CN212649090U - Protective circuit - Google Patents
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- CN212649090U CN212649090U CN202020637459.3U CN202020637459U CN212649090U CN 212649090 U CN212649090 U CN 212649090U CN 202020637459 U CN202020637459 U CN 202020637459U CN 212649090 U CN212649090 U CN 212649090U
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Abstract
The utility model provides a protection circuit, which comprises a self-recovery protection circuit, a switch circuit, a protection circuit power supply circuit, a protection signal generating circuit and a protection circuit; the end of the direct-current power supply or the direct-current bus V1 is connected with the end of the direct-current power supply or the direct-current bus V2 through a switch circuit, one end of the self-recovery protection circuit is connected with one end of the switch circuit, one end of the self-recovery protection circuit is connected with the other end of the switch circuit, and the switch circuit is connected with the protection circuit; the protection circuit power supply circuit and the protection signal generating circuit are respectively connected with the end of a direct current power supply or a direct current bus V1 and the end of a direct current power supply or a direct current bus V2, and the protection circuit power supply circuit is connected with the protection circuit after being connected with the protection signal generating circuit. Adopt the technical scheme of the utility model, have short-circuit protection function, when the short circuit, the circuit all can be broken off to after the trouble shooting, but the circuit power supply automatic recovery has improved the reliability of system, reduces the maintenance cost.
Description
Technical Field
The utility model belongs to the technical field of the circuit, especially, relate to a protection circuit.
Background
In ac and dc power supply equipment, power section modularization is becoming a mainstream. In the modular device, a mutual redundancy design of the auxiliary power supply is often adopted, and in the design, when the auxiliary power supply of the module is normal, the auxiliary power supply of the module needs to supply power to the direct current bus, and when the auxiliary power supply of the module fails, the auxiliary power supply of the module needs to take power from the direct current bus. Therefore, the reliability of the direct current bus directly affects the reliability of the whole system, so that the direct current power supply circuit with the short-circuit protection function is necessary, and in the prior art, the direct current bus with the short-circuit protection function has low reliability, cannot be automatically recovered after the fault is eliminated, and has high maintenance cost.
SUMMERY OF THE UTILITY MODEL
To above technical problem, the utility model discloses a protection circuit has short-circuit protection function, and the reliability is higher.
To this end, the utility model discloses a technical scheme do:
a protection circuit comprises a self-recovery protection circuit, a switch circuit, a protection circuit power supply circuit, a protection signal generation circuit and a protection circuit; the end of the direct-current power supply or the direct-current bus V1 is connected with the end of the direct-current power supply or the direct-current bus V2 through a switch circuit, one end of the self-recovery protection circuit is connected with one end of the switch circuit, one end of the self-recovery protection circuit is connected with the other end of the switch circuit, and the switch circuit is connected with the protection circuit;
the protection circuit power supply circuit and the protection signal generating circuit are respectively connected with the end of a direct current power supply or a direct current bus V1 and the end of a direct current power supply or a direct current bus V2, and the protection circuit power supply circuit is connected with the protection circuit after being connected with the protection signal generating circuit.
Wherein, V1 and V2 are DC power supplies or DC buses. By adopting the technical scheme, various unidirectional/bidirectional short-circuit protection can be realized as required, and when the short-circuit fault is eliminated, the power supply of the circuit can be automatically recovered, so that the reliability of the system is improved, and the use is more convenient.
As a further improvement of the present invention, the self-recovery protection circuit includes a self-recovery thermistor RT.
As a further improvement of the present invention, the one end of the self-recovery thermistor RT is connected to the one end of the switch circuit, and the other end of the self-recovery thermistor RT is connected to the other end of the switch circuit, the dc power supply or the dc bus V2.
As a further improvement of the present invention, the protection circuit power supply circuit includes a diode D2 and a resistor R2 connected to a common cathode/anode terminal or two cathodes/anodes, and the protection signal generating circuit includes a diode D3 connected to a common anode/cathode terminal or two anodes/cathodes;
an anode/cathode end of the diode D2, an anode/cathode end of the diode D3 and the other end of the self-recovery thermistor RT, a direct current power supply or a direct current bus V2 end are connected, another anode/cathode end of the diode D2, another anode/cathode end of the diode D3 and a direct current power supply or a direct current bus V1 end are connected, a common anode/cathode end of the diode D2 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with a common anode/cathode end of the diode D3 and a protection circuit.
