Quadruple high-reliability safety relay

Abstract

The invention belongs to the technical field of safety relays, and particularly relates to a quadruple high-reliability safety relay which comprises an external power supply end, a power supply protection circuit, a relay protection circuit and an RS2401 output circuit. The relay protection circuit comprises a K1 relay protection circuit, a K2 relay protection circuit, a K3 relay protection circuit and a K4 relay protection circuit. The mode that every two relays are connected in parallel and then connected in series is adopted, and even if the relay in a certain loop is damaged, normal work of the whole loop cannot be affected. Therefore, the reliability of the quadruple safety relay is improved, the usability of the quadruple safety relay is improved, and the stable operation condition of a loop is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of safety relays, and in particular to a quadruple high-reliability safety relay. Background Art

[0002] Safety relays are composed of several relays and circuits in order to complement each other's abnormal defects and achieve complete relay functions with correct and low false operation. The lower the error and failure value, the higher the safety factor. Therefore, a variety of safety relays need to be designed to protect different levels of machinery. The main goal is to protect machine operators exposed to different levels of danger.

[0003] Conventional safety relays use a combination of contacts in series to achieve effective execution of safety actions to increase the reliability of the SIL circuit. However, when any of the relays fails, the entire circuit will be disconnected, increasing the probability of false operation of the field circuit. Summary of the invention

[0004] The purpose of the present invention is to provide a quadruple high-reliability safety relay to solve the problem of the conventional safety relay proposed in the above background technology that when any one of the relays fails, the entire circuit will be disconnected, increasing the probability of malfunction of the field circuit.

[0005] To achieve the above object, the present invention provides the following technical solution: a quadruple high-reliability safety relay, comprising:

[0006] External power supply terminal, power supply protection circuit, relay protection circuit and RS2401 output circuit;

[0007] Wherein, the external power supply end is connected to the power supply protection circuit, and the relay protection circuit includes a K1 relay protection circuit, a K2 relay protection circuit, a K3 relay protection circuit and a K4 relay protection circuit;

[0008] The K1 relay protection circuit, K2 relay protection circuit, K3 relay protection circuit and K4 relay protection circuit are respectively output and connected to the K1 relay coil, K2 relay coil, K3 relay coil and K4 relay coil, and the K1 relay coil, K2 relay coil, K3 relay coil and K4 relay coil are respectively connected to the K1 common terminal, K2 common terminal, K3 common terminal and K4 common terminal;

[0009] The K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal are provided with corresponding K1 normally open terminal, K2 normally open terminal, K3 normally open terminal, and K4 normally open terminal. The K1 common terminal is connected to the K2 common terminal, and the K1 normally open terminal and K2 normally open terminal are connected to the K3 common terminal and K4 common terminal.

[0010] The RS2401 output circuit includes a sampling resistor, a fuse and a load power supply, the load power supply is connected to the fuse and the load, the fuse is connected to the common end of K1 and the common end of K2, the common end of K3 and the common end of K4 are connected to the sampling resistor, and the sampling resistor is connected to the load.

[0011] Preferably, the power supply protection circuit includes a slow-blow fuse F1 having one end connected to the external power supply end, the other end of the slow-blow fuse F1 is connected to one end of the TVS tube and the resettable fuse FK1, the other end of the resettable fuse FK1 is connected to the positive electrodes of the diodes D1 and D2, the negative electrodes of the diodes D1 and D2 are connected to one end of the capacitors C1 and C2, one end of the resistor R1, and one end of the capacitors C9 and C10, the other ends of the capacitors C1 and C2 are connected to one end of the capacitors C3 and C4, the other end of the resistor R1 is connected to the resistor R2, the other end of the resistor R2 is connected to the resistor R3, the other end of the resistor R3 is connected to the positive electrode of LD1, the negative electrode of LD1, the other ends of the capacitors C3 and C4, and the other end of the TVS tube are connected to the other end of the external power supply end;

