CN111404124A

CN111404124A - Protection circuit for realizing reverse connection of polar electrolytic capacitor by using NOT gate or AND gate

Info

Publication number: CN111404124A
Application number: CN202010387189.XA
Authority: CN
Inventors: 张运楚; 李全民
Original assignee: Shandong Jianzhu University
Current assignee: Shandong Jianzhu University
Priority date: 2020-05-09
Filing date: 2020-05-09
Publication date: 2020-07-10

Abstract

The invention relates to a protection circuit for realizing reversal connection of a polar electrolytic capacitor by using a NOT gate, which consists of an electrolytic capacitor E1, a terminal JP1, a NOT gate U1A, a NOT gate U1B, a NOT gate U1C, a triode Q1, a relay JDQ1, a light emitting diode L ED1 and a direct current power supply circuit.

Description

Protection circuit for realizing reverse connection of polar electrolytic capacitor by using NOT gate or AND gate

Technical Field

The invention relates to a protection circuit for reverse connection of a polar electrolytic capacitor, in particular to a protection circuit for realizing reverse connection of the polar electrolytic capacitor by using a NOT gate or an AND gate.

Background

The polar electrolytic capacitor is provided with the positive pin and the negative pin, so that the polar electrolytic capacitor cannot be connected in a wrong way when in use, and the damage of the polar electrolytic capacitor can be caused, which is determined by the structure and the composition of the electrolytic capacitor, and the electrolytic capacitor contains an electrolyte material for storing charges, so that the effect of storing the charges cannot be realized and the damage of the polar electrolytic capacitor can be caused if the direction of current applied to the electrolytic capacitor is incorrect.

In the teaching process of electronic experiments, the students in electrical homework can use the electrolytic capacitor in a laboratory, for example, in the teaching process of power supply filtering experiments, the students need to access the electrolytic capacitor by hands so as to deepen the understanding and mastering of the students on the working principle and the working characteristic of the electrolytic capacitor. In the actual experimentation, always have some students to connect the positive negative pole of electrolytic capacitor to the contrary, connect the back of turning over, then lead to the electrolytic capacitor to damage gently, serious still can cause the electrolytic capacitor explosion, the electrolytic capacitor explosion not only can bring frightening and personal safety for the student, can cause even to catch fire and conflagration, therefore, it is important especially to develop a circuit with electrolytic capacitor to turn over the protection, when the electrolytic capacitor appears the reversal, can break off electrolytic capacitor and place circuit, and send alarm signal, in order to remind the wiring mistake, in order to avoid the electrolytic capacitor harm, the explosion and the emergence that causes personal safety and property loss accident. The AND gate and the NOT gate are common devices in digital logic operation, and can realize the detection and alarm of the reverse connection of the polar electrolytic capacitor.

Disclosure of Invention

The present invention provides a protection circuit for realizing reverse connection of a polar electrolytic capacitor by using a not gate or an and gate in order to overcome the defects of the technical problems.

The invention relates to a protection circuit for realizing the reverse connection of a polar electrolytic capacitor by using a NOT gate, which comprises a capacitor terminal JP1, a polar electrolytic capacitor E1 and a capacitor reverse connection protection circuit, wherein the E1 is a polar electrolytic capacitor which is protected and is connected into other circuits, the capacitor terminal JP1 comprises two terminals, and the anode and the cathode of an E1 are connected with a capacitor terminal JP1, and the protection circuit is characterized in that the capacitor reverse connection protection circuit consists of a NOT gate U1A, a NOT gate U1B, a NOT gate U1C, a triode Q1, a relay JDQ1, a light-emitting diode L ED1, a direct current power circuit and diodes D1, D2, D3 and D4, the anode of the polar electrolytic capacitor E1 is connected with one terminal of the capacitor terminal JP1 through the normally open point of the relay JDQ1, the cathode of the E1 is connected with the anode terminal of the capacitor terminal JP1, the cathode of the E1 is connected with the anode of the power circuit and the power input terminal Vcc 72 through the anode of the power supply U72, the negative pole of the NAND gate of the power circuit is connected with the power supply U72, the anode of the power supply and the negative pole of the power supply of the NAND gate of the power supply of the diode of the power supply, the NAND gate U72, the anode of the NAND gate U72, the anode of the NAND gate of the diode is connected with Vcc 72, the power supply 72, the anode of the power;

