CN219322274U - Protection circuit, motor control device and lighting equipment - Google Patents
Protection circuit, motor control device and lighting equipment Download PDFInfo
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- CN219322274U CN219322274U CN202223361971.8U CN202223361971U CN219322274U CN 219322274 U CN219322274 U CN 219322274U CN 202223361971 U CN202223361971 U CN 202223361971U CN 219322274 U CN219322274 U CN 219322274U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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Abstract
The application discloses protection circuit, motor control device and lighting apparatus relates to the power technology field. The protection circuit is provided with a first current limiting circuit and is used for controlling the current of the load to be gradually increased under the condition of the output voltage of the power supply, so that the voltage of the load is gradually increased along with the time, and the first switch circuit connected in parallel with the first current limiting circuit is controlled to be conducted until the voltage of the load is larger than or equal to a first threshold value, so that the slow start of the load is realized. And when the power supply stops outputting the voltage, if the voltage of the load is greater than or equal to a second threshold value, controlling the second switch circuit to be conducted so as to absorb the back electromotive force on the load. By using the protection circuit, the problem that the power supply is unstable due to the current pulling and the counter electromotive force at the moment of power on and power off can be solved.
Description
Technical Field
The application belongs to the technical field of power, and particularly relates to a protection circuit, a motor control device and lighting equipment.
Background
The power supply may provide the load with its required operating voltage. At the instant of power on (output voltage), a large pull-up current is generated between the power supply and the load. If the load is an inductive load, at the instant the power supply is turned off (stopping the output voltage), the load will generate a large back emf. The pull current and back emf can cause instability in the power supply.
For this reason, a protection circuit is needed to alleviate the problem that the pull current and the back electromotive force cause the power supply to be unstable at the moment of power on and off.
Disclosure of Invention
The application provides a protection circuit, motor control device and lighting apparatus, aims at alleviating at power on and off instant, draws current and back electromotive force to lead to the unstable problem of power supply.
A first aspect of an embodiment of the present application provides a protection circuit, including:
a first switching circuit configured to connect a power supply and a load;
a second switching circuit configured to connect the load and ground;
a first current limiting circuit configured to connect the power supply, the load, and the first switching circuit for controlling a current of the load to gradually increase in a case of an output voltage of the power supply;
the switch control circuit is connected with the first switch circuit, the second switch circuit and the load, and is used for controlling the first switch circuit to be conducted to short the first current limiting circuit when the voltage of the load is larger than or equal to a first threshold value and controlling the second switch circuit to be conducted to absorb back electromotive force on the load when the voltage of the load is larger than or equal to a second threshold value, and the second threshold value is larger than the first threshold value.
Optionally, the protection circuit further includes:
and the unidirectional conduction circuit is configured that the anode is connected with a power supply, and the cathode is connected with a load.
Optionally, the first current limiting circuit includes:
the negative temperature coefficient element is configured that two ends are respectively connected with two ends of the first switch circuit, and the resistance value of the negative temperature coefficient element is reduced along with the increase of temperature.
Optionally, the switch control circuit includes:
the first voltage dividing circuit is configured to have one end connected with the anode of the voltage stabilizing diode, the other end grounded, and the voltage dividing node connected with the first switching circuit;
and the voltage stabilizing diode is configured to be connected with a load through a cathode and used for being turned on when the voltage of the load is larger than or equal to a first threshold value so as to trigger the first switching circuit to be turned on and being turned off when the voltage of the load is smaller than the first threshold value.
Optionally, the first switching circuit includes:
the first switching tube is configured to have two ends respectively connected with a power supply and a load;
the second voltage dividing circuit is configured to have one end connected with a power supply and the other end connected with one end of the second switching tube, and the voltage dividing node is connected with the first switching tube;
the second switching tube is configured that the other end of the second switching tube is grounded, and the switching control circuit is connected with the second switching tube and used for controlling the second switching tube to be conducted under the condition that the voltage of the load is larger than or equal to a first threshold value so as to trigger the first switching tube to be conducted and controlling the second switching tube to be turned off under the condition that the voltage of the load is smaller than the first threshold value so as to trigger the first switching tube to be turned off.