[0012] One end of the capacitors C9 and C10 is also connected to the 4th and 5th pins of the buck chip U0, and the other ends of the capacitors C9 and C10 are connected to the 2nd and 3rd pins of the buck chip U0, the other end of the external power supply end, and one end of the capacitor C13. The 6th pin of the buck chip U0 is connected to one end of the inductor LH1 and one end of the capacitor C14. The other end of the capacitor C14 is connected to the 1st pin of the buck chip U0. The 3rd pin of the buck chip U0 is also connected to one end of the resistor R17, one end of the resistor R16, and one end of the capacitor C12. The other end of the resistor R17 is connected to the 2nd pin of the buck chip U0. One end of the resistor R16, one end of the capacitor C12, the other end of the capacitor C13, and the other end of the inductor LH1 are connected;

[0013] Both ends of the capacitor C13 are connected to the relay protection circuit.

[0014] Preferably, the K1 relay protection circuit includes a transistor Q1 and a resistor R4, one end of the capacitor C13 is connected to one end of the resistor R4 and the emitter of the transistor Q1, the base of the transistor Q1 is connected to the other end of the resistor R4 and the emitter of the transistor Q2, the collector of the transistor Q1 and the base of the transistor Q2 are both connected to one end of the resistor R5, the other end of the resistor R5 is connected to the resistor R6, DD1 is connected between the other end of the resistor R6 and the collector of the transistor Q2, a capacitor C5 is connected in parallel to DD1, and both ends of the capacitor C5 are connected to both ends of the K1 relay coil.

[0015] Preferably, the K2 relay protection circuit includes a transistor Q3 and a resistor R7, one end of the capacitor C13 is connected to one end of the resistor R7 and the emitter of the transistor Q3, the base of the transistor Q3 is connected to the other end of the resistor R7 and the emitter of the transistor Q4, the collector of the transistor Q3 and the base of the transistor Q4 are both connected to one end of the resistor R8, the other end of the resistor R8 is connected to the resistor R9, DD2 is connected between the other end of the resistor R9 and the collector of the transistor Q2, a capacitor C6 is connected in parallel to DD2, and both ends of the capacitor C6 are connected to both ends of the K2 relay coil.

[0016] Preferably, the K3 relay protection circuit includes a transistor Q5 and a resistor R10, one end of the capacitor C13 is connected to one end of the resistor R10 and the emitter of the transistor Q5, the base of the transistor Q5 is connected to the other end of the resistor R10 and the emitter of the transistor Q6, the collector of the transistor Q5 and the base of the transistor Q6 are both connected to one end of the resistor R11, the other end of the resistor R11 is connected to the resistor R12, DD3 is connected between the other end of the resistor R12 and the collector of the transistor Q6, a capacitor C7 is connected in parallel to DD3, and both ends of the capacitor C7 are connected to both ends of the K3 relay coil.

[0017] Preferably, the K4 relay protection circuit includes a transistor Q7 and a resistor R13, one end of the capacitor C13 is connected to one end of the resistor R13 and the emitter of the transistor Q7, the base of the transistor Q7 is connected to the other end of the resistor R13 and the emitter of the transistor Q8, the collector of the transistor Q7 and the base of the transistor Q8 are both connected to one end of the resistor R14, the other end of the resistor R14 is connected to the resistor R15, DD4 is connected between the other end of the resistor R15 and the collector of the transistor Q8, the other end of the resistor R15 is also connected to the other end of the capacitor C13, a capacitor C8 is connected in parallel to DD4, and both ends of the capacitor C8 are connected to both ends of the K4 relay coil.

[0018] Preferably, the K1 relay coil, K2 relay coil, K3 relay coil, and K4 relay coil correspond to the positions of the K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal, respectively.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The sampling method of connecting two relays in parallel and then in series is adopted. Even if a relay in a circuit is damaged, it should not affect the normal operation of the entire circuit. This not only improves the reliability and availability of the quadruple safety relay, but also ensures the stable operation of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the circuit principle diagram of the present invention;

[0022] Figure 2 This is a power supply protection circuit diagram of the present invention;

[0023] Figure 3 This is the K1 relay protection circuit diagram of the present invention;

[0024] Figure 4 This is the K2 relay protection circuit diagram of the present invention;