the output end of the U1A is connected with the input end of the U1B, the output end of the U1B is connected to the base electrode of a triode Q1 through a resistor R6, the Q1 is an NPN type triode, the emitter electrode of the triode Q1 is connected to the ground of a power supply, the collector electrode of the Q1 is connected with a relay JDQ1 in series and then connected to the positive side of the power supply, and the output end of the NOT gate U1C is connected to the positive side of the power supply through the resistor R5 and a light emitting diode L ED1 in.

The invention relates to a protection circuit for realizing the reverse connection of a polar electrolytic capacitor by using a NOT gate, wherein a direct-current power supply circuit consists of a full-bridge rectification circuit formed by a transformer TB1, a three-terminal voltage-stabilizing tube PV1, an electrolytic capacitor E2, an electrolytic capacitor E3 and diodes D6, D7, D8 and D9, a primary side of a transformer TB1 is connected to an alternating-current commercial power supply, a secondary side of the transformer TB1 is connected to the input end of the full-bridge rectification circuit, the anode of the output end of the full-bridge rectification circuit is connected to the input end of the three-terminal voltage-stabilizing tube PV1, and the output; the electrolytic capacitor E3 is arranged at the output end of the full-bridge rectification circuit, and the electrolytic capacitor E2 is arranged at the output end of the three-terminal voltage regulator tube PV 1.

The invention relates to a protection circuit for realizing the reverse connection of a polar electrolytic capacitor by using a NOT gate, wherein two ends of a coil of a relay JDQ1 are connected in parallel with a freewheeling diode D5 for preventing the self-induction voltage generated by the relay JDQ1 from being too high, and the anode of a diode D5 is connected to the collector of a triode Q1 and the anode of a cathode power supply.

The protection circuit for realizing the reverse connection of the polar electrolytic capacitor by using the NOT gate has the advantages that the resistance values of the resistor R1 and the resistor R2 are both 20k omega, the resistance values of the resistor R3 and the resistor R4 are both 100k omega, and the resistance values of the resistor R5 and the resistor R6 are both 4.7k omega.

The invention relates to a protection circuit for realizing the reverse connection of a polarized electrolytic capacitor by an AND gate, which comprises a capacitor terminal JP, a polarized electrolytic capacitor E and a capacitor reverse connection protection circuit, wherein the E is the polarized electrolytic capacitor which is protected and used for being connected with other circuits, the capacitor terminal JP is provided with two terminals, and the anode and the cathode of the polarized electrolytic capacitor are respectively connected with the two terminals on the JP, the protection circuit is characterized in that the capacitor reverse connection protection circuit consists of an AND gate U2, a triode Q, a light emitting diode ED, a relay Q, a direct current power circuit and diodes D, D and D, the anode of the polarized electrolytic capacitor E is connected with one terminal of the JP through a normally open point of the relay JDQ, the cathode of the E is connected with the other terminal of the JP, the anode of the E is sequentially connected with the two input ends of the AND gate U2 through a normally open point of the relay JDQ and the resistor R, the cathode of the E is connected with the two input ends of the AND gate U2 through the resistor R, the cathode of the U2 is connected with the power supply ground, the two input ends of the anode of the U2 and the cathode of the power supply U2 are respectively connected with the power supply, the anode of the power supply U2 and the two input ends of the anode of the power supply U2, and the anode of the two input ends of the power;

the output end of the AND gate U2A is connected to the base of a triode Q2 through a resistor R11, a Q2 is an NPN type triode, the emitter of the triode Q2 is connected to the power ground, the collector of the triode Q2 is connected to the positive electrode of the power supply after being connected with the coil of a relay JDQ2 in series, and the output end of the AND gate U2B is connected to the power ground through a resistor R12 and a light emitting diode L ED2 in sequence.

