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CN-224233674-U - Safety switch circuit

CN224233674UCN 224233674 UCN224233674 UCN 224233674UCN-224233674-U

Abstract

The utility model discloses a safety switch circuit which comprises a switch, a first port, a second port, a first driving circuit, a second driving circuit, a first holding circuit, a second holding circuit and a time control regulating circuit, wherein the first port and the second port are used for being connected with the positive electrode or the negative electrode of a power supply, the first driving circuit and the second driving circuit are used for driving the switch, the first holding circuit and the second holding circuit are used for enabling the switch to be in a self-holding state, the time control regulating circuit controls the output of the safety switch circuit by limiting the time difference of the first port and the second port which are connected with the power supply in sequence, the first driving circuit, the second port, the time control regulating circuit and the second holding circuit are connected with each other, the first driving circuit is connected with the second driving circuit through the first port and the second driving circuit, meanwhile, the time difference of the first port and the second port which are connected with the power supply is limited, misoperation is avoided, and safety is high.

Inventors

  • XIAO ZHIBIN
  • SU BINGBO
  • LIN ZHONGYONG

Assignees

  • 厦门宏发电声股份有限公司

Dates

Publication Date
20260512
Application Date
20250407

Claims (12)

  1. 1. The safety switch circuit is characterized by comprising a switch, a first port and a second port which are used for connecting an anode or a cathode of a power supply, a first driving circuit and a second driving circuit which are used for driving the switch, a first holding circuit and a second holding circuit which are used for enabling the switch to be in a self-holding state, and a time control regulating circuit, wherein the time control regulating circuit controls the output of the safety switch circuit by limiting the time difference that the first port and the second port are connected with the power supply in sequence, the first driving circuit, the second port, the time control regulating circuit and the second holding circuit are connected with each other, and the first driving circuit is connected with the second driving circuit through the first port and the second driving circuit, and meanwhile, the first driving circuit is also connected with the second driving circuit through the first holding circuit.
  2. 2. The safety switching circuit according to claim 1, wherein the time control adjusting circuit comprises a delay capacitor, a MOS transistor and a triode, one end of the delay capacitor is connected with the second port, the grid electrode of the MOS transistor and the base electrode of the triode, the drain electrode of the MOS transistor is connected with the second driving circuit, the source electrode of the MOS transistor is connected with the collector electrode of the triode, and the other end of the delay capacitor is connected with the emitter electrode of the triode, the second holding circuit and the first driving circuit.
  3. 3. The safety switching circuit according to claim 2, wherein the time control adjusting circuit includes two of the transistors, wherein a collector of one of the transistors is connected to a source of the MOS transistor, an emitter is connected to a collector of the other transistor, and an emitter of the other transistor is grounded and connected to the second holding circuit and the first driving circuit.
  4. 4. The safety switching circuit according to claim 2 or 3, further comprising a first diode, a normally-closed switch, a second diode and a first resistor, wherein the first driving circuit, the time control adjusting circuit and the second holding circuit are all connected with the second port through the first diode, and the second port is connected with one end of the delay capacitor after passing through the normally-closed switch, the second diode and the first resistor which are sequentially connected in series.
  5. 5. The safety switching circuit of claim 4, wherein the switch comprises a relay and the normally closed switch comprises a relay normally closed contact.
  6. 6. The safety switching circuit according to claim 5, further comprising a power supply circuit, a control switch, a third port connected to an anode of the power supply circuit, and a fourth port connected to a cathode of the power supply circuit, wherein the control switch includes a first control switch and a second control switch, the second port is connected to the third port, the fourth port is connected to the first port when the first control switch is pressed down alone, the first port is connected to the third port, the second port is disconnected from the third port when the second control switch is pressed down alone, the first port and the fourth port are disconnected, and the second port is connected to the fourth port when the first control switch is pressed down alone, and the first port is connected to the fourth port.
  7. 7. The safety switching circuit according to claim 6, further comprising an output circuit for outputting a signal, the output circuit including a contact of the relay, the power supply circuit including a rectifier diode, a thermistor, a fuse, and a filter capacitor, a power supply positive electrode being connected to the third port through the rectifier diode, the thermistor, and the fuse connected in series in this order, the third port being connected to the fourth port through the filter capacitor.
  8. 8. The safety switching circuit according to claim 5, wherein the first driving circuit comprises a normally closed contact of a first relay, a first zener diode, a third diode and a fourth diode, a charging loop diode and a second relay coil which are sequentially connected in series, wherein the second relay coil is connected with the fourth diode in parallel, the anode of the charging loop diode is connected with the anode of the fourth diode, the cathode of the charging loop diode is connected with the cathode of the first zener diode, the anode of the first zener diode is connected with the anode of the third diode, and the cathode of the third diode is connected with the cathode of the fourth diode.
  9. 9. The safety switching circuit according to claim 8, wherein the first holding circuit comprises a second zener diode, a fifth diode and a second normally open relay contact connected in series in sequence, wherein a negative electrode of the second zener diode is connected with the first port and the first normally closed relay contact, a positive electrode of the second zener diode is connected with a positive electrode of the fifth diode, and a second normally open relay contact is connected with a negative electrode of the fourth diode and the second relay coil.
  10. 10. The safety switching circuit according to claim 5, wherein the second driving circuit comprises a first triode, a second triode, a sixth diode and a first relay coil connected in parallel with the sixth diode, an emitter of the first triode is connected with the first port, the first driving circuit and the first holding circuit, a base of the first triode is connected with the first holding circuit, a collector of the first triode is connected with an emitter of the second triode and a cathode of the sixth diode, an emitter of the second triode is connected with a base of the second triode through a resistor, a collector of the second triode is connected with a gate of the MOS transistor, and a drain of the MOS transistor is connected with the sixth diode, the second holding circuit and a base of the second triode through a resistor.
  11. 11. The safety switching circuit according to claim 5, wherein the second holding circuit comprises a normally open contact of the first relay, a third zener diode, and a seventh diode connected in series, the anode of the third zener diode being connected to the anode of the seventh diode.
  12. 12. The safety switching circuit according to claim 10, wherein a base electrode of the first triode is connected with the first holding circuit through a current limiting resistor, a pull-up resistor is arranged between an emitter electrode of the first triode and the current limiting resistor, a gate electrode of the MOS transistor and a base electrode of the triode are connected to one end of the delay capacitor through a diode and a resistor, a bypass capacitor is arranged between the gate electrode and the source electrode of the MOS transistor, a pull-down resistor is arranged between the gate electrode and the ground, a bypass capacitor and the pull-down resistor are connected in parallel between the base electrode of the triode and the ground, and a collector electrode of the second triode is connected to the gate electrode of the MOS transistor through a resistor.