As a further improvement of the present invention, the protection circuit includes a voltage regulator tube Z1, a resistor R1, a resistor R3 and a transistor Q3, the other end of the resistor R2 is connected with the cathode/anode end of the voltage regulator tube Z1, the anode/cathode end of the voltage regulator tube Z1 is connected with the B pole of the transistor Q3 and one end of the resistor R3, the E pole of the transistor Q3 and the other end of the resistor R3 are grounded, and the C pole of the transistor Q3 is connected with the switch circuit through the resistor R1.
As a further improvement of the present invention, the switch circuit includes a single-pole double-throw relay RLY, an input end of the single-pole double-throw relay RLY is connected with a direct-current power supply or a direct-current bus V1 end, a normally closed contact of the single-pole double-throw relay RLY is connected with one end of a self-recovery thermistor RT, and a normally open contact of the single-pole double-throw relay RLY is connected with the other end of the self-recovery thermistor RT, the direct-current power supply or a direct-current bus V2 end;
one end of the pull-in coil of the single-pole double-throw relay RLY is connected with the common cathode/anode end of the diode D2 and one end of the resistor R2, and the resistor R1 is connected with the other end of the pull-in coil of the single-pole double-throw relay RLY.
As a further improvement of the present invention, the protection circuit includes a diode D1 connected to the common cathode/anode terminal or the two cathodes/anodes, the resistor R1 is connected to the common cathode/anode terminal of the diode D1, and the two anode/cathode terminals of the diode D1 are connected to the switch circuit.
As a further improvement of the present invention, the switch circuit includes a transistor Q1, a transistor Q2, a resistor R4 and a resistor R5, the S-pole of the transistor Q2 is connected to the dc power supply or the dc bus V1 and the self-recovery thermistor RT, and the two ends of the resistor R4 are connected to the S-pole of the transistor Q2 and the G-pole of the transistor Q2 respectively; the D pole of the transistor Q2 is connected with the D pole of the transistor Q1, the S pole of the transistor Q1 is connected with the end of a direct current power supply or a direct current bus V2 and the other end of the self-recovery thermistor RT, and the two ends of the resistor R5 are respectively connected with the S pole of the transistor Q1 and the G pole of the transistor Q1;
the G-pole of the transistor Q2 is connected to one anode/cathode terminal of the diode D1, and the other anode/cathode terminal of the diode D1 is connected to the G-pole of the transistor Q1.
As a further improvement of the present invention, the switch circuit includes a transistor Q2, a resistor R4, and a diode D4, the S pole of the transistor Q2 is connected to the dc power supply or the dc bus V1 through a diode D4, the two ends of the resistor R4 are connected to the S pole of the transistor Q2 and the G pole of the transistor Q2, the G pole of the transistor Q2 is connected to the resistor R1, the two ends of the self-recovery thermistor RT are connected to the S pole of the transistor Q2 and the D pole of the transistor Q2, and the D pole of the transistor Q2 is connected to the dc power supply or the dc bus V2;
the other anode/cathode terminal of the diode D2 and the other cathode/anode terminal of the diode D3 are connected to one terminal of the self-recovery thermistor RT, the diode D4, and the S terminal of the transistor Q2.
Compared with the prior art, the beneficial effects of the utility model are that:
adopt the technical scheme of the utility model, direct current bus's reliability is high, has short-circuit protection function, and when DC power supply or direct current bus short circuit, the circuit all can break off to after short-circuit fault eliminated, but the circuit power supply automatic recovery has improved the reliability of system, reduces the maintenance cost.
Drawings
Fig. 1 is a circuit diagram of a protection circuit according to embodiment 1 of the present invention.
Fig. 2 is a circuit diagram of a protection circuit according to embodiment 2 of the present invention.
Fig. 3 is a circuit diagram of a protection circuit according to embodiment 3 of the present invention.
Fig. 4 is a circuit diagram of a protection circuit according to embodiment 4 of the present invention.
Fig. 5 is a circuit diagram of a protection circuit according to embodiment 5 of the present invention.
Fig. 6 is a circuit diagram of a protection circuit according to embodiment 6 of the present invention.