The invention relates to a protection circuit for realizing the reverse connection of a polar electrolytic capacitor by using an AND gate, wherein a direct current power supply circuit consists of a full-bridge rectification circuit formed by a transformer TB2, a three-terminal voltage-stabilizing tube PV2, an electrolytic capacitor E5, an electrolytic capacitor E6 and diodes D15, D16, D17 and D18, a primary side of a transformer TB2 is connected to an alternating current commercial power, a secondary side of the transformer TB2 is connected to the input end of the full-bridge rectification circuit, the anode of the output end of the full-bridge rectification circuit is connected to the input end of the three-terminal voltage-stabilizing tube PV2, and the output end of the; the electrolytic capacitor E6 is arranged at the output end of the full-bridge rectification circuit, and the electrolytic capacitor E5 is arranged at the output end of the three-terminal voltage regulator tube PV 2.

The invention relates to a protection circuit for realizing the reverse connection of a polar electrolytic capacitor by using an AND gate, wherein two ends of a coil of a relay JDQ2 are connected in parallel with a freewheeling diode D14 for preventing the self-induction voltage generated by the relay JDQ2 from being too high, and the anode of the diode D14 is connected to the collector of a triode Q2 and the anode of a cathode power supply.

The protection circuit for realizing the reverse connection of the polar electrolytic capacitor by using the AND gate has the advantages that the resistance values of the resistor R7 and the resistor R8 are both 20k omega, the resistance values of the resistor R9 and the resistor R10 are both 100k omega, and the resistance values of the resistor R11 and the resistor R12 are both 4.7k omega.

The circuit has the advantages that the circuit is composed of a polar electrolytic capacitor E1, a capacitor terminal JP1, a NOT gate U1A, a NOT gate U1B, a NOT gate U1C, a triode Q1, a relay JDQ1, a light emitting diode L ED L and a direct current power supply circuit, when the JP L does not connect the E L into an experimental circuit or the experimental circuit is connected into the experimental circuit but is not electrified, the input ends of the U1L and the U1L are respectively pulled to be low potential by resistors R L and R L, the U1L outputs high level to enable the JDED L not to be lightened, the high level output by the U1L outputs low level after passing through the U1L, the Q L is cut off to enable the electromagnetic coil of the U L not to be electrified, the E L is not connected into the experimental circuit, when the JP L is connected into the experimental circuit incorrectly, the JDU 1L outputs low level, the high level when the JDU 72 is connected into the experimental circuit, the JDED L, the experimental circuit, the U L outputs the low level, the high level when the JDU 72 is connected to enable the experimental circuit, the experimental circuit 72 to enable the high level, the experimental circuit 72 to output the high level, the experimental circuit L to enable the experimental circuit to output of the experimental circuit 72, the experimental circuit to output of the experimental circuit to be connected with the high level, the experimental circuit 72, the experimental circuit 72 to enable the experimental circuit to enable the experimental.

The invention discloses a protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an AND gate, which is composed of a polar electrolytic capacitor E1, a capacitor terminal JP2, an AND gate U2A, an AND gate U2B, a triode Q2, a relay JDQ2, a light emitting diode L ED2 and a direct current power supply circuit, when the JP2 does not connect E4 into an experimental circuit or the experimental circuit is connected into the experimental circuit but is not electrified, the input ends of U2A and U2C are respectively pulled to be low potential by resistors R C and R C, the U2C outputs low level to enable the ED C not to be lighted, the U2C outputs low level, the Q C is cut off to enable a solenoid coil of the JDQ C not to be electrified, the E C is not connected into the experimental circuit, when the JP C is mistakenly connected into the experimental circuit, the input end of the U2C is low level, the input end of the U2C is high level, the U2C is connected to be high level, the JDQ C is connected into the experimental circuit to enable the experimental circuit to be not electrified, the experimental circuit, the high level, the input end of the JDQ C, the experimental circuit is connected into the experimental circuit 72, the experimental circuit is connected into the high level, the experimental circuit 72, the experimental circuit is connected into the experimental circuit, the experimental circuit 72, the experimental circuit is connected with the high level, the high level of the experimental circuit is used for prompting the high level, the high.