Optionally, the first switching circuit further comprises:
and the energy storage circuit is configured that one end of the energy storage circuit is connected with a power supply, and the other end of the energy storage circuit is connected with a voltage division node of the second voltage division circuit and the first switching tube and is used for delaying the conduction of the first switching tube under the condition that the voltage of a load is greater than or equal to a first threshold value.
Optionally, the switch control circuit further comprises:
the third voltage dividing circuit is configured to have one end connected with a load and the other end grounded, and the voltage dividing node is connected with the comparison circuit;
the comparison circuit is connected with the second switching circuit and is used for outputting a first control signal for controlling the second switching circuit to be turned on when the voltage of the voltage division node of the third voltage division circuit is larger than the reference voltage and outputting a second control signal for controlling the second switching circuit to be turned off when the voltage of the voltage division node of the third voltage division circuit is smaller than or equal to the reference voltage.
Optionally, the second switching circuit includes:
a third switching tube configured to have one end connected to a load and the other end grounded;
the fourth voltage dividing circuit is configured that one end of the fourth voltage dividing circuit is connected with the switch control circuit, the other end of the fourth voltage dividing circuit is grounded, the voltage dividing node is connected with the third switching tube, the switch control circuit is used for outputting a first control signal for controlling the third switching tube to be conducted under the condition that the voltage of a load is larger than or equal to a second threshold value, and outputting a second control signal for controlling the third switching tube to be turned off under the condition that the voltage of the load is smaller than the second threshold value.
Optionally, the protection circuit further includes:
and the second current limiting circuit is configured to have one end connected with the load and the other end connected with the second switching circuit, or is configured to have one end connected with the second switching circuit and the other end grounded.
A second aspect of an embodiment of the present application provides a power supply device, including a power supply and the protection circuit provided in the first aspect, where the protection circuit is configured to connect the power supply and a load.
A third aspect of an embodiment of the present application provides a motor control device including a motor and the protection circuit provided in the first aspect, where the load includes the motor.
A fourth aspect of the embodiments of the present application provides a lighting device, including a motor, a lighting lamp, and a protection circuit provided in the first aspect, where the load includes the motor and the lighting lamp, and the motor is connected with the lighting lamp, and is used for driving the lighting lamp to move or rotate.
Compared with the prior art, the embodiment of the application has the beneficial effects that:
at the moment of power on, i.e. under the condition of power output voltage, the first current limiting circuit can control the current of the load to gradually increase, which is equivalent to gradually increasing the voltage on the load. Over time, the voltage of the load is gradually increased until the voltage of the load is greater than or equal to a first threshold value, and the switch control circuit controls the first switch circuit to be turned on from off to be turned on so as to short-circuit the first current limiting circuit, so that slow starting of the load is realized, and the problem that the power supply is unstable due to the pull current generated at the moment of power supply starting can be solved. When the power supply is turned off, that is, when the power supply stops outputting the voltage, if the voltage (for example, back electromotive force) of the load is greater than or equal to the second threshold value, the switch control circuit controls the second switch circuit to be turned on so as to absorb the back electromotive force on the load, and the problem that the back electromotive force generated at the power supply turning off moment causes unstable power supply can be solved.
Drawings
Fig. 1 is a schematic diagram of a first structure of a protection circuit according to an embodiment of the present application;
fig. 2 is a schematic diagram of a second structure of the protection circuit according to the embodiment of the present application;
fig. 3 is a schematic diagram of a third structure of the protection circuit according to the embodiment of the present application.