[0025] Figure 5 This is the K3 relay protection circuit diagram of the present invention;

[0026] Figure 6 This is the K4 relay protection circuit diagram of the present invention;

[0027] Figure 7 It is the RS2401 output circuit diagram of the present invention;

[0028] Figure 8 It is a system logic block diagram of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] Embodiment 1:

[0032] See also Figure 1-8 ,The present invention provides a technical solution: a quadruple high-reliability safety relay, comprising: an external power supply terminal, a power supply protection circuit, a relay protection circuit and an RS2401 output circuit;

[0033] Wherein, the external power supply end is connected to the power supply protection circuit, and the relay protection circuit includes a K1 relay protection circuit, a K2 relay protection circuit, a K3 relay protection circuit and a K4 relay protection circuit; the K1 relay protection circuit, the K2 relay protection circuit, the K3 relay protection circuit and the K4 relay protection circuit are respectively output-connected to the K1 relay coil, the K2 relay coil, the K3 relay coil and the K4 relay coil, and the K1 relay coil, the K2 relay coil, the K3 relay coil and the K4 relay coil are respectively connected to the K1 common end, the K2 common end, the K3 common end, K4 common terminal; the K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal are provided with corresponding K1 normally open terminal, K2 normally open terminal, K3 normally open terminal, and K4 normally open terminal, the K1 common terminal is connected to the K2 common terminal, and the K1 normally open terminal and K2 normally open terminal are connected to the K3 common terminal and K4 common terminal; the RS2401 output circuit includes a sampling resistor, a fuse and a load power supply, the load power supply is connected to the fuse and the load, the fuse is connected to the K1 common terminal and K2 common terminal, the K3 common terminal and K4 common terminal are connected to the sampling resistor, and the sampling resistor is connected to the load.

[0034] Embodiment 2:

[0035] See also Figure 1 , 2 The present invention provides a technical solution: the power supply protection circuit includes a slow-blow fuse F1 connected to an external power supply end at one end, the other end of the slow-blow fuse F1 is connected to one end of a TVS tube and a resettable fuse FK1, the other end of the resettable fuse FK1 is connected to the positive electrodes of diodes D1 and D2, the negative electrodes of diodes D1 and D2 are connected to one end of capacitors C1 and C2, one end of a resistor R1, and one end of capacitors C9 and C10, the other ends of capacitors C1 and C2 are connected to one end of capacitors C3 and C4, the other end of resistor R1 is connected to resistor R2, the other end of resistor R2 is connected to resistor R3, the other end of resistor R3 is connected to the positive electrode of LD1, the negative electrode of LD1, the other ends of capacitors C3 and C4, and the other end of the TVS tube are connected to the other end of the external power supply end;

[0036] One end of the capacitors C9 and C10 is also connected to pins 4 and 5 of the buck chip U0, and the other ends of the capacitors C9 and C10 are connected to pins 2 and 3 of the buck chip U0, the other end of the external power supply end, and one end of the capacitor C13. Pin 6 of the buck chip U0 is connected to one end of the inductor LH1 and one end of the capacitor C14. The other end of the capacitor C14 is connected to pin 1 of the buck chip U0. Pin 3 of the buck chip U0 is also connected to one end of the resistor R17, one end of the resistor R16, and one end of the capacitor C12. The other end of the resistor R17 is connected to pin 2 of the buck chip U0, one end of the resistor R16, one end of the capacitor C12, the other end of the capacitor C13, and the other end of the inductor LH1 are connected; both ends of the capacitor C13 are connected to the relay protection circuit.

[0037] Analysis of the above content:

[0038] At the power input end, protection components such as slow-blow fuses, TVS tubes, and self-recovery fuses are designed. They play a role in overvoltage and overcurrent protection, and EMC electromagnetic compatibility design. Meet the over-limit protection design. After the power passes through the protection circuit, the filter capacitor is connected in parallel to make the power more stable. At the same time, a group of power light circuits are connected in parallel. The green indicator light indicates whether the power is powered on or off. The input voltage (13-35V) passes through the power chip SGM61410 to control the voltage output to 12V, and power the internal relay. The safety relay is closed and output. The SGM61410 peripheral circuit consists of input and output voltage stabilization capacitors and voltage divider resistors.

