid the situation that the equipment to be protected is burnt, have better user experience and are convenient to popularize and use.
Furthermore, the utility model adopts the relay for control, and can effectively realize power isolation; the thermistor can be used for stabilizing the measurement precision within 1 ℃ so as to be suitable for various high-precision equipment to be protected.
The equipment to be protected is electromechanical equipment or household appliances or electronic products.
For example, the thermal protection switch can be used on a motor or a socket or an electric heating device.
In order to achieve the above object, a third technical solution of the present invention is:
an electric motor using a thermal protection switch is provided,
including a thermal protection switch as described above.
The utility model can automatically complete the action of the relay by utilizing the sensing capability of the thermistor on the external temperature, can effectively improve the thermal protection precision, avoids the condition that the motor is burnt, realizes the thermal protection of the motor, and has the advantages of simple and practical scheme, low manufacturing cost, better user experience and convenient popularization and use.
Compared with the prior art, the utility model has the following beneficial effects:
through continuous exploration and test, the utility model is provided with a voltage acquisition comparison circuit and a switch protection circuit, wherein the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can control the on-off action of the relay according to the output voltage of the CON port, so that the motor circuit can be effectively disconnected at high temperature, the motor and the power supply can be effectively isolated, and the motor can be effectively protected.
Furthermore, compared with the prior art that the thermal protection of the motor is realized by utilizing metal deformation, the temperature coefficient of the thermistor is several times or even dozens of times of that of metal, so that the sensitivity is very high, and the temperature measurement application range is wider, therefore, the utility model utilizes the thermistor to ensure that the measurement precision can be stabilized within 1 ℃ so as to be suitable for various high-precision occasions.
Furthermore, the utility model can automatically complete the action of the relay by utilizing the sensing capability of the thermistor on the external temperature, can effectively improve the thermal protection precision, avoids the condition that the motor is burnt, realizes the thermal protection of the motor, and has the advantages of simple and practical scheme, low manufacturing cost, better user experience and convenient popularization and use.
Drawings
FIG. 1 is a block diagram of the system architecture of the present invention;
FIG. 2 is a diagram of a rectifier circuit according to the present invention;
FIG. 3 is a diagram of the voltage regulator circuit of the present invention;
FIG. 4 is a diagram of a voltage acquisition comparison circuit according to the present invention;
FIG. 5 is a structural logic diagram of the present invention;
fig. 6 is a structural diagram of the switch protection circuit of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.
On the contrary, the utility model is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the utility model as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
As shown in fig. 1, a thermal protection switch includes a rectifying circuit, a voltage regulating circuit, a voltage collecting and comparing circuit, and a switch protection circuit.
The rectifying circuit is provided with at least one filter capacitor and is used for converting an input power supply into direct current and connecting the direct current with the voltage regulating circuit;
the voltage regulating circuit is provided with a transformer and is used for converting the direct current output by the rectifying circuit into a direct current power supply and supplying power to the voltage acquisition and comparison circuit;
the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
one pole of the comparator is electrically connected with the voltage regulating circuit through a resistor, the other pole of the comparator is electrically connected with the voltage regulating circuit through a thermistor, and a CON port of the comparator is electrically connected with the switch protection circuit;
when the anode voltage of the comparator is larger than the cathode voltage of the comparator, the CON port of the comparator outputs a Ut voltage;
when the anode voltage of the comparator is smaller than the cathode voltage of the comparator, the CON port of the comparator outputs 0V voltage;
the switch protection circuit is provided with a triode and a relay and is used for controlling the on-off of the motor switch circuit;
the triode is electrically connected with the CON port of the comparator and can control the switching action of the relay according to the output voltage of the CON port;
when the comparator outputs the Ut voltage, the triode is conducted, and the relay is closed, so that the motor stops working;
when the comparator outputs 0V voltage, the triode is not conducted, the relay is not attracted, and the triode is in a release state, so that the motor works normally.
Through continuous exploration and test, the utility model is provided with a voltage acquisition comparison circuit and a switch protection circuit, wherein the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change; the switch protection circuit can control the switching action of the relay according to the output voltage of the CON port, so that the motor circuit can be disconnected at high temperature, and the motor can be effectively protected.
Furthermore, the utility model can automatically complete the action of the relay by utilizing the sensing capability of the thermistor on the external temperature, thereby realizing the thermal protection of the motor; compared with the prior art that the thermal protection of the motor is realized by utilizing metal deformation, the utility model can effectively improve the thermal protection precision, avoid the condition that the motor is burnt, has better user experience and is convenient to popularize and use.
Furthermore, the utility model adopts the relay for control, and can effectively realize the effective isolation of the power supply.