Detailed Description
Preferred embodiments of the present invention are described in further detail below.
A protection circuit comprises a self-recovery protection circuit, a switch circuit, a protection circuit power supply circuit, a protection signal generation circuit and a protection circuit; the end of the direct-current power supply or the direct-current bus V1 is connected with the end of the direct-current power supply or the direct-current bus V2 through a switch circuit, one end of the self-recovery protection circuit is connected with one end of the switch circuit, one end of the self-recovery protection circuit is connected with the other end of the switch circuit, and the switch circuit is connected with the protection circuit; the protection circuit power supply circuit and the protection signal generating circuit are respectively connected with the end of a direct current power supply or a direct current bus V1 and the end of a direct current power supply or a direct current bus V2, and the protection circuit power supply circuit is connected with the protection circuit after being connected with the protection signal generating circuit. The following description is given with reference to preferred embodiments.
Example 1
As shown in fig. 1, the self-recovery protection circuit comprises a self-recovery thermistor RT1, the protection circuit power supply circuit comprises a diode D2 and a resistor R2 which are connected at a common cathode terminal or two cathodes, and the protection signal generation circuit comprises a diode D3 which is connected at a common anode terminal or two anodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3 and a triode Q3, and the switching circuit comprises a single-pole double-throw relay RLY 1.
The input end of the single-pole double-throw relay RLY1 is connected with a direct-current power supply or a direct-current bus V1 end, the normally closed contact of the single-pole double-throw relay RLY1 is connected with one end of a self-recovery thermistor RT, and the normally open contact of the single-pole double-throw relay RLY1 is connected with the other end of the self-recovery thermistor RT and the direct-current power supply or the direct-current bus V2 end; one end of a pull-in coil of the single-pole double-throw relay RLY1 is connected with the common cathode end of the diode D2 and one end of the resistor R2, and the other end of the pull-in coil of the single-pole double-throw relay RLY1 is connected with one end of the resistor R1.
An anode end of the diode D2 and a cathode end of the diode D3 are connected with the other end of the self-recovery thermistor RT and a direct-current power supply or direct-current bus V2 end, the other anode end of the diode D2 and the other cathode end of the diode D3 are connected with the direct-current power supply or direct-current bus V1 end, a common cathode end of the diode D2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with a common anode end of the diode D3 and a cathode end of the voltage-regulator tube Z1, an anode end of the voltage-regulator tube Z1 is connected with a B pole of the triode Q3 and one end of the resistor R3, an E pole of the triode Q3 and the other end of the resistor R3 are grounded, and a C pole of the triode Q3 is connected with the other end of the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are positive, and the power supply direction is bidirectional power supply; the transistor Q3 is an NPN transistor. In the circuit, the self-recovery thermistor RT1 supplies energy to the single-pole double-throw relay RLY1 when the single-pole double-throw relay RLY1 controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit supplies a driving power supply V3 to the protection circuit and supplies power to the relay, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes bidirectional short-circuit protection.
Example 2
As shown in fig. 2, the self-recovery protection circuit comprises a self-recovery thermistor RT1, the protection circuit power supply circuit comprises a diode D2 and a resistor R2 which are connected at a common anode terminal or two anodes, and the protection signal generation circuit comprises a diode D3 which is connected at a common cathode terminal or two cathodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3 and a triode Q3, and the switching circuit comprises a single-pole double-throw relay RLY 1.
The input end of the single-pole double-throw relay RLY1 is connected with a direct-current power supply or a direct-current bus V1 end, the normally closed contact of the single-pole double-throw relay RLY1 is connected with one end of a self-recovery thermistor RT, and the normally open contact of the single-pole double-throw relay RLY1 is connected with the other end of the self-recovery thermistor RT and the direct-current power supply or the direct-current bus V2 end; one end of a pull-in coil of the single-pole double-throw relay RLY1 is connected with a common anode end of a diode D2 and one end of a resistor R2, and the other end of the pull-in coil of the single-pole double-throw relay RLY1 is connected with one end of a resistor R1.