[0039] Device and function analysis:

[0040] F1 is a 1A slow-blow fuse, and TV1 is a SMBJ36V TVS tube, which provides EMC protection for the power port and overvoltage protection for the power supply system.

[0041] analyze:

[0042] a: When F1 is short-circuited, the output of the safety relay is not affected. The load circuit works normally. When F1 is open-circuited, the circuit loses power and the safety relay output is disconnected.

[0043] b: TV1 failure mode is short circuit. When short circuit occurs, FI is disconnected and the safety relay output is disconnected.

[0044] FK is a self-recovery fuse, the main function of which is to monitor the short circuit of the input channel, with a rated value of 200mA60V.

[0045] Analysis: When FK is short-circuited, the output of the safety relay is not affected and the load circuit operates normally.

[0046] When FK fails, the circuit loses power and the safety relay output is disconnected.

[0047] D1 D2 diode model SS16, parameter maximum current 1A, reverse voltage 60V, unidirectional conduction. Two diodes are connected in parallel to play a redundant role and increase the current in the loop.

[0048] analyze:

[0049] a: D1 is open or short circuited. It does not affect the output of the safety relay. The load circuit operates normally.

[0050] b: D2 is open or short-circuited. It does not affect the output of the safety relay. The load circuit operates normally.

[0051] c: D1 and D2 are connected in parallel to improve circuit reliability. The probability of short circuit or open circuit is negligible.

[0052] Capacitors C1, C2 are connected in parallel, C3, C4 are connected in parallel, and in series, which play the role of voltage stabilization and filtering.

[0053] analyze:

[0054] a: C1, C2 or C3, C4 are open circuit, which does not affect the output of the safety relay. The load circuit operates normally.

[0055] b: Short circuit of C1, C2 or C3, C4 does not affect the output of the safety relay.

[0056] c: Use C1 / C2 and C3 / C4 in series to improve the reliability of the circuit. The probability of short circuit or open circuit is negligible.

[0057] Resistors R1, R2, R3 and LD1 form a power indicator light circuit.

[0058] analyze:

[0059] If any device in the indicator light circuit is broken, the LED light will go out, but it will not affect the output of the safety relay.

[0060] Capacitors C9C10C12C13 belong to the peripheral circuit of the buck chip and have functions such as filtering and decoupling. Component failure will not affect the voltage output.

[0061] Resistors R13 and R14 are voltage divider output resistors. If the device fails, the voltage output value will change, affecting the power supply of the relay and thus the output of the safety relay.

[0062] When the inductor LH1 is open, the internal relay loses power. The safety relay loses power. When short-circuited, the voltage output value decreases and the safety relay loses power.

[0063] Embodiment three:

[0064] See also Figure 1 , 3The present invention provides a technical solution: the K1 relay protection circuit includes a transistor Q1 and a resistor R4, one end of the capacitor C13 is connected to one end of the resistor R4 and the emitter of the transistor Q1, the base of the transistor Q1 is connected to the other end of the resistor R4 and the emitter of the transistor Q2, the collector of the transistor Q1 and the base of the transistor Q2 are both connected to one end of the resistor R5, the other end of the resistor R5 is connected to the resistor R6, DD1 is connected between the other end of the resistor R6 and the collector of the transistor Q2, a capacitor C5 is connected in parallel to the DD1, and both ends of the capacitor C5 are connected to both ends of the K1 relay coil.

[0065] Analysis of the above content: When this circuit works normally, Q1 is cut off, Q2 is turned on, and they form a switching circuit with R4R5R6. The relay is energized and the safety relay is closed.

[0066] The short circuit of R4R5R6 resistors does not affect the output of the safety relay. ...

[0067] When Q2 is short-circuited, K1 is energized, and the safety relay is energized and closed. When Q2 is open-circuited, K1 loses power, and the safety relay loses power and opens.