Therefore, no matter the protection circuit which is formed by a NOT gate device or an AND gate device and is reversely connected with the polar electrolytic capacitor can keep the positive electrode end of the electrolytic capacitor in a disconnected state all the time when the electrolytic capacitor to be protected is wrongly connected into other experimental circuits, the electrolytic capacitor cannot be put into the circuit, and the prompt is given by lightening a light-emitting diode, so that the occurrence of accidents of capacitor damage, explosion and even harm to life and property caused by reverse connection of the electrolytic capacitor is avoided.

Drawings

FIG. 1 is a circuit diagram of a protection circuit for reverse connection of a polar electrolytic capacitor using a NOT gate according to the present invention;

fig. 2 is a circuit diagram of a protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an and gate according to the invention.

In FIG. 1, a capacitor terminal JP1 is 1, a polar electrolytic capacitor E1 is 2, a NOT gate U1A is 3, a NOT gate U1B is 4, a NOT gate U1C is 5, a triode Q1 is 6, a relay JDQ1 is 7, a transformer TB1 is 8, a three-terminal regulator PV1 is 9, and a light emitting diode L ED1 is 10.

In FIG. 2, 11 capacitor terminals JP2, 12 have polar electrolytic capacitors E4, 13 AND gates U2A, 14 AND gate U2B, 15 LED L ED2, 16 triode Q2, 17 relay JDQ2, 18 transformer TB2, and 19 three-terminal regulator PV 2.

Detailed Description

The invention is further described with reference to the following figures and examples.

Embodiment 1, as shown in fig. 1, shows a circuit diagram of an inventive protection circuit for realizing reverse connection of a polar electrolytic capacitor by using a not gate, which is composed of a capacitor terminal JP1 (1), a polar electrolytic capacitor E1 (2) and a reverse capacitor protection circuit, wherein the capacitor terminal JP1 is composed of two terminals (the numbers of which are respectively 1 and 2), the positive electrode of the polar electrolytic capacitor E1 is connected with the terminal with the number of 1 in JP1 through the normally open point of a relay JDQ1, and the negative electrode of E1 is directly connected with the terminal with the number of 2 in JP 1. E1 is a polar electrolytic capacitor protected for connecting to other experimental circuits, and JP1 is used for connecting E1 to other circuits.

The reverse capacitor protection circuit comprises a NOT gate U1A (3), a NOT gate U1B (4), a NOT gate U1C (5), a triode Q1 (6), a relay JDQ1 (7), a light emitting diode L ED1 (10), a direct current power supply circuit, diodes D1, D2, D3 and D4, wherein the input end of the NOT gate U1A is connected with the terminal 1 of JP1 through a resistor R1, the input end of U1C is connected with the terminal 2 of JP2 through a resistor R2, and the resistors R1 and R2 have large resistance values (such as 20k omega) to play a role in current limiting and isolation, so that the reverse capacitor protection circuit cannot be destructively affected after the E1 is connected into the experimental circuit through JP 1.

The anode and cathode of the diode D1 are respectively connected with the input end of U1C and the anode of a power supply, the anode and cathode of D2 are respectively connected with the anode of U1A and the anode of the power supply, the anode and cathode of D3 are respectively connected with the ground of the power supply and the input end of U1A, and the anode and cathode of D4 are respectively connected with the ground of the power supply and the input end of U1C. D1, D2 play a role of high-level clamping, D3, D4 play a role of low-level clamping, when E1 is reversely connected through JP1 and the voltage applied to the positive pole of D1 is greater than Vcc (at least 0.7V greater than Vcc), D1 is conducted to enable the potential of the input end of U1C not to be higher than Vcc +0.7V, and D3 is conducted to enable the voltage of the input end of U1A not to be lower than-0.7V; when E1 is properly connected, when the voltage applied to the positive pole of D2 is greater than Vcc (at least 0.7V greater than Vcc), D2 is turned on so that the voltage at the input end of U1A does not exceed Vcc +0.7V, and D4 is turned on so that the voltage at the input end of U1C does not fall below-0.7V, so as to ensure the normal operation of gates U1A and U1C.

