A two-out-of-three voting control circuit

Abstract

The present invention discloses a three-out-of-two voting control circuit, which receives three passive switch quantity signals, and outputs one passive switch quantity signal after logic processing by the voting circuit; when any two or more of the three passive switch quantity signals are valid, the voting signal can be output. The present invention can effectively perform three-out-of-two voting, and compared with the relay voting circuit, it has the advantages of less wiring, fewer fault points, no need for additional program processing, simple circuit structure, low application cost, etc.

Description

Technical Field

[0001] The invention belongs to an emergency diesel generator set control system in a special application field, and specifically relates to a two-out-of-three voting control circuit. Background Art

[0002] The emergency generator set starting control system refers to a control system that automatically starts the emergency generator set for emergency power supply when the power system loses power; it is mainly used in places with high requirements for power supply reliability.

[0003] Emergency diesel generator sets in special application fields have high requirements on the safety protection function of the control system. In order to avoid the phenomenon that the protection function of the control system is falsely triggered due to erroneous signals, the control system adopts a two-out-of-three judgment strategy for the acquisition of emergency start-up, overspeed and other signals.

[0004] If the emergency generator control system involves three-out-of-two voting output signals, almost all of them adopt relay voting. The principle is to use three relays, each relay has at least two sets of contacts, and any two relays are connected in series and then in parallel to form a three-out-of-two voting circuit; however, this three-out-of-two voting circuit has many external wiring and many fault points. Summary of the invention

[0005] The purpose of the present invention is to provide a three-out-of-two voting control circuit, which can effectively solve the problems of multiple external wiring and multiple fault points in the three-out-of-two voting circuit of the relay, and is easy to install, operate and maintain, reduces the workload of wiring and checking, and has a modular design that facilitates later maintenance.

[0006] The present invention adopts the following technical scheme to achieve the above-mentioned purpose:

[0007] A three-out-of-two voting control circuit, the three-out-of-two voting control circuit has a signal acquisition and voting module; the signal acquisition and voting module has three resistors R1, R2, and R3 with the same resistance and connected in parallel; three switches S1, S2, and S3 are respectively connected in parallel to the R1, R2, and R3, that is, the switch S1 is set corresponding to the resistor R1, the switch S2 is set corresponding to the resistor R2, and the switch S3 is set corresponding to the resistor R3; one end of the R1, R2, and R3 is connected to a power supply, and the other end is connected in series with a resistor R4 and grounded to form a loop; the resistance value of the resistor R4 is the same as the resistance value of the resistors R1, R2, and R3; the signal acquisition and voting module also includes a comparator LM393D; the in-phase input end of the comparator LM393D is connected in series between the resistors R3 and R4 through a resistor R5 to detect the voltage between R3 and R4; the inverting input section of the comparator LM393D is connected to the power supply through a resistor R6, And grounded through R7 to detect the voltage between R6 and R7; the comparator LM393D is used to compare the voltage between R3 and R4 with the voltage between R6 and R7; a pull-up resistor R8 is set at the output end of the comparator LM393D, when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor R8; the pull-up resistor R8 is electrically connected to the drive circuit.

[0008] The driving circuit comprises a resistor R10, an LED, a resistor R9, a relay K1 and a MOS tube 2N6659; the resistor R9 and the relay K1 are connected in series and in parallel with the resistor R10 and the LED; the resistor R9 and the relay K1 are connected in series and then connected in parallel with the resistor R10 and the LED in series, and the overall circuit after the two circuits are connected in parallel is then connected in series with the MOS tube 2N6659; when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, 2N6659 is turned on, LED1 is lit, and the K1 relay contact is closed; when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor, 2N6659 is turned off, LED1 is extinguished, and the K1 relay contact is disconnected.

[0009] The present invention aims at a two-out-of-three voting output circuit involved in a control system of an emergency generator set. A series-parallel circuit is formed by resistors and switches, so that when different numbers of switches are closed, the same-phase input terminal of the comparator has corresponding voltages respectively; the effective number of switches is judged by the voltage comparison result, thereby realizing a two-out-of-three voting function. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the accompanying drawings.