Illustration of:
10. a first current limiting circuit; 20. a first switching circuit; 21. a second voltage dividing circuit; 22. a tank circuit; 30. a switch control circuit; 31. a first voltage dividing circuit; 32. a third voltage dividing circuit; 40. a second switching circuit; 41. a fourth voltage dividing circuit; 50. a unidirectional conduction circuit; 60. a second current limiting circuit; r0, negative temperature coefficient element; r1, a first resistor; r2, a second resistor; r3, a third resistor; r4, a fourth resistor; r5, a fifth resistor; r6, a sixth resistor; r7, a seventh resistor; r8, eighth resistor; r9, ninth resistor; d1, a first diode; DZ, zener diode; c1, capacitance; q1, a first switching tube; q2, a second switching tube; q3, a third switching tube; A. a comparison circuit; vref, reference voltage.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The power supply may provide the load with its required operating voltage. At the moment of power on, a large pull current is generated between the power supply and the load. If the load is an inductive load, the load will generate a large back emf at the instant the power is turned off. The pull current and back emf can cause instability in the power supply.
In view of this, the embodiments of the present application provide a protection circuit, a power supply device, a motor control device, and a lighting apparatus, which can alleviate the problem that the pull current and the back electromotive force cause the unstable power supply of the power supply at the moment of turning on and off the power supply.
The implementation principle of the embodiment of the application is as follows: by arranging the slow start circuit, the current of the load is gradually increased along with the time at the moment of starting the power supply, so that the slow start of the load is realized, and the problem that the power supply is unstable due to the current pulling is solved. By arranging the absorption circuit, when the power supply is turned off and the voltage of the load is larger than or equal to a preset threshold value, the absorption circuit is conducted and absorbs counter electromotive force on the load, so that the problem that the power supply is unstable due to the counter electromotive force is solved.
In order to illustrate the technical solutions described in the present application, the following description is made by specific examples.
As shown in fig. 1, a schematic configuration diagram of a protection circuit provided in an embodiment of the present application is shown, and for convenience of explanation, only a portion related to the embodiment is shown.
As shown in fig. 1, the protection circuit includes a first switching circuit 20, a second switching circuit 40, a switching control circuit 30, and a first current limiting circuit 10, the first switching circuit 20 is connected to a power source and a load, the second switching circuit 40 is connected to a load and ground, the first current limiting circuit 10 is connected to the power source, the load, and the first switching circuit 20, and the switching control circuit 30 is connected to the first switching circuit 20, the second switching circuit 40, and the load.
The power supply is used for converting input alternating current or direct current into voltage required by a load. When the first switch circuit 20 is turned off, the voltage output by the power supply can be transmitted to the load through the first current limiting circuit 10. At this time, the first current limiting circuit 10 may control the current of the load to gradually increase. In the case where the current of the load gradually increases, the voltage of the load gradually increases. When the first switching circuit 20 is turned on, shorting the first current limiting circuit 10 may be implemented such that the voltage output by the power supply is transmitted to the load through the first switching circuit 20.
In this embodiment, at the initial stage of the power output voltage, the first switch circuit 20 is turned off, and the voltage is transmitted to the load via the first current limiting circuit 10. The first current limiting circuit 10 controls the current of the load to gradually increase so that the voltage of the load gradually increases. When the voltage of the load is greater than or equal to the first threshold, the switch control circuit 30 controls the first switch circuit 20 to be turned on so as to short-circuit the first current limiting circuit 10, thereby realizing slow start of the load and alleviating the problem of unstable power supply caused by the pull current generated at the moment of power on.
In the case where the power supply stops outputting the voltage, the second switching circuit 40 is controlled to be turned on to absorb the back electromotive force on the load if the voltage of the load (for example, the back electromotive force generated by the inductive load) is greater than or equal to the second threshold. It should be understood that, since the second switch circuit 40 is connected to the ground, when the second switch circuit 40 is turned on, the back electromotive force generated on the load can be led to the ground through the second switch circuit 40, so as to achieve the effect of absorbing the back electromotive force, and solve the problem that the back electromotive force generated at the moment of power off causes unstable power supply.
The present embodiment does not specifically limit the type of load. For example, the load includes an inductive load such as an electric fan, a motor, an induction cooker, and a transformer.