A cathode end of the diode D2 and an anode end of the diode D3 are connected with the other end of the self-recovery thermistor RT and a dc power supply or dc bus V2 end, the other cathode end of the diode D2 and the other anode end of the diode D3 are connected with the dc power supply or dc bus V1 end, a common anode end of the diode D2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with a common cathode end of the diode D3 and an anode of the voltage regulator tube Z1, a cathode of the voltage regulator tube Z1 is connected with a B electrode of the triode Q3 and one end of the resistor R3, an E electrode of the triode Q3 and the other end of the resistor R3 are grounded, and a C electrode of the triode Q3 is connected with the other end of the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are negative, and the power supply direction is bidirectional power supply; the transistor Q3 is a PNP transistor. In the circuit, the self-recovery thermistor RT1 provides energy for the single-pole double-throw relay RLY1 when the single-pole double-throw relay RLY1 controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit provides a driving power supply V3 for the protection circuit and provides power for the single-pole double-throw relay RLY1, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes bidirectional short-circuit protection.
In the protection circuits of embodiments 1 and 2, when the absolute values of V1 and V2 are both greater than the absolute value of the protection voltage (the absolute value of the dc power supply voltage triggering the operation of the protection circuit), V3 is greater than the absolute value of the protection voltage, no protection signal is generated at V4, Z1 is turned on, Q3 is turned on, and RLY1 is turned on. When the absolute value of V1 or V2 is smaller than the absolute value of the protection voltage, V4 generates a protection signal, Z1 is turned off, Q3 is turned off, RLY1 is turned off, current flows through RT1, and RT1 is turned off when RT1 is over-current. When the short-circuit fault is eliminated, RT1 is automatically turned on, and the power supply of the circuit can be automatically recovered.
Example 3
As shown in fig. 3, the self-recovery protection circuit includes a self-recovery thermistor RT 1; the protection circuit power supply circuit comprises a diode D2 and a resistor R2, wherein the diode D2 and the resistor R2 are connected at a common cathode end or two cathodes, and the protection signal generating circuit comprises a diode D3, wherein the diode D3 is connected at a common anode end or two anodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3, a triode Q3 and a diode D1 connected with a common cathode end or two cathodes, and the switching circuit comprises a transistor Q1, a transistor Q2, a resistor R4 and a resistor R5.
The S pole of the transistor Q2 is connected with the end of a direct current power supply or a direct current bus V1 and one end of a self-recovery thermistor RT1, and the two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2; the D pole of the transistor Q2 is connected with the D pole of the transistor Q1, the S pole of the transistor Q1 is connected with the end of a direct current power supply or a direct current bus V2 and the other end of the self-recovery thermistor RT1, and the two ends of the resistor R5 are respectively connected with the S pole of the transistor Q1 and the G pole of the transistor Q1; the G-pole of the transistor Q2 is connected to an anode terminal of the diode D1, and the other anode terminal of the diode D1 is connected to the G-pole of the transistor Q1.
An anode end of the diode D2 and a cathode end of the diode D3 are connected with the other end of the self-recovery thermistor RT1 and a dc power supply or dc bus V2 end, the other anode end of the diode D2 and the other cathode end of the diode D3 are connected with the dc power supply or dc bus V1 end, the common cathode end of the diode D2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with the common anode end of the diode D3 and the cathode of the stabilivolt Z1, the anode of the stabilivolt Z1 is connected with the B pole of the triode Q3 and one end of the resistor R3, the E pole of the triode Q3 and the other end of the resistor R3 are grounded, and the C pole of the triode Q3 is connected with the common cathode end of the diode D1 through the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are positive, and the power supply direction is bidirectional power supply; the transistor Q3 is an NPN transistor, and the transistor Q1 and the transistor Q2 are P-channel transistors. In the circuit, the self-recovery thermistor RT1 supplies energy to the switching tube when the switching tube is turned off, the switching circuit controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit supplies a driving power supply V3 to the protection circuit, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes bidirectional short-circuit protection.
Example 4
As shown in fig. 4, the self-recovery protection circuit includes a self-recovery thermistor RT 1; the protection circuit power supply circuit comprises a diode D2 and a resistor R2, wherein the diode D2 and the resistor R2 are connected at a common anode end or two anodes, and the protection signal generating circuit comprises a diode D3, wherein the diode D3 is connected at a common cathode end or two cathodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3, a triode Q3 and a diode D1 connected with a common anode end or two anodes, and the switching circuit comprises a transistor Q1, a transistor Q2, a resistor R4 and a resistor R5.