Description

Safety switch circuit Technical Field The utility model belongs to the technical field of industrial automation control, and particularly relates to a safety switch circuit. Background In industrial production, a two-hand synchronous control device is an important device for ensuring operation safety. Although the conventional two-hand button control device improves safety to some extent, there is a safety hazard such as when one button is pressed for a long time, the pressing of the other button can activate the device, which may cause injury to the operator. Furthermore, many businesses do not use standard two-hand synchronization modules for cost or technical reasons, but simply connect two buttons in series, which greatly reduces the safety protection effect. Disclosure of utility model In order to solve the problems in the prior art, the application provides a safety switch circuit, wherein the control of two hands is connected with the start and stop of equipment, so that an operator is forced to use the two hands to control the equipment at the same time, the equipment can be started normally, and the two hands of the operator have no opportunity to enter a dangerous area, thereby meeting the safety requirement. The utility model adopts the following technical scheme: The safety switch circuit comprises a switch, a first port and a second port which are used for connecting an anode or a cathode of a power supply, a first driving circuit and a second driving circuit which are used for driving the switch, a first holding circuit and a second holding circuit which are used for enabling the switch to be in a self-holding state, and a time control regulating circuit, wherein the time control regulating circuit controls the output of the safety switch circuit by limiting the time difference of the first port and the second port which are connected with the power supply in sequence, the first driving circuit, the second port, the time control regulating circuit and the second holding circuit are connected with each other, and the first driving circuit is connected with the second driving circuit through the first holding circuit while being connected with the time control regulating circuit through the first port and the second driving circuit. The scheme has the advantages that the whole circuit structure is simple, the manufacturing and the maintenance are convenient, the cost is reduced, the reliability is improved, the two hands are required to operate synchronously, namely, the first port and the second port are connected with corresponding power supplies, the operation time meets the condition of the time control regulating circuit, the safety switch circuit can be used for outputting, the dangerous situation caused by misoperation or accidental triggering of one hand can be avoided, and the safety of operators and equipment is effectively ensured. Preferably, the time control regulating circuit comprises a delay capacitor, a MOS transistor and a triode, wherein one end of the delay capacitor is connected with the second port, the grid electrode of the MOS transistor and the base electrode of the triode, the drain electrode of the MOS transistor is connected with the second driving circuit, the source electrode of the MOS transistor is connected with the collector electrode of the triode, and the other end of the delay capacitor is connected with the emitting electrode of the triode, the second holding circuit and the first driving circuit. The common cause failure problem of the system is considered by using the MOS transistor and the triode, and the stability of the system is enhanced through the heterogeneous form Further preferably, the time control adjusting circuit includes two triodes, wherein a collector of one of the triodes is connected with a source of the MOS transistor, an emitter of the other one of the triodes is connected with a collector of the other one of the triodes, and an emitter of the other one of the triodes is grounded and connected with the second holding circuit and the first driving circuit. When a single triode is in fault short circuit, the other triode can still play a role in stopping, and the stability of the safety switch circuit is improved. Still preferably, the circuit further comprises a first diode, a normally closed switch, a second diode and a first resistor, wherein the first driving circuit, the time control adjusting circuit and the second holding circuit are connected with the second port through the first diode, and the second port is connected with one end of the delay capacitor after passing through the normally closed switch, the second diode and the first resistor which are sequentially connected in series. The first diode prevents reverse current flow, protects elements in the first driving circuit, the time control adjusting circuit and the second holding circuit from being damaged by reverse voltage, improves stability and reliability of the circui