The values of the first threshold value and the second threshold value are not particularly limited in this embodiment. For example, according to circuit analysis, the first threshold should be smaller than the output voltage of the power supply, and the second threshold should be larger than the first threshold, so as to avoid conducting the second switching circuit 40 under the condition that the load is operating normally.
The structures of the first current limiting circuit 10, the first switching circuit 20, the second switching circuit 40, and the switching control circuit 30 are not particularly limited in this embodiment, and a skilled person may set as needed.
As an example, in case the voltage of the load is smaller than the first threshold value, the switch control circuit 30 is further configured to control the first switch circuit 20 to be turned off, so that the first current limiting circuit 10 controls the current of the load to gradually increase.
As an example, in case the voltage of the load is smaller than the second threshold value, the switch control circuit 30 is further configured to control the second switch circuit 40 to be turned off so that the load can operate normally.
As shown in fig. 2, as an alternative implementation manner of this embodiment, the protection circuit further includes a unidirectional conduction circuit 50, where an anode of the unidirectional conduction circuit 50 is connected to a power source, and a cathode of the unidirectional conduction circuit is connected to a load. The unidirectional current conducting circuit 50 may limit the direction of current flow through the unidirectional current conducting circuit 50 to avoid current flow from the load to the power source as much as possible.
As shown in fig. 3, in another embodiment of the present application, specific structures of the first current limiting circuit 10, the first switching circuit 20, the second switching circuit 40, the switching control circuit 30, and the unidirectional conductive circuit 50 are disclosed.
As an alternative implementation manner of this embodiment, in the case of the power output voltage, the resistance value of the first current limiting circuit 10 gradually decreases, so as to control the current flowing through the first current limiting circuit 10 to gradually increase, thereby realizing slow start of the load.
As an example, the first current limiting circuit 10 includes an adjustable resistor, both ends of which are connected to both ends of the first switching circuit 20, respectively. The effective resistance of the adjustable resistor is adjusted, so that the resistance of the adjustable resistor is gradually reduced, the current of the load is controlled to be gradually increased, and the slow start of the load is realized. Alternatively, in the case of the power output voltage, the effective resistance value of the adjustable resistor may be manually or automatically adjusted, which is not particularly limited in this embodiment.
As an example, the first current limiting circuit 10 includes a plurality of current limiting resistors and a plurality of switches, each of the current limiting resistors being connected to one of the switches to form one current limiting branch. The current limiting branches are connected in parallel, and two ends of the current limiting branches after being connected in parallel are respectively connected with two ends of the first switch circuit 20. Therefore, under the condition of the power output voltage, the on-off of the switch can be manually or automatically controlled to adjust the effective resistance value of the first current limiting circuit 10. For example, the number of switches turned on is gradually increased, so that the effective resistance of the first current limiting circuit 10 is gradually reduced, and thus the current of the load is controlled to be gradually increased, and slow start of the load is realized.
As an example, the first current limiting circuit 10 includes a negative temperature coefficient element R0, two ends of the negative temperature coefficient element R0 are respectively connected to two ends of the first switch circuit 20, and a resistance value of the negative temperature coefficient element R0 decreases with an increase in temperature. Alternatively, the negative temperature coefficient element R0 is a negative temperature coefficient thermistor, a negative temperature coefficient thermal resistor, or other elements having a negative temperature coefficient characteristic, which is not particularly limited in this embodiment.
As shown in fig. 3, as an alternative implementation of the present embodiment, the unidirectional conduction circuit 50 includes a first diode D1, an anode of the first diode D1 is connected to a power source through the first switching circuit 20, and a cathode of the first diode D1 is connected to a load. With the unidirectional conduction characteristic of the first diode D1, current flow from the load to the power supply can be avoided. Alternatively, the first diode D1 may be a schottky diode, which has advantages of high switching frequency and reduced forward voltage.
As shown in fig. 3, as an alternative implementation of the present embodiment, the switch control circuit 30 includes a first voltage dividing circuit 31 and a zener diode DZ.