Meanwhile, the temperature coefficient of the thermistor is about 10 times of that of metal, so that the thermistor has high sensitivity, and the thermal hysteresis coefficient of a temperature sensing element can be very small or very large, so that the temperature measurement application range is wide, and therefore, the thermistor can be used for enabling the measurement precision to be stable within 1 ℃ so as to be suitable for various high-precision occasions.
As shown in fig. 2, a specific embodiment of the rectifying circuit of the present invention:
the rectifier circuit is a bridge rectifier circuit and further comprises a diode, a capacitor CX1 and a capacitor E6;
the diode converts the polarity of the sine wave negative half-wave by utilizing the single-phase conduction characteristic of the diode, so that single-phase pulsating direct current is obtained;
the capacitor CX1 and the capacitor E6 are used for converting single-phase pulsating direct current into relatively stable (relatively small fluctuation) direct current.
As shown in fig. 3, a specific embodiment of the voltage regulating circuit of the present invention:
the voltage regulating circuit further comprises a power switch power supply U2, a direct current voltage stabilizing chip U1, a capacitor C3 and a capacitor C5;
the power switching power supply U2 has a fixed switching frequency of 60HZ and is used for converting the power of 310V direct current into a +12V direct current power supply Ua;
the direct current voltage stabilizing chip U1 is used for stabilizing the +12V direct current power supply Ua into a +5V direct current power supply Ub;
and the capacitor C3 and the capacitor C5 are used for converting the +5V direct-current power supply Ub into a relatively stable 5V direct-current voltage source which is used as a power supply of the voltage acquisition comparison circuit.
As shown in fig. 4, a specific embodiment of the voltage acquisition comparison circuit of the present invention:
the voltage acquisition comparison circuit further comprises a resistor R7, a resistor R11, a resistor R10 and a resistor R9;
the resistor R7, the resistor R11 and the resistor R10 are electrically connected with the anode of the comparator;
the resistor R9 is electrically connected to the negative terminal of the comparator.
The resistor R9 is a variable resistor, the resistance value of the resistor can be changed according to different temperature control requirements, so that the voltage input to the negative electrode of the comparator can be changed, the control result of the relay can be changed, and the protection temperature range can be changed by adjusting the adaptive resistor, so that the utility model has the advantages of wider application range, simple and practical scheme and low manufacturing cost.
One specific embodiment of the thermistor of the present invention:
the resistance value of the thermistor at normal temperature is Rf1, and the resistance value at abnormal high temperature is Rf 2;
20KΩ≤Rf21≤30KΩ；
0.5KΩ≤Rf2≤4KΩ。
the abnormal high temperature is generally 100-160 ℃;
the normal temperature is generally 0 to 50 degrees.
A preferred embodiment of the present invention:
a thermal protection switch is provided, which comprises a thermal protection switch,
the device comprises a voltage acquisition comparison circuit and a switch protection circuit;
the voltage acquisition comparison circuit is provided with a thermistor RT and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor RT34 is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
the positive pole of the comparator is electrically connected with the power supply through a resistor, the negative pole of the comparator is electrically connected with the power supply through a thermistor RT, and the CON port of the comparator is electrically connected with the switch protection circuit;
the switch protection circuit is composed of a triode and a relay and is used for controlling the on-off of a circuit of the equipment to be protected;
the triode is electrically connected with the CON port of the comparator, and can control the on-off action of the relay according to the output voltage of the CON port so as to realize the on-off of the circuit of the equipment to be protected.
The utility model is applied to a specific embodiment of the thermal protection switch:
an electric motor using a thermal protection switch is provided,
comprises the thermal protection switch
The working principle of the utility model is as follows:
as shown in fig. 1, after the input of the local power supply system is processed by the rectifier circuit, the negative half-wave of the alternating current is removed to obtain the positive half-wave alternating current, and then the direct current 5V or 12V power source of the low-voltage circuit is obtained by the voltage regulator circuit.
The voltage acquisition and comparison circuit comprises a thermistor and a common resistor, wherein the thermistor outputs different voltages according to different temperatures when the temperature is higher and the resistance is smaller, and the comparator compares the voltages to select whether the voltage needs to be output or not so as to control the switch protection circuit to realize the automatic thermal protection function.
As shown IN fig. 2, IN _ and IN _ U are respectively connected to two arbitrary three-phase power, and through a bridge rectifier circuit MB6F, and by using the characteristic of single-phase conduction of a diode, the polarity of a sine wave negative half-wave is converted, so that single-phase pulsating direct current is obtained, and through a capacitor CX1 and a capacitor E6, two filter capacitors obtain direct current VDC with relatively small fluctuation, the voltage is 530V, and the direct current is divided by a resistor R4, a resistor R17, a resistor R22, a resistor R25, a resistor R27 and a resistor R29, so that direct current VVDC is obtained.
