Circuit for preventing electric shock arc discharge of output relay

Abstract

The utility model relates to the technical field of circuits, in particular to a circuit for preventing an output relay from electric shock arc discharge, which is characterized in that a relay contact voltage detection circuit is connected with a power supply circuit of a battery changing cabinet, the output end of the power supply circuit of the battery changing cabinet is connected with a relay, the relay is connected with a resistor R8, the resistor R8 is connected with an MOS tube Q1, the MOS tube Q1 is connected with a resistor R7, and the resistor R7 is connected with a relay contact voltage detection circuit. The relay contact voltage detection circuit comprises a differential amplification circuit and a logic circuit, the differential amplification circuit is connected with the relay, the logic circuit is connected with the differential amplification circuit, and the logic circuit is connected with the resistor R7. Compared with the prior art, the circuit for preventing electric shock arc discharge of the output relay adds relay contact voltage detection, can effectively prevent the relay from being closed when the voltage difference is large, does not affect the closing of the relay when the voltage difference is small, and does not affect the turn-off of the relay. The safety of the relay is effectively protected, the service life of the relay is prolonged, and the reliability of the power supply is improved.

Description

Technical Field

[0001] The utility model relates to the field of circuit technology, and particularly relates to an arc suppression circuit for the output relay contact.

Background Art

[0002] In the power supply of the existing battery replacement cabinet, there is only an output relay part. When the battery is connected to the power output, when the relay is attracted when the voltage difference across the relay contacts is large, a large current arc may be generated, which may cause the relay contacts to be attracted and stuck. When the power is cut off after the contacts are attracted and stuck, they cannot bounce back, resulting in damage to the relay. Long-term arcing will also reduce the service life of the relay.

Content of the Utility Model

[0003] In order to overcome the above problems, the utility model proposes an arc suppression circuit for the output relay contact that can effectively solve the above problems.

[0004] A technical solution provided by the utility model to solve the above technical problems is: to provide an arc suppression circuit for the output relay contact, which includes a battery replacement cabinet power supply circuit and a relay contact voltage detection circuit, and the relay contact voltage detection circuit is connected to the battery replacement cabinet power supply circuit; a relay is connected to the output end of the battery replacement cabinet power supply circuit, a resistor R8 is connected to the relay, a MOS transistor Q1 is connected to the resistor R8, and a resistor R7 is connected to the MOS transistor Q1; the relay contact voltage detection circuit includes a differential amplifier circuit and a logic circuit, the differential amplifier circuit is connected to the relay, the logic circuit is connected to the differential amplifier circuit, and the logic circuit is connected to the resistor R7.

[0005] Preferably, the logic circuit includes a U3 AND gate, and the signal output interface Vcontrol of the U3 AND gate is connected to the resistor R7.

[0006] Preferably, the battery replacement cabinet power supply circuit includes a current limiting resistor R8, a MOS transistor Q1, a resistor R7, and a resistor R6. The current limiting resistor R8 is connected to the relay, and the current limiting resistor R8, the resistor R7, and the resistor R6 are respectively connected to the MOS transistor Q1.

[0007] Preferably, the differential amplifier circuit includes a sampling resistor R0, resistors R1, R2, R3, R4, and a U1 operational amplifier OP. The sampling resistor R0 is respectively connected to the relay, the resistor R1, and the resistor R2. After the resistor R1 is connected to the resistor R3, they are jointly connected to the U1 operational amplifier OP. After the resistor R2 is connected to the resistor R4, they are jointly connected to the U1 operational amplifier OP.

[0008] Preferably, the logic circuit includes a U2 comparator COMP and a U3 AND gate. The negative port of the U2 comparator COMP is connected to the signal output terminal of the U1 operational amplifier OP, the positive port of the U2 comparator COMP is connected to Vref, the output port of the U2 comparator COMP is connected to the U3 AND gate for logical determination, the VMCU signal is connected to the U3 AND gate, and the output port Vcontrol of the U3 AND gate is connected to the resistor R7.

[0009] Preferably, the relay is a normally open relay.

[0010] Preferably, the resistor R7 is a driving resistor.

[0011] Compared with the prior art, the anti-output relay contact arcing circuit of the present invention adds the detection of the relay contact voltage. When the pressure difference is large, it can effectively prevent the relay from being attracted. When the pressure difference is small, it does not affect the attraction of the relay and does not affect the turn-off of the relay, effectively protecting the safety of the relay and extending the service life of the relay. The cost of circuit components is low, and the reliability of the power supply is further improved.

Description of the Drawings

[0012] Figure 1 It is a schematic diagram of the anti-output relay contact arcing circuit of the present invention.

Detailed Embodiments

[0013] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0014] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only relative positions on the specified view, rather than absolute positions.

