Search

CN-122026710-A - Soft-start built-in bypass relay control circuit and control method thereof

CN122026710ACN 122026710 ACN122026710 ACN 122026710ACN-122026710-A

Abstract

The invention belongs to the technical field of relay control circuits, and relates to a soft-start built-in bypass relay control circuit and a control method thereof, the circuit comprises a main control circuit, a bypass signal isolation conversion circuit, a relay action circuit I, a relay action circuit II, a voltage conversion circuit, an energy storage circuit, a rectification circuit, a voltage feedback circuit and a connection relation thereof. According to the invention, the relay action circuit I and the relay action circuit II are arranged, namely, 2 paths of relays with conversion functions are added, and +24V, 0V or-24V can be output at an output interface by controlling the actions of the 2 relays, so that the actions of the magnetic holding contactor are controlled, and the load of the switching power supply is reduced by using the magnetic holding contactor to keep low power consumption after the actions, and the service life of the switching power supply can be effectively prolonged.

Inventors

  • YU QINGYU

Assignees

  • 上海数恩电气科技有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (9)

  1. 1. A control method of a soft start built-in bypass relay is characterized by comprising the following steps: After the singlechip U9 receives an external bypass signal through the bypass signal isolation conversion circuit, the singlechip U9 controls the relay K1 to act, at the moment, the relay K1 outputs 0V, the relay K2 outputs 24V, and the magnetic latching contactor is closed; When soft stop is needed, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the relay K2 outputs 0V, and the magnetic latching contactor is disconnected; when the magnetic latching contactor is in operation, an external 380V power supply is suddenly powered off, after the voltage of a bus is detected to be reduced to a threshold value, the main board singlechip sends a bypass cutting signal to the singlechip U9 through a bypass signal isolation conversion circuit, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the magnetic latching contactor is disconnected, after the magnetic latching contactor is in operation disconnection, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the relay K2 outputs 24V, and the magnetic latching contactor can keep in a disconnection state continuously.
  2. 2. A soft-start built-in bypass relay control circuit is used for realizing the control method of claim 1 and is characterized by comprising a main control circuit, wherein one input end of the main control circuit receives an external bypass signal through a bypass signal isolation conversion circuit, two output ends of the main control circuit are connected with a relay action circuit I and a relay action circuit II, the relay action circuit I and the relay action circuit II are symmetrically arranged and connected to a multipath magnetic latching contactor, the main control circuit is electrically connected with the output end of a voltage conversion circuit or an energy storage circuit, the output end of the voltage conversion circuit is electrically connected with the input end of the energy storage circuit, and the input end of the voltage conversion circuit is electrically connected with the output end of a rectifying circuit.
  3. 3. The soft-start built-in bypass relay control circuit according to claim 2, wherein the bypass signal isolation conversion circuit comprises a photo coupler U7, a collector of a photo transistor of the photo coupler U7 is connected with an input end RLY-CON of the main control circuit, and two ends of a light emitting diode of the photo coupler U7 are electrically connected with a bypass signal connection terminal through a resistor and a capacitor.
  4. 4. The soft-start built-in bypass relay control circuit according to claim 2, wherein the relay action circuit I comprises a relay K1 and a triode Q2, wherein the base electrode of the triode Q2 is connected with an output end RLY-OFF of the main control circuit through a resistor and a capacitor, the emitter electrode of the triode Q2 is grounded, the collector electrode of the triode Q2 is connected with a coil pin of the relay K1, the contact point I of the relay K1 is grounded, the contact point II is connected with 24V, and the common end is connected to the multi-path magnetic latching contactor.
  5. 5. The soft-start built-in bypass relay control circuit according to claim 4, wherein the relay action circuit II comprises a relay K2 and a triode Q3, wherein the base electrode of the triode Q3 is connected with an output end RLY-ON of the main control circuit through a resistor and a capacitor, the emitter electrode of the triode Q3 is grounded, the collector electrode of the triode Q3 is connected with a coil pin of the relay K2, the contact one of the relay K2 is grounded, the contact two is connected with 24V, and the common end is connected to the multi-path magnetic latching contactor.
  6. 6. The soft start built-in bypass relay control circuit of claim 2, wherein the voltage conversion circuit comprises a 540V to 24V circuit, a 24V to 5V circuit, wherein an input of the 540V to 24V circuit is connected to an output of the rectifying circuit, and an output of the 540V to 24V circuit is connected to an input of the 24V to 5V circuit.
  7. 7. The soft-start built-in bypass relay control circuit according to claim 6, wherein the 540V-to-24V circuit comprises a switching power supply PWM driving chip U3, a switching tube Q1 and a transformer T2, wherein a power supply input end of the switching power supply PWM driving chip U3 is connected to an output end of the rectifying circuit through a starting resistor, an output end PWM of the switching power supply PWM driving chip U3 is connected to a gate of the switching tube Q1 through a diode and a resistor, a drain electrode of the switching tube Q1 is connected to an input end of the transformer T2, an input end of the transformer T2 is connected to an output end of the rectifying circuit, and a source electrode of the switching tube Q1 is connected to an input end of the switching power supply PWM driving chip U3 through a resistor and a capacitor.
  8. 8. The soft-start built-in bypass relay control circuit according to claim 7, wherein COMP pin of the switching power supply PWM driving chip U3 is connected to a collector of a phototransistor of the photocoupler U2.
  9. 9. The soft-start built-in bypass relay control circuit according to claim 2, wherein the 24V output end of the voltage conversion circuit is electrically connected with a voltage feedback circuit, and the voltage feedback circuit is electrically connected with a switching power supply PWM driving chip U3 through a photo coupler U2.