The input ends of NOT gates U1A and U1C are respectively connected to the power ground through a resistor R3 and a resistor R4, and when JP1 is not connected to other experimental circuits or the experimental circuits are connected to other experimental circuits but are not electrified, R3 and R4 respectively pull the potentials of the input ends of the NOT gates U1A and U1C to be low level.

The output end of the NOT gate U1A is connected with the input end of a NAND gate U1B, the output end of the U1B is connected with the base electrode of a triode Q1 through a resistor R6, Q1 is an NPN type triode, the emitter electrode of the triode Q1 is connected to the ground of a power supply, the collector electrode of Q1 is connected with the coil of a relay JDQ1 in series and then connected to the positive electrode of the power supply so as to control the energization and the deenergization of the coil of a relay JDQ1 by utilizing the conduction and the cutoff of Q1, in order to avoid the self-induced high voltage generated at the moment of deenergization of the relay JDQ1, a diode D5 is connected to the two ends of the relay Q1 in parallel to play a role of follow current, the output end of the NOT gate U1C is connected to the positive electrode of the power supply through a resistor R5 and a light emitting diode L ED 1.

The direct current power supply circuit consists of a full-bridge rectification circuit formed by a transformer TB1 (8), a three-terminal voltage-regulator tube PV1 (9), an electrolytic capacitor E2, an electrolytic capacitor E3 and diodes D6, D7, D8 and D9, wherein the primary side of the transformer TB1 is connected to an alternating current mains supply, the secondary side of the transformer TB1 is connected to the input end of the full-bridge rectification circuit, the anode of the output end of the full-bridge rectification circuit is connected to the input end of a three-terminal voltage-regulator tube PV1, and the output end of a three-terminal voltage-regulator; the electrolytic capacitor E3 is arranged at the output end of the full-bridge rectification circuit, the electrolytic capacitor E2 is arranged at the output end of the three-terminal voltage regulator tube PV1, and the E3 and the E2 achieve the functions of filtering and voltage regulation.

When the transformer TB is connected with a power supply, the reverse capacitor connection protection circuit starts to work.

When JP1 is not connected to other experimental circuits or is connected to other experimental circuits but the experimental circuits are not electrified, the resistors R3 and R4 respectively pull the input ends of the NOT gate U1A and U1C to the ground potential, the output end side of the U1A is high potential due to the low potential of the input end of the U1A, the U1B outputs low potential through the inversion of U1B, the triode Q1 is cut off, the electromagnetic coil of the relay Q1 is not electrified, the JD1 normally-open contact is not operated, the protected capacitor E1 is not connected into the experimental circuit, and meanwhile, the output end side of the U1C is low potential, the output end side of the indicator is high potential, the two ends of the indicator lamp are not electrified, so the light-emitting diode L ED1 cannot emit light at this time, the polarized electrolytic capacitor E1 cannot be put into an external circuit, and the error indicator lamp:

when JP1 is connected to the experimental circuit in an error mode and the experimental circuit is powered on, current formed by an external experimental circuit forms a loop through R2, R4, D3 and R1, lower positive and upper negative voltages are formed at two ends of R4, if the voltage is much higher than Vcc, the voltage of Vcc +0.7V can be clamped by D1, the potential of the output end of U1C is made to be 0, an indicator lamp L ED1 for marking E1 wiring error is lightened, the input end of U1A bears-0.7V, the output end of U1A is high, and after the U1B is inverted, U1B outputs low level, Q1 is cut off, a relay JDQ is not operated, so that a capacitor E1 cannot be put into use, and E1 is protected.