[0015] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0016] Please refer to Figure 1, the arc-suppression circuit for the output relay contacts of the present utility model includes a power supply circuit Part1 of the battery replacement cabinet and a relay contact voltage detection circuit, and the relay contact voltage detection circuit is connected to the power supply circuit of the battery replacement cabinet.

[0017] The power supply circuit of the battery replacement cabinet is connected with a relay RELAY at the output end, the relay RELAY is connected with a resistor R8, the resistor R8 is connected with a MOS transistor Q1, and the MOS transistor Q1 is connected with a resistor R7. The relay RELAY is a normally open relay.

[0018] The relay contact voltage detection circuit includes a differential amplifier circuit part2 and a logic circuit Part3. The differential amplifier circuit part2 is connected with the relay RELAY, the logic circuit Part3 is connected with the differential amplifier circuit part2, and the logic circuit Part3 is connected with the resistor R7. The resistor R7 is a driving resistor.

[0019] The logic circuit Part3 includes a U3 AND gate, and the signal output interface Vcontrol of the U3 AND gate is connected with the resistor R7.

[0020] The power supply circuit Part1 of the battery replacement cabinet includes a battery, a relay RELAY, a current-limiting resistor R8, a MOS transistor Q1, a resistor R7, and a resistor R6. The current-limiting resistor R8 is connected with the relay RELAY, and the current-limiting resistor R8, the resistor R7, and the resistor R6 are respectively connected with the MOS transistor Q1.

[0021] In the power supply circuit Part1 of the battery replacement cabinet, the positive pole VOUT+ of the power output terminal is connected to the positive pole VBAT+ of the battery, the negative pole VOUT- of the power output terminal is connected to the left pin 1 of the relay RELAY, the negative pole VBAT- of the battery is connected to the right pin 4 of the relay RELAY, the power supply terminal VCC of the relay RELAY is connected to the left pin 3 of the relay RELAY, the pin 2 of the relay RELAY is connected to the upper end of the current-limiting resistor R8, the D pole of the MOS transistor Q1 is connected to the lower end of the current-limiting resistor R8, the G pole of the MOS transistor Q1 is connected to the left end of the resistor R7 and the upper end of the resistor R6, and the S pole of the MOS transistor Q1 is connected to the lower end of the resistor R6 and is grounded together. The resistor R7 is connected to the signal output interface Vcontrol of the U3 AND gate.

[0022] The differential amplifier circuit part2 includes a sampling resistor R0, resistors R1, R2, R3, R4, and a U1 operational amplifier OP. The sampling resistor R0 is respectively connected with the relay RELAY, the resistor R1, and the resistor R2, the resistor R1 and the resistor R3 are connected together and then connected to the U1 operational amplifier OP, and the resistor R2 and the resistor R4 are connected together and then connected to the U1 operational amplifier OP.

[0023] The left end of the sampling resistor R0 is respectively connected to the left end of the resistor R2 and the left end 1 of the relay RELAY. The right end of the sampling resistor R0 is respectively connected to the left end of the resistor R1 and the right end 4 of the relay RELAY. The right end of the resistor R1 is connected to the left end of the resistor R3 and they are connected together to the negative pole of the U1 operational amplifier OP. The right end of the resistor R3 is connected to the signal output port of the U1 operational amplifier OP and is connected to the negative pole of the U2 comparator COMP. The right end of the resistor R2 is connected to the upper end of the resistor R4 and they are connected together to the positive pole of the U1 operational amplifier OP. The U1 operational amplifier OP is powered by VCC, the power supply terminal is connected to VCC, the ground terminal is connected to GND, and the resistor R4 is connected to the ground terminal of the U1 operational amplifier OP.

[0024] The logic circuit Part3 includes the U2 comparator COMP and the U3 AND gate.

[0025] The negative port of the U2 comparator COMP is connected to the signal output end of the U1 operational amplifier OP. The positive port of the U2 comparator COMP is connected to Vref. The output port of the U2 comparator COMP is connected to the U3 AND gate for logical judgment. The VMCU signal is connected to the U3 AND gate. The output port Vcontrol of the U3 AND gate is connected to the resistor R7. The U2 comparator COMP and the U3 AND gate are powered by VCC and the power supply terminals are connected together to VCC. The ground terminals of the U2 comparator COMP and the U3 AND gate are commonly connected to GND.

[0026] Principle description:

[0027] The arc suppression circuit for the output relay contact of the present utility model adds the functions of relay differential pressure detection and logical judgment to the power output relay circuit of the battery replacement cabinet, which can effectively control the differential pressure of the relay contact, thereby preventing the relay contact from arcing due to large differential pressure during suction and causing the relay to be sucked dead, and avoiding the relay from failing to effectively disconnect when receiving the turn-off instruction, thus damaging the relay.