The S pole of the transistor Q2 is connected with the end of a direct current power supply or a direct current bus V1 and one end of a self-recovery thermistor RT1, and the two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2; the D pole of the transistor Q2 is connected with the D pole of the transistor Q1, the S pole of the transistor Q1 is connected with the end of a direct current power supply or a direct current bus V2 and the other end of the self-recovery thermistor RT1, and the two ends of the resistor R5 are respectively connected with the S pole of the transistor Q1 and the G pole of the transistor Q1; the G-pole of the transistor Q2 is connected to a cathode terminal of the diode D1, and the other cathode terminal of the diode D1 is connected to the G-pole of the transistor Q1.
One cathode end of the diode D2 and one anode end of the diode D3 are connected to the other end of the self-recovery thermistor RT1 and the end of the dc power supply or the dc bus V2, the other cathode end of the diode D2 and the other anode end of the diode D3 are connected to the end of the dc power supply or the dc bus V1, the common anode end of the diode D2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the common cathode end of the diode D3 and the anode of the regulator tube Z1, the cathode of the regulator tube Z1 is connected to the B electrode of the triode Q3 and one end of the resistor R3, the E electrode of the triode Q3 and the other end of the resistor R3 are grounded, and the C electrode of the triode Q3 is connected to the common anode end of the diode D1 through the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are negative, and the power supply direction is bidirectional power supply; the transistor Q3 is a PNP transistor, and the transistor Q1 and the transistor Q2 are N-channel transistors. In the circuit, the self-recovery thermistor RT1 supplies energy to the switching tube when the switching tube is turned off, the switching circuit controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit supplies a driving power supply V3 to the protection circuit, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes bidirectional short-circuit protection.
Example 5
As shown in fig. 5, the self-recovery protection circuit includes a self-recovery thermistor RT 1; the protection circuit power supply circuit comprises a diode D2 and a resistor R2, wherein the diode D2 and the resistor R2 are connected at a common cathode end or two cathodes, and the protection signal generating circuit comprises a diode D3, wherein the diode D3 is connected at a common anode end or two anodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3 and a triode Q3, and the switching circuit comprises a transistor Q2, a resistor R4 and a diode D4.
The S pole of the transistor Q2 is connected with the cathode of the diode D4, the anode of the diode D4 is connected with the end of a direct current power supply or a direct current bus V1, two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2, the G pole of the transistor Q2 is connected with the resistor R1, two ends of the self-recovery thermistor RT are respectively connected with the S pole of the transistor Q2 and the D pole of the transistor Q2, and the D pole of the transistor Q2 is connected with the end of the direct current power supply or the direct current bus V2.
An anode end of the diode D2 and a cathode end of the diode D3 are connected with a self-recovery thermistor RT1 and a dc power supply or dc bus V2 end, the other anode end of the diode D2 and the other cathode end of the diode D3 are connected with a dc power supply or dc bus V1 end, a common cathode end of the diode D2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with a common anode end of the diode D3 and a cathode of the regulator tube Z1, an anode of the regulator tube Z1 is connected with a B electrode of the triode Q3 and one end of the resistor R3, an E electrode of the triode Q3 and the other end of the resistor R3 are grounded, and a C electrode of the triode Q3 is connected with a G electrode of the transistor Q2 through the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are positive, and the power supply direction is unidirectional; the transistor Q3 is an NPN transistor, the transistor Q1 and the transistor Q2 are P-channel transistors, and the diode D4 is a power diode. In the circuit, the self-recovery thermistor RT1 supplies energy to the switching tube when the switching tube is turned off, the switching circuit controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit supplies a driving power supply V3 to the protection circuit, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes unidirectional short-circuit protection.
Example 6
As shown in fig. 6, the self-recovery protection circuit includes a self-recovery thermistor RT 1; the protection circuit power supply circuit comprises a diode D2 and a resistor R2, wherein the diode D2 and the resistor R2 are connected at a common anode end or two anodes, and the protection signal generating circuit comprises a diode D3, wherein the diode D3 is connected at a common cathode end or two cathodes; the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3 and a triode Q3, and the switching circuit comprises a transistor Q2, a resistor R4 and a diode D4.