When JP1 is connected to the experimental circuit in a correct way and the experimental circuit is powered on, the current formed by the external experimental circuit forms a loop through R1, R3, D4 and R2, the upper positive and lower negative voltages are formed at the two ends of R3, if the voltage is much higher than Vcc, the voltage of Vcc +0.7V can be clamped by D2, the potential of the output end of U1A is made to be 0, Q1 is conducted after the phase inversion of U1B, the relay JDQ is operated, and therefore the capacitor E1 is put into the circuit, at the moment, the input end of U1B bears the voltage of-0.7V, the output end of U1B is made to be high, the two ends of the error mark indicator lamp L ED are equipotential, and therefore no light is emitted.

Embodiment 2, as shown in fig. 2, there is shown a circuit diagram of a protection circuit of the present invention for realizing reverse connection of a polar electrolytic capacitor by an and gate, which is composed of a capacitor terminal JP2 (11), a polar electrolytic capacitor E4 (12) and a reverse connection protection circuit of the capacitor, E1 is a polar electrolytic capacitor protected for connection to other experimental circuits, the capacitor terminal JP2 is used for connecting E1 to other circuits, JP jd 2 has two terminals labeled 1 and 2 respectively, the positive electrode of E4 is connected to terminal 1 of JP2 through the normally open point of a relay JDQ2, and the negative electrode of E4 is directly connected to terminal 2 of JP2, the reverse connection protection circuit is composed of an and gate U2A (13), an and gate U2B (14), a light emitting diode L2 (15), a triode Q2 (16), a relay Q jd 5 (17), a dc power supply circuit, and diodes D10, D11, D12 and 68642 are also shorted together with the two input terminals ED 599 of the input terminal ED 599 and the input terminal U599.

Two input ends of the AND gate U2A are connected with a terminal 1 of JP2 through a resistor R7, two input ends of the U2B are connected with a terminal 2 of JP2 through a resistor R8, and resistors with larger resistance values (such as 20k omega) are adopted for R7 and R8 to play a role in current limiting and isolating, so that the E2 is ensured not to have destructive influence on a reverse connection protection circuit of a capacitor after being connected to an experimental circuit through JP 2. The direct current power supply circuit is used for providing stable direct current, and the positive pole of the direct current is Vcc. The input end of the AND gate U2A and the input end of the AND gate U2B are respectively connected to the power ground through a resistor R9 and a resistor R10, and when JP2 is not connected to other experimental circuits or the experimental circuits are connected to other experimental circuits but are not electrified, R9 and R10 respectively pull the potentials at the input ends of the AND gate U2A and the AND gate U2B to be low level.

Similarly, the anode and cathode of the diode D10 are connected to the input terminal of U2B and the power supply anode, the anode and cathode of D11 are connected to the anode and power supply anode of U2A, the anode and cathode of D12 are connected to the power ground and the input terminal of U2A, and the anode and cathode of D13 are connected to the power ground and the input terminal of U2B. D10, D11 play a role of high-level clamping, D12, D13 play a role of low-level clamping, when E2 is reversely connected through JP2 and the voltage applied to the positive pole of D10 is greater than Vcc (at least 0.7V greater than Vcc), D10 is conducted to enable the potential of the input end of U2B not to be higher than Vcc +0.7V, and D12 is conducted to enable the voltage of the input end of U2A not to be lower than-0.7V; when E1 is properly connected, when the voltage applied to the positive pole of D11 is greater than Vcc (at least 0.7V greater than Vcc), D11 is turned on so that the voltage at the input end of U2A does not exceed Vcc +0.7V, and D13 is turned on so that the voltage at the input end of U2B does not fall below-0.7V, so as to ensure the normal operation of AND gates U2A and U2B.

The output end of an AND gate U2A is connected with the base electrode of a triode Q2 through a resistor R11, a Q2 is an NPN type triode, the emitter electrode of a triode Q2 is connected with a power ground, the collector electrode of the triode Q2 is connected with the positive power of a relay JDQ2 in series and then is connected with the positive power of the relay, so that the power-on and power-off of the coil of the relay JDQ2 are controlled through the conduction and the cut-off of the triode Q2.