[0028] Working principle: 1. When the voltage difference across the relay contacts is large, the voltage across the sampling resistor R0 is high. The voltage after passing through the operational amplifier OP of U1 is greater than the reference voltage Vref, and the comparator COMP of U2 outputs a low-level signal. At this time, regardless of whether the VMUC outputs a high level or a low level, the AND gate of U3 outputs a low level. At this time, the low level cannot turn on the MOS transistor Q1, and the relay does not pull in. This effectively prevents arcing caused by too large a voltage difference when the power output voltage is connected to the battery. 2. When the voltage difference across the relay contacts is small, the voltage collected by the sampling resistor R0 is low, that is, when the voltage after passing through the operational amplifier OP of U1 is less than Vref, the comparator COMP of U2 outputs a high-level signal. At this time, if the VMUC sends a high-level signal, the AND gate of U3 sends a high level. This signal turns on the MOS transistor Q1 through the drive resistor R7. At this time, the relay operates and pulls in. That is, when the voltage difference is small, it does not affect the normal operating state of the relay. 3. When the MCU sends a turn-off command, at this time the VMUC sends a low level. Since the AND gate of U3 outputs a high level only when both inputs are high levels, otherwise it must output a low level. At this time, regardless of the voltage difference across the relay, that is, regardless of whether the output signal of the comparator COMP of U2 is high level or low level, the AND gate of U3 outputs a low level. At this time, the low level cannot turn on the MOS transistor Q1, and the relay is turned off, without affecting the normal turn-off operating state of the relay.

[0029] Compared with the prior art, the arc-proof output relay contact arcing circuit of the present utility model adds the detection of the relay contact voltage. When the voltage difference is large, it can effectively prevent the relay from pulling in. When the voltage difference is small, it does not affect the pulling in of the relay, and does not affect the turn-off of the relay, effectively protecting the safety of the relay and extending the service life of the relay. The cost of circuit components is low, and the reliability of the power supply is further improved.

[0030] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any modifications, equivalent replacements, and improvements made within the concept of the present utility model shall be included in the patent protection scope of the present utility model.

Claims

1. An arc-suppression circuit for the output relay contacts, characterized in that It includes a power supply circuit of the battery swapping cabinet and a relay contact voltage detection circuit, and the relay contact voltage detection circuit is connected to the power supply circuit of the battery swapping cabinet; The power supply circuit of the battery swapping cabinet is connected with a relay at the output end, the relay is connected with a resistor R8, the resistor R8 is connected with a MOS transistor Q1, and the MOS transistor Q1 is connected with a resistor R7; The relay contact voltage detection circuit includes a differential amplification circuit and a logic circuit, the differential amplification circuit is connected with the relay, the logic circuit is connected with the differential amplification circuit, and the logic circuit is connected with the resistor R7.

2. The arc suppression circuit for the output relay contact as claimed in claim 1, wherein The logic circuit includes a U3 AND gate, and the signal output interface Vcontrol of the U3 AND gate is connected with the resistor R7.

3. The arc-suppression circuit for the output relay contact according to claim 1, wherein The power supply circuit of the battery swapping cabinet includes a current-limiting resistor R8, a MOS transistor Q1, a resistor R7, and a resistor R6. The current-limiting resistor R8 is connected with the relay, and the current-limiting resistor R8, the resistor R7, and the resistor R6 are respectively connected with the MOS transistor Q1.

4. The anti-arc circuit for the output relay contact as claimed in claim 1, wherein The differential amplification circuit includes a sampling resistor R0, resistors R1, R2, R3, R4, and a U1 operational amplifier OP. The sampling resistor R0 is respectively connected with the relay, the resistor R1, and the resistor R2. After the resistor R1 is connected with the resistor R3, they are jointly connected to the U1 operational amplifier OP. After the resistor R2 is connected with the resistor R4, they are jointly connected to the U1 operational amplifier OP.

5. The arc suppression circuit for the output relay contact according to claim 1, characterized in that, The logic circuit includes a U2 comparator COMP and a U3 AND gate. The negative port of the U2 comparator COMP is connected to the signal output end of the U1 operational amplifier OP. The positive port of the U2 comparator COMP is connected to Vref. The output port of the U2 comparator COMP is connected to the U3 AND gate for logical determination. The VMCU signal is connected to the U3 AND gate, and the output port Vcontrol of the U3 AND gate is connected with the resistor R7.

6. The arc-suppression circuit for the output relay contact according to claim 1, wherein The relay is a normally open relay.

7. The arc suppression circuit for the output relay contact as claimed in claim 1, wherein The resistor R7 is a driving resistor.

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