[0068] DD1 and C5 form a freewheeling circuit, providing a reverse consumption path for the K1 relay line. When short-circuited, overcurrent protection is activated. Q2 is turned off, Q1 is turned on, and R5R6 forms a path. The K1 relay loses power and the safety relay is safely disconnected.

[0069] Embodiment 4:

[0070] See also Figure 1 , 4 The present invention provides a technical solution: the K2 relay protection circuit includes a transistor Q3 and a resistor R7, one end of the capacitor C13 is connected to one end of the resistor R7 and the emitter of the transistor Q3, the base of the transistor Q3 is connected to the other end of the resistor R7 and the emitter of the transistor Q4, the collector of the transistor Q3 and the base of the transistor Q4 are both connected to one end of the resistor R8, the other end of the resistor R8 is connected to the resistor R9, DD2 is connected between the other end of the resistor R9 and the collector of the transistor Q2, a capacitor C6 is connected in parallel to DD2, and both ends of the capacitor C6 are connected to both ends of the K2 relay coil.

[0071] Analysis of the above content: When this circuit works normally, Q3 is cut off, Q4 is turned on, and forms a switching circuit with R7R8R9. The relay is energized and the safety relay is closed.

[0072] The short circuit of R7R8R9 resistors does not affect the output of the safety relay. ...

[0073] When Q4 is short-circuited, K2 is energized, and the safety relay is energized and closed. When Q4 is open-circuited, K2 loses power, and the safety relay loses power and opens.

[0074] DD2 and C6 form a freewheeling circuit, providing a reverse consumption path for the K2 relay line. When short-circuited at the same time, overcurrent protection is activated. Q4 is turned off, Q3 is turned on, and R8R9 forms a path. The K2 relay loses power and the safety relay is disconnected.

[0075] Embodiment five:

[0076] See also Figure 1 , 5 The present invention provides a technical solution: the K3 relay protection circuit includes a transistor Q5 and a resistor R10, one end of the capacitor C13 is connected to one end of the resistor R10 and the emitter of the transistor Q5, the base of the transistor Q5 is connected to the other end of the resistor R10 and the emitter of the transistor Q6, the collector of the transistor Q5 and the base of the transistor Q6 are both connected to one end of the resistor R11, the other end of the resistor R11 is connected to the resistor R12, DD3 is connected between the other end of the resistor R12 and the collector of the transistor Q6, a capacitor C7 is connected in parallel to the DD3, and both ends of the capacitor C7 are connected to both ends of the K3 relay coil.

[0077] Analysis of the above content: When this circuit works normally, Q5 is cut off, Q6 is turned on, and R10R11R12 form a switching circuit. The relay is energized and the safety relay is closed.

[0078] The short circuit of R10R11R12 resistors does not affect the output of the safety relay. The short circuit of R10R11R12 will cause Q6 to be cut off, K3 relay will lose power, and the safety relay will lose power and disconnect.

[0079] When Q6 is short-circuited, K3 is energized, and the safety relay is energized and closed. When Q6 is open-circuited, K3 loses power, and the safety relay loses power and opens.

[0080] DD3 and C15 form a freewheeling circuit, providing a reverse consumption path for the K3 relay line. When short-circuited at the same time, overcurrent protection is activated. Q6 is cut off, Q5 is turned on, and R11R12 forms a path. The K3 relay loses power and the safety relay is disconnected.

[0081] Embodiment six:

[0082] See also Figure 1 , 6The present invention provides a technical solution: the K4 relay protection circuit includes a transistor Q7 and a resistor R13, one end of the capacitor C13 is connected to one end of the resistor R13 and the emitter of the transistor Q7, the base of the transistor Q7 is connected to the other end of the resistor R13 and the emitter of the transistor Q8, the collector of the transistor Q7 and the base of the transistor Q8 are both connected to one end of the resistor R14, the other end of the resistor R14 is connected to the resistor R15, DD4 is connected between the other end of the resistor R15 and the collector of the transistor Q8, the other end of the resistor R15 is also connected to the other end of the capacitor C13, the capacitor C8 is connected in parallel to the DD4, and the two ends of the capacitor C8 are connected to the two ends of the K4 relay coil.