The direct current power supply in the embodiment is composed of a full-bridge rectifying circuit formed by a transformer TB2 (18), a three-terminal voltage regulator tube PV2 (19), an electrolytic capacitor E5, an electrolytic capacitor E6 and diodes D15, D16, D17 and D18, and a direct current power supply circuit in the embodiment is the same as that in the embodiment 1 except that the components are different in number.

When the transformer TB2 is powered on, the capacitor protection circuit in this embodiment starts to operate.

When JP2 is not connected to other experimental circuits or is connected to other experimental circuits but the experimental circuits are not electrified, the resistors R9 and R10 respectively pull the input ends of the AND gate U2A and the AND gate U2B to the ground potential (low level), the U2A outputs low potential, the Q2 is cut off, the electromagnetic coil of the JDQ2 is not electrified, the normally open contact of the JDQ2 is not operated, the protected capacitor E4 is not connected to the experimental circuits, and meanwhile, because the input end of the U1B is low potential and the output end thereof is low potential, the two ends of the indicator light L ED2 are equipotential and therefore do not emit light, the capacitor E4 is not put into an external circuit at this time, and the error indicator light L ED2 does not emit light either:

when JP2 is connected to the experimental circuit in an error mode and the experimental circuit is powered on, current formed by an external experimental circuit forms a loop through R8, R10, D12 and R7, lower positive and upper negative voltages are formed at R10, if the voltage is much higher than Vcc, the output end of U2B is clamped to Vcc +0.7V by D10, so that the output end of U2B is high in potential, an indicator lamp L ED2 for marking E4 wiring error is lightened, at the moment, the input end of U2A bears-0.7V voltage, the output end of U2A is low, Q2 is cut off, a relay JDQ2 does not act, therefore, a capacitor E4 cannot be put into use, and E4 is protected.

When JP1 is connected to the experimental circuit in a correct way and the experimental circuit is powered on, the current formed by the external experimental circuit forms a loop through R1, R9, D13 and R8, and the upper positive and lower negative voltages are formed at the two ends of R9, if the voltage is much higher than Vcc, the input end of U1A is clamped to Vcc +0.7V by D11, so that the output end of U2A is high-potential, Q2 is conducted, the relay Q2 is operated, and therefore the capacitor E4 is put into the circuit, at the moment, the input end of U2B bears-0.7V, the output end of U2B is low-potential, and the two ends of the error mark indicator lamp L ED2 are equipotential, so that no light is emitted.

Claims

1. A protection circuit for realizing reverse connection of a polarized electrolytic capacitor by using a NOT gate comprises a capacitor terminal JP1 (1), a polarized electrolytic capacitor E1 (2) and a reverse connection protection circuit of the capacitor, wherein E1 is a polarized electrolytic capacitor protected and connected into other circuits, the capacitor terminal JP1 comprises two terminals, and the anode and the cathode of E1 are connected with the capacitor terminal JP1, the protection circuit is characterized in that the reverse connection protection circuit of the capacitor comprises a NOT gate U1A (3), a NOT gate U1B (4), a NOT gate U1C (5), a triode Q1 (6), a relay JDQ1 (7), a light emitting diode L ED1 (10), a direct current power circuit, diodes D1, D2, D3 and D4, the anode of the polarized electrolytic capacitor E1 is connected with one terminal of the capacitor terminal through a normally open point of the relay Q1, the cathode of the E1 is connected with the other anode of the JP1, the E72 is connected with the power source U72, the anode of the power source and the negative pole of the power source of the NOT gate U1, the power source is connected with the power source, the positive input terminal of the NOT gate U72, the negative pole of the power source of the NOT gate U1, the positive input terminal of the power source is connected with the power source, the positive input terminal of the power source, the negative gate of the power source of the NOT gate U72, the power source of the NOT gate U72, the NOT gate U72 is connected with the power source U72, the positive gate U72, the power source of the negative gate of the power source;

2. The protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an inverter according to claim 1, wherein: the direct current power supply circuit consists of a full-bridge rectification circuit formed by a transformer TB1 (8), a three-terminal voltage-regulator tube PV1 (9), an electrolytic capacitor E2, an electrolytic capacitor E3 and diodes D6, D7, D8 and D9, wherein the primary side of the transformer TB1 is connected to an alternating current mains supply, the secondary side of the transformer TB1 is connected to the input end of the full-bridge rectification circuit, the anode of the output end of the full-bridge rectification circuit is connected to the input end of a three-terminal voltage-regulator tube PV1, and the output end of a three-terminal voltage-regulator; the electrolytic capacitor E3 is arranged at the output end of the full-bridge rectification circuit, and the electrolytic capacitor E2 is arranged at the output end of the three-terminal voltage regulator tube PV 1.