The first voltage dividing circuit 31 is configured with one end connected to the anode of the zener diode DZ, the other end grounded, and a voltage dividing node connected to the first switch circuit 20. The zener diode DZ is configured to be cathode-connected to the load for conducting when the voltage of the load is greater than or equal to the first threshold value, to trigger the first switching circuit 20 to conduct, and to trigger the first switching circuit 20 to turn off when the voltage of the load is less than the first threshold value.
It should be appreciated that in the case where the voltage of the load is less than the first threshold, the zener diode DZ may or may not be conductive, but the voltage of the voltage division node of the first voltage division circuit 31 is insufficient to trigger the first switch circuit 20 to be conductive.
Alternatively, the first voltage dividing circuit 31 includes a plurality of resistors, for example, a first resistor R1 and a second resistor R2, and a connection node of the first resistor R1 and the second resistor R2 is a voltage dividing node of the first voltage dividing circuit 31.
As an example, one end of the first resistor R1 is used as a voltage division node and is connected to one end of the first switch circuit 20 and one end of the second resistor R2, the other end of the first resistor R1 is connected to the anode of the zener diode DZ, and the other end of the second resistor R2 is grounded. In this embodiment, the resistances of the first resistor R1 and the second resistor R2 are not specifically limited, and a technician may set the resistances as required.
As shown in fig. 3, as an alternative implementation of the present embodiment, the first switching circuit 20 includes a first switching transistor Q1, a second voltage dividing circuit 21, and a second switching transistor Q2. The first switching tube Q1 is configured to have both ends connected to a power source and a load, respectively. The second voltage dividing circuit 21 is configured to have one end connected to the power supply and the other end connected to one end of the second switching tube Q2, and a voltage dividing node of the second voltage dividing circuit 21 is connected to the first switching tube Q1. The second switching tube Q2 is configured with the other end grounded.
The switch control circuit 30 is connected to the second switching tube Q2, for example, a voltage division node of the first voltage division circuit 31 is connected to the second switching tube Q2. The switch control circuit 30 is configured to control the second switching tube Q2 to be turned on when the voltage of the load is greater than or equal to a first threshold value, so as to trigger the first switching tube Q1 to be turned on, and control the second switching tube Q2 to be turned off when the voltage of the load is less than the first threshold value, so as to trigger the first switching tube Q1 to be turned off.
As one example, the first switching transistor Q1 includes any one of a transistor, a Metal-Oxide-semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), and a solid state relay, and the second switching transistor Q2 includes any one of a transistor, a MOSFET, an IGBT, and a solid state relay. For example, the first switching transistor Q1 includes a P-type MOSFET, and the second switching transistor Q2 includes an NPN transistor.
As an example, the second voltage dividing circuit 21 includes a plurality of resistors, for example, a third resistor R3 and a fourth resistor R4, and a connection node of the third resistor R3 and the fourth resistor R4 is a voltage dividing node of the second voltage dividing circuit 21.
For example, one end of the third resistor R3 is connected to the source and the power supply of the P-type MOSFET, the drain of the P-type MOSFET is connected to the anode of the first diode D1, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the gate of the P-type MOSFET, the other end of the fourth resistor R4 is connected to the collector of the NPN-type triode, the emitter of the NPN-type triode is grounded, and the base of the NPN-type triode is connected to the voltage dividing node of the first voltage dividing circuit 31.
As shown in fig. 3, as an alternative implementation manner of this embodiment, the first switching circuit 20 further includes a tank circuit 22, where the tank circuit 22 is configured to have one end connected to a power source, and the other end connected to a voltage division node of the second voltage division circuit 21 and the first switching tube Q1. For example, the other end of the tank circuit 22 is connected to the other end of the third resistor R3 and the gate of the P-type MOS transistor.
The tank circuit 22 is configured to delay turning on the first switching tube Q1 when the voltage of the load is greater than or equal to the first threshold. The implementation principle is that when the second switching tube Q2 is turned on, the power supply charges the energy storage circuit 22, and then the first switching tube Q1 is turned on until the charging is completed, so as to delay the turning on of the first switching tube Q1.