[0083] Analysis of the above content: When this circuit works normally, Q7 is cut off, Q8 is turned on, and they form a switching circuit with R13R14R15. The relay is energized and the safety relay is closed.

[0084] The short circuit of R13R14R15 resistors does not affect the output of the safety relay. ...

[0085] When Q8 is short-circuited, K4 is energized, and the safety relay is energized and closed. When Q8 is open-circuited, K4 loses power, and the safety relay loses power and opens.

[0086] DD4 and C8 form a freewheeling circuit, providing a reverse consumption path for the K4 relay line. When short-circuited at the same time, overcurrent protection is activated. Q8 is cut off, Q7 is turned on, and R14R15 forms a path. The K3 relay loses power and the safety relay is disconnected.

[0087] Embodiment seven:

[0088] See also Figure 1-8 The present invention provides a technical solution: the K1 relay coil, K2 relay coil, K3 relay coil, and K4 relay coil correspond to the positions of the K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal respectively.

[0089] In this way, when the K1 relay coil, the K2 relay coil, the K3 relay coil, and the K4 relay coil are energized, magnetic force is generated and corresponding adsorption can be achieved.

[0090] like Figure 7 As shown, K1 and K2 are connected in parallel, and K3 and K4 are connected in parallel. The two parallel connections are then output in series. K1, K2, K3, and K4 are normally energized and the contacts are closed. A 5A fuse is set at the input end of the load power supply. If the limit is exceeded, the fuse will be blown. Circuit analysis:

[0091] K1 k2, K3K4 are energized, and the safety relay is energized and closed. K1 k2 is connected in parallel, K3K4 is connected in parallel, and then in series. This method has no failure mode.

[0092] If the F1 (5A) fuse is broken, the safety relay will be disconnected due to power failure. If short-circuited, the output of the safety relay will not be affected.

[0093] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the claims involved.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A quadruple high reliability safety relay, characterized in that: include: External power supply terminal, power supply protection circuit, relay protection circuit and RS2401 output circuit; Wherein, the external power supply end is connected to the power supply protection circuit, and the relay protection circuit includes a K1 relay protection circuit, a K2 relay protection circuit, a K3 relay protection circuit and a K4 relay protection circuit; The K1 relay protection circuit, K2 relay protection circuit, K3 relay protection circuit and K4 relay protection circuit are respectively output and connected to the K1 relay coil, K2 relay coil, K3 relay coil and K4 relay coil, and the K1 relay coil, K2 relay coil, K3 relay coil and K4 relay coil are respectively connected to the K1 common terminal, K2 common terminal, K3 common terminal and K4 common terminal; The K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal are provided with corresponding K1 normally open terminal, K2 normally open terminal, K3 normally open terminal, and K4 normally open terminal. The K1 common terminal is connected to the K2 common terminal, and the K1 normally open terminal and K2 normally open terminal are connected to the K3 common terminal and K4 common terminal. The RS2401 output circuit includes a sampling resistor, a fuse and a load power supply, the load power supply is connected to the fuse and the load, the fuse is connected to the common end of K1 and the common end of K2, the common end of K3 and the common end of K4 are connected to the sampling resistor, and the sampling resistor is connected to the load.