The VVDC ═ VDC (R25+ R27+ R29)/(R4+ R17+ R22+ R25+ R27+ R29) ≈ 310V.
As shown in fig. 3, the VVDC obtained in fig. 2 is subjected to power conversion by a voltage regulating circuit composed of the transformer TI and the low power switching power supply U2 in fig. 3 through a fixed switching frequency of 60HZ to obtain a +12V dc power supply Ua; then obtaining a +5V direct-current power supply Ub through a direct-current voltage stabilizing chip U1; and then the power supply signal passes through a filter capacitor such as a capacitor C3 and a capacitor C5, and finally, a 5V direct current voltage which is relatively stable and does not fluctuate greatly is obtained and is used as a power supply of a voltage comparison and acquisition circuit.
As shown in fig. 4, the voltage comparison and acquisition circuit further includes a plurality of resistors and a comparator, wherein the positive input end of the comparator is provided with a resistor R7, a resistor R11, and a resistor R10; and a thermistor RT34 and a resistor R9 are arranged at the negative input end.
When the motor normally works, the thermistor is approximately at (Rf1)25K Ω, the negative electrode of the comparator outputs the collected voltage U ═ Ua (R9/(R9+ Rf1)), the positive electrode of the comparator has a voltage U + ═ Ua (R11/(R11+ R7)), and the positive electrode is greater than the negative electrode at about 3.8V, and the comparator output voltage is 5V.
When the motor is abnormally heated, the temperature reaches the warning temperature, the resistance value of the thermistor is reduced to about (Rf2)2K omega, the negative electrode voltage of the comparator is U- ═ Ua (R9/(R9+ Rf2)), 4.1V is detected, the positive electrode voltage is smaller than the negative electrode voltage, and the comparator outputs (Ua)0V voltage.
As shown in fig. 5, there are three sets of structural logics shown in fig. 3, which respectively detect three sets of windings of the three-phase motor, and when any set of windings is over-temperature, the port CON1, the port CON2, and the port CON3 output corresponding models, and three diodes are added at the rear end, so that no conflict occurs after the models, and finally, the models are integrated into the CON port to control the on/off of the circuit.
As shown in fig. 6, a switch protection circuit according to an embodiment of the present invention:
the switch protection circuit mainly comprises an NPN triode Q1 and a relay J4.
When the CON signal of the comparator is 5V, the triode is conducted, the relay is attracted, at the moment, the relay IN _ V-OUT _ V is conducted, the relay IN _ U-OUT _ U is conducted, the three phases of the motor are all IN a conducting state, and at the moment, the motor works normally.
When the motor is abnormally heated, the temperature reaches a warning temperature, the resistance value of any phase of thermistor is reduced to about (Rf2)2K omega, the negative electrode voltage of the voltage comparator is U- ═ Ua (R9/(R9+ Rf2)), 4.1V is detected, the positive electrode voltage is lower than the negative electrode voltage, the comparator outputs (Ua)0V voltage, after the CON receives the 0V voltage, the relay Q3 is released, the IN _ V-OUT _ V and the IN _ U-OUT are disconnected, the three-phase power supply is connected into one phase only and cannot form a loop, the motor stops working, the Back signal is fed Back to the positive electrode of the comparator, the parallel resistance Ra composed of the resistor R10 and the resistor R11 is R10R 11/(R10+ R11), meanwhile, the positive electrode voltage of the voltage comparator is U + ═ Ua (Ra/(Ra + R7)), and the positive electrode voltage is always lower than the negative electrode voltage, the relay cannot be attracted, the motor cannot run, the resistance value of the temperature sensor rises until the temperature of the motor drops again, and after the voltage of the positive pole of the comparator is larger than the voltage of the negative pole, the comparator outputs 5V, and the motor returns to the initial state again.
Besides, the resistors R7, R9, R10 and R11 can use variable resistors, and different resistors are changed according to different temperatures or different types of temperature sensors to change the voltage of the anode of the input voltage comparator and change the control result of the relay.
The above description can realize the thermal protection automatic switch protection.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the utility model without departing from the spirit and scope of the utility model, which is to be covered by the claims.