As an example, the tank circuit 22 includes a first capacitor C1, where one end of the first capacitor C1 is connected to the power supply and the source of the P-type MOSFET, and the other end is connected to the other end of the third resistor R3 and the gate of the P-type MOSFET.
The protection circuit provided in this embodiment can delay the turn-on of the P-type MOSFET through the first capacitor C1, so as to delay the start of the load and reduce the switching noise of the first switching tube Q1. Also, when the stability of the first current limiting circuit 10 is reduced (e.g., the resistance recovery characteristic of the negative temperature coefficient thermistor is deteriorated), the slow start of the load can still be achieved by the first capacitor C1.
As shown in fig. 3, as an alternative implementation of the present embodiment, the switch control circuit 30 further includes a third voltage dividing circuit 32 and a comparison circuit a. The third voltage dividing circuit 32 is configured with one end connected to the load and the other end grounded, and the voltage dividing node of the third voltage dividing circuit 32 is connected to the comparison circuit a. The comparison circuit a is connected to the second switching circuit 40, and is configured to output a first control signal for controlling the second switching circuit 40 to be turned on when the voltage of the voltage division node of the third voltage division circuit 32 is greater than the reference voltage Vref, and to output a second control signal for controlling the second switching circuit 40 to be turned off when the voltage of the voltage division node of the third voltage division circuit 32 is less than or equal to the reference voltage Vref. Alternatively, the first control signal and the second control signal are both level signals, for example, a high level signal and a low level signal, respectively.
Optionally, the third voltage dividing circuit 32 includes a plurality of resistors, for example, a fifth resistor R5 and a sixth resistor R6, and a connection node of the fifth resistor R5 and the sixth resistor R6 is a voltage dividing node of the third voltage dividing circuit 32.
As an example, one end of the fifth resistor R5 is connected to the load and the cathode of the first diode D1, the other end of the fifth resistor R5 is connected to the comparison circuit a and one end of the sixth resistor R6, and the other end of the sixth resistor R6 is grounded.
Optionally, the comparison circuit a comprises an operational amplifier comprising an inverting input, a non-inverting input and an output.
As an example, the inverting input terminal of the operational amplifier is connected to the reference voltage Vref, the non-inverting input terminal is connected to the other end of the fifth resistor R5, and the output terminal is connected to the second switching circuit 40.
The value of the reference voltage Vref and the structure of the operational amplifier are not particularly limited in this embodiment. Optionally, when the voltage of the load is greater than or equal to the second threshold, the voltage of the non-inverting input end of the operational amplifier is greater than the reference voltage Vref, and the operational amplifier outputs a first control signal to trigger the second switch circuit 40 to be turned on; when the voltage of the load is smaller than the second threshold, the voltage of the non-inverting input terminal of the operational amplifier is smaller than or equal to the reference voltage Vref, and the operational amplifier outputs a second control signal to trigger the second switch circuit 40 to turn off.
As shown in fig. 3, as an alternative implementation of the present embodiment, the second switching circuit 40 includes a third switching transistor Q3 and a fourth voltage dividing circuit 41. The third switching tube Q3 is configured to have one end connected to a load and the other end grounded. The fourth voltage dividing circuit 41 is configured with one end connected to the switch control circuit 30, the other end grounded, and the voltage dividing node connected to the third switching tube Q3. For example, an output terminal of the operational amplifier is connected to one terminal of the fourth voltage dividing circuit 41, and is configured to output a first control signal for controlling the third switching transistor Q3 to be turned on when the voltage of the load is greater than or equal to the second threshold value, and to output a second control signal for controlling the third switching transistor Q3 to be turned off when the voltage of the load is less than the second threshold value.
As an example, the fourth voltage dividing circuit 41 includes a plurality of resistors, for example, a seventh resistor R7 and an eighth resistor R8, and a connection node of the seventh resistor R7 and the eighth resistor R8 is a voltage dividing node of the fourth voltage dividing circuit 41.