The S pole of the transistor Q2 is connected with the anode of the diode D4, the cathode of the diode D4 is connected with the end of a direct current power supply or a direct current bus V1, two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2, the G pole of the transistor Q2 is connected with the resistor R1, two ends of the self-recovery thermistor RT are respectively connected with the S pole of the transistor Q2 and the D pole of the transistor Q2, and the D pole of the transistor Q2 is connected with the end of the direct current power supply or the direct current bus V2.
One cathode end of the diode D2 and one anode end of the diode D3 are connected with a self-recovery thermistor RT1 and a direct-current power supply or direct-current bus V2 end, the other cathode end of the diode D2 and the other anode end of the diode D3 are connected with a direct-current power supply or a direct-current bus V1 end, a common anode end of the diode D2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with the common cathode end of the diode D3 and an anode of the voltage-stabilizing tube Z1, a cathode of the voltage-stabilizing tube Z1 is connected with a B pole of the triode Q3 and one end of the resistor R3, an E pole of the triode Q3 and the other end of the resistor R3 are grounded, and a C pole of the triode Q3 is connected with a G pole of the transistor Q2 through the resistor R1.
The polarity of the power supply at the end of the direct current power supply or the direct current bus V1 and the polarity of the power supply at the end of the direct current power supply or the direct current bus V2 are negative, and the power supply direction is unidirectional; the transistor Q3 is a PNP transistor, the transistor Q1 and the transistor Q2 are N-channel transistors, and the diode D4 is a power diode. In the circuit, the self-recovery thermistor RT1 supplies energy to the switching tube when the switching tube is turned off, the switching circuit controls the connection and disconnection between the V1 and the V2, the protection circuit power supply circuit supplies a driving power supply V3 to the protection circuit, the protection signal generating circuit generates a protection signal V4, the protection circuit controls the action of the switching tube by using the protection signal, and the whole circuit realizes unidirectional short-circuit protection.
In embodiments 3 to 6, when the absolute values of V1 and V2 are both greater than the absolute value of the protection voltage (the absolute value of the dc power supply voltage triggering the protection circuit operation, and the theoretical protection voltage absolute values of the positive power supply and the negative power supply are the same and are described together), V3 is greater than the absolute value of the protection voltage, no protection signal is generated in V4, Z1 is turned on, Q3 is turned on, and Q1 and Q2 are turned on. When the absolute value of V1 or V2 is smaller than the absolute value of the protection voltage, a protection signal is generated at V4, Z1 is turned off, Q3 is turned off, Q1 and Q2 are turned off, current flows through RT1, and when RT1 is over-current, RT1 is turned off. When the fault is removed, RT1 is automatically recovered, and the circuit power supply can be automatically recovered.
The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the utility model belongs to the technical field of ordinary technical personnel, do not deviate from the utility model discloses under the prerequisite of design, can also make a plurality of simple deductions or replacement, all should regard as belonging to the utility model discloses a protection scope.
Claims (9)
1. A protection circuit, characterized by: the self-recovery protection circuit comprises a self-recovery protection circuit, a switching circuit, a protection circuit power supply circuit, a protection signal generation circuit and a protection circuit;
the end of the direct-current power supply or the direct-current bus V1 is connected with the end of the direct-current power supply or the direct-current bus V2 through a switch circuit, one end of the self-recovery protection circuit is connected with one end of the switch circuit, one end of the self-recovery protection circuit is connected with the other end of the switch circuit, and the switch circuit is connected with the protection circuit;
the protection circuit power supply circuit and the protection signal generating circuit are respectively connected with the end of a direct current power supply or a direct current bus V1 and the end of a direct current power supply or a direct current bus V2, and the protection circuit power supply circuit is connected with the protection circuit after being connected with the protection signal generating circuit.
2. The protection circuit of claim 1, wherein: the self-recovery protection circuit comprises a self-recovery thermistor RT.
3. The protection circuit of claim 2, wherein: one end of the self-recovery thermistor RT is connected with one end of the switch circuit, and the other end of the self-recovery thermistor RT is connected with the other end of the switch circuit and the end of the direct-current power supply or the direct-current bus V2.