Description

Soft-start built-in bypass relay control circuit and control method thereof Technical Field The invention relates to the technical field of relay control, in particular to a soft-start built-in bypass relay control circuit and a control method thereof. Background The soft starter is motor control equipment integrating soft start, soft stop, light load energy saving and multifunctional protection, realizes a smooth starting motor without impact in the whole starting process, and can adjust various parameters in the starting process, such as a current limiting value, starting time and the like according to the characteristics of motor load. After the controllable silicon of the soft starter is completely conducted, the singlechip sends out a bypass signal, and the bypass control board controls the magnetic latching contactor to conduct after receiving the signal and stably switches to bypass operation. When the external power supply is powered off, the singlechip sends a bypass disconnection signal by judging the decline of the bus voltage, and the bypass control board controls the action of the magnetic latching contactor to be disconnected after receiving the disconnection signal. The current magnetic latching contactor has larger power consumption in the operation process, and has great burden on the whole switching power supply. Disclosure of Invention The invention aims to solve the technical problems in the background art, and provides a control circuit and a control method for a soft-start built-in bypass relay. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a control method of a soft-start built-in bypass relay comprises the following steps: After the singlechip U9 receives an external bypass signal through the bypass signal isolation conversion circuit, the singlechip U9 controls the relay K1 to act, at the moment, the relay K1 outputs 0V, the relay K2 outputs 24V, and the magnetic latching contactor is closed; When soft stop is needed, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the relay K2 outputs 0V, and the magnetic latching contactor is disconnected; when the magnetic latching contactor is in operation, an external 380V power supply is suddenly powered off, after the voltage of a bus is detected to be reduced to a threshold value, the main board singlechip sends a bypass cutting signal to the singlechip U9 through a bypass signal isolation conversion circuit, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the magnetic latching contactor is disconnected, after the magnetic latching contactor is in operation disconnection, the singlechip U9 controls the relay K2 to act, at the moment, the relay K1 outputs 24V, the relay K2 outputs 24V, and the magnetic latching contactor can keep in a disconnection state continuously. A soft-start built-in bypass relay control circuit is used for realizing the control method and comprises a main control circuit, one input end of the main control circuit receives an external bypass signal through a bypass signal isolation conversion circuit, two output ends of the main control circuit are connected with a relay action circuit I and a relay action circuit II, the relay action circuit I and the relay action circuit II are symmetrically arranged and connected to a multipath magnetic latching contactor, the main control circuit is electrically connected with the output end of a voltage conversion circuit or an energy storage circuit, the output end of the voltage conversion circuit is electrically connected with the input end of the energy storage circuit, and the input end of the voltage conversion circuit is electrically connected with the output end of a rectifying circuit. The control circuit of the invention is further defined by the following technical scheme, the bypass signal isolation conversion circuit comprises a photoelectric coupler U7, the collector of a photoelectric transistor of the photoelectric coupler U7 is connected with the input end RLY-CON of the main control circuit, and two ends of a light emitting diode of the photoelectric coupler U7 are electrically connected with a bypass signal wiring terminal through a resistor and a capacitor. The following is a technical scheme further defined by the control circuit in the invention, the relay action circuit I comprises a relay K1 and a triode Q2, wherein the base electrode of the triode Q2 is connected with the output end RLY-OFF of the main control circuit through a resistor and a capacitor, the emitter electrode of the triode Q2 is grounded, the collector electrode of the triode Q2 is connected with a coil pin of the relay K1, the contact I of the relay K1 is grounded, the contact II is connected with 24V, and the public end is connected to the multipath magnetic latching contactor. The following is a technical scheme further defined by the control circuit in t