For example, one end of the seventh resistor R7 is connected to the output end of the operational amplifier, and the other end is connected to one end of the eighth resistor R8 and the third switching tube Q3, and the other end of the eighth resistor R8 is grounded.
As one example, the third switching transistor Q3 includes any one of a triode, a MOSFET, an IGBT, and a solid state relay. Optionally, the third switching tube Q3 comprises an N-type MOSFET. For example, the other end of the seventh resistor R7 is connected to the gate of the N-type MOSFET and one end of the eighth resistor R8, the source of the N-type MOSFET is grounded, and the drain of the N-type MOSFET is connected to the load.
As shown in fig. 3, as an alternative implementation manner of this embodiment, the protection circuit further includes a second current limiting circuit 60, where the second current limiting circuit 60 is configured to have one end connected to the load and the other end connected to the second switching circuit 40. Or the second current limiting circuit 60 is configured with one end connected to the second switching circuit 40 and the other end grounded. The second current limiting circuit 60 is used to avoid excessive current flowing through the second switching circuit 40.
Optionally, the second current limiting resistor includes a ninth resistor R9, where one end of the ninth resistor R9 is connected to the load and the cathode of the first diode D1, and the other end is connected to the drain of the N-type MOSFET.
In another embodiment of the present application, there is also provided a power supply device including a power supply and the protection circuit provided in any of the above embodiments, the protection circuit being configured to connect the power supply and a load.
According to the power supply device provided by the embodiment, the protection circuit is arranged between the output end of the power supply and the load, so that the problem that the power supply is unstable due to the pull current and the counter electromotive force of the load when the power supply is turned on and off can be solved.
In another embodiment of the present application, there is further provided a motor control device, including a motor and the protection circuit provided in any of the above embodiments, the load includes the motor, and the power supply is configured to provide a required operating voltage for the motor.
The motor control device provided by the embodiment can alleviate the problem that the power supply is unstable due to the current pulling and back electromotive force of the motor when the power supply is turned on and off by arranging the protection circuit.
In another embodiment of the present application, there is further provided a lighting device, including a motor, a lighting lamp, and a protection circuit provided in any one of the above embodiments, where the load includes the motor and the lighting lamp, and the motor is connected to the lighting lamp, and is used for driving the lighting lamp to move or rotate. Alternatively, the voltage output by the power supply can be provided for the motor, and also can be provided for the illuminating lamp. Optionally, in some embodiments, the voltage output by the power supply may also be converted into the working voltage required by the lighting lamp by the voltage conversion circuit.
The lighting equipment provided by the embodiment can relieve the problem that the power supply is unstable due to the current and the counter electromotive force of the motor when the power supply is turned on and off by arranging the protection circuit, so that the motor can drive the lighting lamp to stably move or rotate.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (10)
1. A protection circuit, comprising:
a first switching circuit (20) configured to connect a power source and a load;
a second switching circuit (40) configured to connect the load and ground;
-a first current limiting circuit (10) configured to connect the power supply, the load and the first switching circuit (20) for controlling a gradual increase of the current of the load in case of an output voltage of the power supply;
a switch control circuit (30) connected to the first switch circuit (20), the second switch circuit (40) and the load for controlling the first switch circuit (20) to turn on to short the first current limiting circuit (10) if the voltage of the load is greater than or equal to a first threshold value, and for controlling the second switch circuit (40) to turn on to absorb back emf on the load if the voltage of the load is greater than or equal to a second threshold value, the second threshold value being greater than the first threshold value.
2. The protection circuit of claim 1, further comprising: a unidirectional conduction circuit (50) configured to have an anode connected to the power source and a cathode connected to the load;
the first current limiting circuit (10) includes: and a negative temperature coefficient element (R0) configured such that both ends are respectively connected to both ends of the first switch circuit (20), and the resistance value of the negative temperature coefficient element (R0) decreases with an increase in temperature.