2. A quadruple high reliability safety relay according to claim 1, characterized in that: The power supply protection circuit includes a slow-blow fuse F1 having one end connected to the external power supply end, the other end of the slow-blow fuse F1 is connected to one end of the TVS tube and the resettable fuse FK1, the other end of the resettable fuse FK1 is connected to the positive electrodes of the diodes D1 and D2, the negative electrodes of the diodes D1 and D2 are connected to one end of the capacitors C1 and C2, one end of the resistor R1, and one end of the capacitors C9 and C10, the other ends of the capacitors C1 and C2 are connected to one end of the capacitors C3 and C4, the other end of the resistor R1 is connected to the resistor R2, the other end of the resistor R2 is connected to the resistor R3, the other end of the resistor R3 is connected to the positive electrode of LD1, the negative electrode of LD1, the other ends of the capacitors C3 and C4, and the other end of the TVS tube are connected to the other end of the external power supply end; One end of the capacitors C9 and C10 is also connected to the 4th and 5th pins of the buck chip U0, and the other ends of the capacitors C9 and C10 are connected to the 2nd and 3rd pins of the buck chip U0, the other end of the external power supply end, and one end of the capacitor C13. The 6th pin of the buck chip U0 is connected to one end of the inductor LH1 and one end of the capacitor C14. The other end of the capacitor C14 is connected to the 1st pin of the buck chip U0. The 3rd pin of the buck chip U0 is also connected to one end of the resistor R17, one end of the resistor R16, and one end of the capacitor C12. The other end of the resistor R17 is connected to the 2nd pin of the buck chip U0. One end of the resistor R16, one end of the capacitor C12, the other end of the capacitor C13, and the other end of the inductor LH1 are connected; Both ends of the capacitor C13 are connected to the relay protection circuit.

3. A quadruple high reliability safety relay according to claim 2, characterized in that: The K1 relay protection circuit includes a transistor Q1 and a resistor R4. One end of the capacitor C13 is connected to one end of the resistor R4 and the emitter of the transistor Q1. The base of the transistor Q1 is connected to the other end of the resistor R4 and the emitter of the transistor Q2. The collector of the transistor Q1 and the base of the transistor Q2 are both connected to one end of the resistor R5. The other end of the resistor R5 is connected to the resistor R6. DD1 is connected between the other end of the resistor R6 and the collector of the transistor Q2. A capacitor C5 is connected in parallel to DD1. Both ends of the capacitor C5 are connected to both ends of the K1 relay coil.

4. A quadruple high reliability safety relay according to claim 3, characterized in that: The K2 relay protection circuit includes a transistor Q3 and a resistor R7. One end of the capacitor C13 is connected to one end of the resistor R7 and the emitter of the transistor Q3. The base of the transistor Q3 is connected to the other end of the resistor R7 and the emitter of the transistor Q4. The collector of the transistor Q3 and the base of the transistor Q4 are both connected to one end of the resistor R8. The other end of the resistor R8 is connected to the resistor R9. DD2 is connected between the other end of the resistor R9 and the collector of the transistor Q2. A capacitor C6 is connected in parallel to DD2. Both ends of the capacitor C6 are connected to both ends of the K2 relay coil.

5. A quadruple high reliability safety relay according to claim 4, characterized in that: The K3 relay protection circuit includes a transistor Q5 and a resistor R10. One end of the capacitor C13 is connected to one end of the resistor R10 and the emitter of the transistor Q5. The base of the transistor Q5 is connected to the other end of the resistor R10 and the emitter of the transistor Q6. The collector of the transistor Q5 and the base of the transistor Q6 are both connected to one end of the resistor R11. The other end of the resistor R11 is connected to the resistor R12. DD3 is connected between the other end of the resistor R12 and the collector of the transistor Q6. A capacitor C7 is connected in parallel to DD3, and both ends of the capacitor C7 are connected to both ends of the K3 relay coil.

6. A quadruple high reliability safety relay according to claim 5, characterized in that: The K4 relay protection circuit includes a transistor Q7 and a resistor R13. One end of the capacitor C13 is connected to one end of the resistor R13 and the emitter of the transistor Q7. The base of the transistor Q7 is connected to the other end of the resistor R13 and the emitter of the transistor Q8. The collector of the transistor Q7 and the base of the transistor Q8 are both connected to one end of the resistor R14. The other end of the resistor R14 is connected to the resistor R15. DD4 is connected between the other end of the resistor R15 and the collector of the transistor Q8. The other end of the resistor R15 is also connected to the other end of the capacitor C13. A capacitor C8 is connected in parallel to DD4. Both ends of the capacitor C8 are connected to both ends of the K4 relay coil.

7. The quadruple high reliability safety relay according to claim 1, characterized in that: The K1 relay coil, K2 relay coil, K3 relay coil, and K4 relay coil correspond to the positions of the K1 common terminal, K2 common terminal, K3 common terminal, and K4 common terminal, respectively.

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