3. The protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an inverter according to claim 1 or 2, wherein: two ends of the coil of the relay JDQ1 (7) are connected in parallel with a freewheeling diode D5 for preventing the self-inductance voltage generated by the diode D5 from being too high, and the anode of the diode D5 is connected to the collector of the triode Q1 (6) and the anode of the negative electrode power supply.

4. The protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an inverter according to claim 1 or 2, wherein: the resistance values of the resistor R1 and the resistor R2 are both 20k omega, the resistance values of the resistor R3 and the resistor R4 are both 100k omega, and the resistance values of the resistor R5 and the resistor R6 are both 4.7k omega.

5. A protection circuit for realizing the reverse connection of a polarized electrolytic capacitor by an AND gate comprises a capacitor terminal JP (11), a polarized electrolytic capacitor E (12) and a capacitor reverse connection protection circuit, wherein the E is the polarized electrolytic capacitor to be protected and used for being connected with other circuits, the capacitor terminal JP is provided with two terminals, and the anode and the cathode of the polarized electrolytic capacitor are respectively connected with the two terminals on the JP, the protection circuit is characterized in that the capacitor reverse connection protection circuit consists of an AND gate U2 (13), an AND gate U2 (14), a triode Q (16), a light emitting diode ED (15), a relay JDQ (17), a direct current power circuit and diodes D, D and D, the anode of the polarized electrolytic capacitor E is connected with one terminal of the JP through a normally open point of the relay JDQ, the cathode of the E is connected with the other terminal of the JP, the anode of the E is sequentially connected with the two input ends of the AND gate U2 through a normally open point of the relay JDQ, the resistor R and the two input ends of the anode of the power source U2 and the cathode of the power source U2, the resistor R and the anode of the power source U2 are respectively connected with the ground, the two input ends of the power source U2 and the anode of the power source D, the cathode of the diode D and the diode D are respectively connected with the anode of the power source U2, and the anode of the power source U2;

6. The protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an AND gate as claimed in claim 5, wherein: the direct current power supply circuit consists of a full-bridge rectification circuit formed by a transformer TB2 (18), a three-terminal voltage-regulator tube PV2 (19), an electrolytic capacitor E5, an electrolytic capacitor E6 and diodes D15, D16, D17 and D18, wherein the primary side of the transformer TB2 is connected to an alternating current mains supply, the secondary side of the transformer TB2 is connected to the input end of the full-bridge rectification circuit, the anode of the output end of the full-bridge rectification circuit is connected to the input end of a three-terminal voltage-regulator tube PV2, and the output end of a three-terminal voltage-regulator; the electrolytic capacitor E6 is arranged at the output end of the full-bridge rectification circuit, and the electrolytic capacitor E5 is arranged at the output end of the three-terminal voltage regulator tube PV 2.

7. A protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an AND gate according to claim 5 or 6, characterized in that: two ends of the coil of the relay JDQ2 (17) are connected in parallel with a freewheeling diode D14 for preventing the self-inductance voltage generated by the coil from being too high, and the anode of the diode D14 is connected to the collector of the triode Q2 (16) and the anode of the negative electrode power supply.

8. A protection circuit for realizing reverse connection of a polar electrolytic capacitor by using an AND gate according to claim 5 or 6, characterized in that: the resistance values of the resistor R7 and the resistor R8 are both 20k omega, the resistance values of the resistor R9 and the resistor R10 are both 100k omega, and the resistance values of the resistor R11 and the resistor R12 are both 4.7k omega.