3. The protection circuit according to claim 1, wherein the switch control circuit (30) includes:
a first voltage dividing circuit (31) configured to have one end connected to an anode of a zener Diode (DZ) and the other end grounded, and a voltage dividing node connected to the first switching circuit (20);
the zener Diode (DZ) is configured to be connected to the load at a cathode, and is used for being turned on when the voltage of the load is greater than or equal to the first threshold value so as to trigger the first switch circuit (20) to be turned on, and is used for being turned off when the voltage of the load is less than the first threshold value.
4. The protection circuit according to claim 1, wherein the first switching circuit (20) comprises:
a first switching tube (Q1) configured to have both ends connected to the power supply and the load, respectively;
a second voltage dividing circuit (21) configured to have one end connected to the power supply and the other end connected to one end of a second switching tube (Q2), and a voltage dividing node connected to the first switching tube (Q1);
the second switching tube (Q2) is configured that the other end of the second switching tube is grounded, the switch control circuit (30) is connected with the second switching tube (Q2) and used for controlling the second switching tube (Q2) to be conducted under the condition that the voltage of the load is larger than or equal to the first threshold value so as to trigger the first switching tube (Q1) to be conducted, and controlling the second switching tube (Q2) to be turned off under the condition that the voltage of the load is smaller than the first threshold value so as to trigger the first switching tube (Q1) to be turned off.
5. The protection circuit according to claim 4, wherein the first switching circuit (20) further comprises:
and the energy storage circuit (22) is configured to have one end connected with the power supply, and the other end connected with the voltage division node of the second voltage division circuit (21) and the first switch tube (Q1) and is used for delaying the conduction of the first switch tube (Q1) under the condition that the voltage of the load is greater than or equal to the first threshold value.
6. The protection circuit according to claim 1, wherein the switch control circuit (30) further comprises:
a third voltage dividing circuit (32) configured such that one end is connected to the load, the other end is grounded, and a voltage dividing node is connected to the comparing circuit (a);
the comparison circuit (A) is connected with the second switching circuit (40) and is used for outputting a first control signal for controlling the second switching circuit (40) to be turned on when the voltage of the voltage division node of the third voltage division circuit (32) is larger than a reference voltage (Vref) and outputting a second control signal for controlling the second switching circuit (40) to be turned off when the voltage of the voltage division node of the third voltage division circuit (32) is smaller than or equal to the reference voltage (Vref).
7. The protection circuit according to claim 1, wherein the second switching circuit (40) comprises:
a third switching tube (Q3) configured to have one end connected to the load and the other end grounded;
and a fourth voltage dividing circuit (41) configured to have one end connected to the switch control circuit (30), the other end grounded, and a voltage dividing node connected to the third switching tube (Q3), wherein the switch control circuit (30) is configured to output a first control signal for controlling the third switching tube (Q3) to be turned on when the voltage of the load is greater than or equal to the second threshold value, and to output a second control signal for controlling the third switching tube (Q3) to be turned off when the voltage of the load is less than the second threshold value.
8. The protection circuit according to any one of claims 1 to 7, further comprising:
and a second current limiting circuit (60) configured to have one end connected to the load and the other end connected to the second switching circuit (40), or configured to have one end connected to the second switching circuit (40) and the other end grounded.
9. A motor control apparatus comprising a motor and a protection circuit as claimed in any one of claims 1 to 8, the load comprising the motor.
10. A lighting device comprising a motor, a lighting lamp, and the protection circuit of any one of claims 1 to 8, wherein the load comprises the motor and the lighting lamp, and wherein the motor is connected to the lighting lamp for driving the lighting lamp to move or rotate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223361971.8U CN219322274U (en) | 2022-12-13 | 2022-12-13 | Protection circuit, motor control device and lighting equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223361971.8U CN219322274U (en) | 2022-12-13 | 2022-12-13 | Protection circuit, motor control device and lighting equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219322274U true CN219322274U (en) | 2023-07-07 |
Family
ID=87034769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223361971.8U Active CN219322274U (en) | 2022-12-13 | 2022-12-13 | Protection circuit, motor control device and lighting equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219322274U (en) |
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2022
- 2022-12-13 CN CN202223361971.8U patent/CN219322274U/en active Active
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