4. The protection circuit of claim 3, wherein: the protection circuit power supply circuit comprises a diode D2 and a resistor R2, wherein the diode D2 is connected with a common cathode/anode terminal or two cathodes/anodes, and the protection signal generating circuit comprises a diode D3 which is connected with a common anode/cathode terminal or two anodes/cathodes;
an anode/cathode end of the diode D2, an anode/cathode end of the diode D3 and the other end of the self-recovery thermistor RT, a direct current power supply or a direct current bus V2 end are connected, another anode/cathode end of the diode D2, another anode/cathode end of the diode D3 and a direct current power supply or a direct current bus V1 end are connected, a common anode/cathode end of the diode D2 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected with a common anode/cathode end of the diode D3 and a protection circuit.
5. The protection circuit of claim 4, wherein: the protection circuit comprises a voltage regulator tube Z1, a resistor R1, a resistor R3 and a triode Q3, wherein the other end of the resistor R2 is connected with the cathode/anode end of the voltage regulator tube Z1, the anode/cathode end of the voltage regulator tube Z1 is connected with the B pole of the triode Q3 and one end of the resistor R3, the E pole of the triode Q3 and the other end of the resistor R3 are grounded, and the C pole of the triode Q3 is connected with a switch circuit through the resistor R1.
6. The protection circuit of claim 5, wherein: the switch circuit comprises a single-pole double-throw relay RLY, the input end of the single-pole double-throw relay RLY is connected with a direct-current power supply or a direct-current bus V1 end, a normally closed contact of the single-pole double-throw relay RLY is connected with one end of a self-recovery thermistor RT, and a normally open contact of the single-pole double-throw relay RLY is connected with the other end of the self-recovery thermistor RT and the direct-current power supply or direct-current bus V2 end;
one end of the pull-in coil of the single-pole double-throw relay RLY is connected with the common cathode/anode end of the diode D2 and one end of the resistor R2, and the resistor R1 is connected with the other end of the pull-in coil of the single-pole double-throw relay RLY.
7. The protection circuit of claim 5, wherein: the protection circuit comprises a diode D1 with a common cathode/anode terminal or two cathode/anode terminals connected, the resistor R1 is connected with the common cathode/anode terminal of the diode D1, and the two anode/cathode terminals of the diode D1 are connected with the switch circuit.
8. The protection circuit of claim 7, wherein: the switching circuit comprises a transistor Q1, a transistor Q2, a resistor R4 and a resistor R5, wherein the S pole of the transistor Q2 is connected with the end of a direct-current power supply or a direct-current bus V1 and one end of a self-recovery thermistor RT, and the two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2; the D pole of the transistor Q2 is connected with the D pole of the transistor Q1, the S pole of the transistor Q1 is connected with the end of a direct current power supply or a direct current bus V2 and the other end of the self-recovery thermistor RT, and the two ends of the resistor R5 are respectively connected with the S pole of the transistor Q1 and the G pole of the transistor Q1;
the G-pole of the transistor Q2 is connected to one anode/cathode terminal of the diode D1, and the other anode/cathode terminal of the diode D1 is connected to the G-pole of the transistor Q1.
9. The protection circuit of claim 5, wherein: the switch circuit comprises a transistor Q2, a resistor R4 and a diode D4, wherein the S pole of the transistor Q2 is connected with the end of a direct current power supply or a direct current bus V1 through a diode D4, the two ends of the resistor R4 are respectively connected with the S pole of the transistor Q2 and the G pole of the transistor Q2, the G pole of the transistor Q2 is connected with the resistor R1, the two ends of the self-recovery thermistor RT are respectively connected with the S pole of the transistor Q2 and the D pole of the transistor Q2, and the D pole of the transistor Q2 is connected with the end of the direct current power supply or the direct current bus V2;
the other anode/cathode terminal of the diode D2 and the other cathode/anode terminal of the diode D3 are connected to one terminal of the self-recovery thermistor RT, the diode D4, and the S terminal of the transistor Q2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020637459.3U CN212649090U (en) | 2020-04-24 | 2020-04-24 | Protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020637459.3U CN212649090U (en) | 2020-04-24 | 2020-04-24 | Protective circuit |
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| Publication Number | Publication Date |
|---|---|
| CN212649090U true CN212649090U (en) | 2021-03-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020637459.3U Active CN212649090U (en) | 2020-04-24 | 2020-04-24 | Protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212649090U (en) |
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- 2020-04-24 CN CN202020637459.3U patent/CN212649090U/en active Active
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