Claims (10)
1. A thermal protection switch is characterized in that,
the voltage acquisition and comparison circuit comprises a rectification circuit, a voltage regulation circuit, a voltage acquisition and comparison circuit and a switch protection circuit;
the rectifying circuit is provided with at least one filter capacitor and is used for converting an input power supply into direct current and connecting the direct current with the voltage regulating circuit;
the voltage regulating circuit is provided with a transformer and is used for converting the direct current output by the rectifying circuit into a direct current power supply and supplying power to the voltage acquisition and comparison circuit;
the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
one of the positive pole or the negative pole of the comparator is electrically connected with the voltage regulating circuit through a resistor, the other pole of the comparator is electrically connected with the voltage regulating circuit through a thermistor, and the CON port of the comparator is electrically connected with the switch protection circuit;
when the anode voltage of the comparator is larger than the cathode voltage of the comparator, the CON port of the comparator outputs a Ut voltage;
when the anode voltage of the comparator is smaller than the cathode voltage of the comparator, the CON port of the comparator outputs 0V voltage;
the switch protection circuit is provided with a triode and a relay and is used for controlling the on-off of the motor switch circuit;
the triode is electrically connected with the CON port of the comparator and can control the switching action of the relay by utilizing the output voltage of the CON port;
when the comparator outputs the Ut voltage, the triode is conducted, and the relay is closed, so that the motor stops working;
when the comparator outputs 0V voltage, the triode is not conducted, the relay is not attracted, and the triode is in a release state, so that the motor works normally.
2. A thermal protection switch according to claim 1,
the rectifier circuit is a bridge rectifier circuit and further comprises a diode, a capacitor CX1 and a capacitor E6;
the diode converts the polarity of the sine wave negative half-wave by utilizing the single-phase conduction characteristic of the diode, so that single-phase pulsating direct current is obtained;
the capacitor CX1 and the capacitor E6 are used for converting single-phase pulsating direct current into relatively stable direct current.
3. A thermal protection switch according to claim 2,
the voltage regulating circuit further comprises a power switch power supply U2, a direct current voltage stabilizing chip U1, a capacitor C3 and a capacitor C5;
the power switching power supply U2 has a fixed switching frequency of 60HZ and is used for converting the power of 310V direct current into a +12V direct current power supply Ua;
the direct current voltage stabilizing chip U1 is used for stabilizing the +12V direct current power supply Ua into a +5V direct current power supply Ub;
and the capacitor C3 and the capacitor C5 are used for converting the +5V direct-current power supply Ub into a relatively stable 5V direct-current voltage source which is used as a power supply of the voltage acquisition comparison circuit.
4. A thermal protection switch according to claim 1,
the voltage acquisition comparison circuit further comprises a resistor R7, a resistor R11, a resistor R10 and a resistor R9;
the resistor R7, the resistor R11 and the resistor R10 are electrically connected with the anode of the comparator;
the resistor R9 is electrically connected to the negative terminal of the comparator.
5. A thermal protection switch according to claim 4,
the resistor R9 is a resistance change resistor, and the resistance value of the resistor can be changed according to different temperature control requirements.
6. A thermal protection switch according to any one of claims 1 to 5,
the resistance value of the thermistor at normal temperature is Rf1, and the resistance value at abnormal high temperature is Rf 2;
20KΩ≤Rf21≤30KΩ；
0.5KΩ≤Rf2≤4KΩ。
7. a thermal protection switch according to claim 6,
the triode is an NPN triode Q3;
the relay is a double-open double-switch relay.
8. A thermal protection switch according to claim 7,
and Ut is greater than 0, and the value of Ut is equal to the output voltage of the voltage regulating circuit.
9. A thermal protection switch is characterized in that,
the device comprises a voltage acquisition comparison circuit and a switch protection circuit;
the voltage acquisition comparison circuit is provided with a thermistor and a comparator and can output corresponding voltage to the switch protection circuit according to temperature change;
the thermistor is used for converting the external temperature change into the internal resistance value change and is electrically connected with the comparator;
one of the anode or the cathode of the comparator is electrically connected with a power supply through a resistor, the other electrode of the comparator is electrically connected with the power supply through a thermistor RT, and a CON port of the comparator is electrically connected with a switch protection circuit;
the switch protection circuit is provided with a relay and is used for controlling the on-off of a circuit of the equipment to be protected;
the relay is electrically connected with the port of the comparator CON, and the output voltage of the port of the comparator CON is utilized to control the on-off action of the relay so as to realize the on-off of the circuit of the equipment to be protected.
10. An electric machine applying a thermal protection switch is characterized in that,
comprising a thermal protection switch according to any one of claims 1-9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122638339.2U CN216056308U (en) | 2021-10-28 | 2021-10-28 | Thermal protection switch and motor using same |
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|---|---|---|---|
| CN202122638339.2U CN216056308U (en) | 2021-10-28 | 2021-10-28 | Thermal protection switch and motor using same |
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| CN216056308U true CN216056308U (en) | 2022-03-15 |
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2021
- 2021-10-28 CN CN202122638339.2U patent/CN216056308U/en active Active
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