[0012] like Figure 1 As shown, a three-out-of-two voting control circuit has a signal acquisition and voting module; the signal acquisition and voting module has three resistors R1, R2, and R3 with the same resistance and connected in parallel; three switches S1, S2, and S3 are respectively connected in parallel to the R1, R2, and R3, that is, the switch S1 is set corresponding to the resistor R1, the switch S2 is set corresponding to the resistor R2, and the switch S3 is set corresponding to the resistor R3; one end of the R1, R2, and R3 is connected to the power supply, and the other end is connected in series with the resistor R4 and grounded to form a loop; the resistance value of the resistor R4 is the same as the resistance value of the resistors R1, R2, and R3; the signal acquisition and voting module also includes a comparator LM393D; the non-inverting input end of the comparator LM393D is connected in series between the resistors R3 and R4 through the resistor R5 to detect the voltage between R3 and R4; the inverting input section of the comparator LM393D is connected to the power supply through the resistor R6, And grounded through R7 to detect the voltage between R6 and R7; the comparator LM393D is used to compare the voltage between R3 and R4 with the voltage between R6 and R7; a pull-up resistor R8 is set at the output end of the comparator LM393D, when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor R8; the pull-up resistor R8 is electrically connected to the drive circuit.

[0013] The driving circuit comprises a resistor R10, an LED, a resistor R9, a relay K1 and a MOS tube 2N6659; the resistor R9 and the relay K1 are connected in series and then connected in parallel with the resistor R10 and the LED connected in series, and the overall circuit after the two circuits are connected in parallel is then connected in series with the MOS tube 2N6659; when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, 2N6659 is turned on, LED1 lights up, and the K1 relay contact is closed; when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor, 2N6659 is turned off, LED1 goes out, and the K1 relay contact is disconnected.

[0014] Comparator LM393D inverting input voltage .

[0015] When all three switches S1, S2 and S3 are disconnected .

[0016] When two of the three switches S1, S2, and S3 are open and one is closed .

[0017] When one of the three switches S1, S2, and S3 is open and the other two are closed .

[0018] In summary, when the number of closed switches among the three switches is greater than or equal to two ,LM393D outputs a high level through the pull-up resistor, the back-end drive circuit, LED1 lights up, and the K1 relay contact closes; when the number of closed switches among the three switches is less than two , LM393D outputs a low level through the pull-up resistor, 2N6659 and the back-end drive circuit do not work, LED1 goes out, and the K1 relay contacts are disconnected.

[0019] When all three switches S1, S2, and S3 are closed .

Claims

1. A two-out-of-three voting control circuit, characterized in that: The three-out-of-two voting control circuit has a signal acquisition and voting module; the signal acquisition and voting module has three resistors R1, R2, and R3 with the same resistance and connected in parallel; three switches S1, S2, and S3 are respectively connected in parallel to the R1, R2, and R3, that is, the switch S1 is set corresponding to the resistor R1, the switch S2 is set corresponding to the resistor R2, and the switch S3 is set corresponding to the resistor R3; one end of the R1, R2, and R3 is connected to the power supply, and the other end is connected in series with the resistor R4 and grounded to form a loop; the resistance value of the resistor R4 is the same as the resistance value of the resistors R1, R2, and R3; the signal acquisition and voting module also includes a comparator LM393D; the in-phase input end of the comparator LM393D is connected in series between the resistors R3 and R4 through the resistor R5 to detect the voltage between R3 and R4; the inverting input section of the comparator LM393D is connected to the power supply through the resistor R6, And grounded through R7 to detect the voltage between R6 and R7; the comparator LM393D is used to compare the voltage between R3 and R4 with the voltage between R6 and R7; a pull-up resistor R8 is set at the output end of the comparator LM393D, when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor R8; the pull-up resistor R8 is electrically connected to the drive circuit.

2. A two-out-of-three voting control circuit as claimed in claim 1, characterized in that: The driving circuit comprises a resistor R10, an LED, a resistor R9, a relay K1 and a MOS tube 2N6659; the resistor R9 and the relay K1 are connected in series and then connected in parallel with the resistor R10 and the LED in series, and the overall circuit after the two circuits are connected in parallel is then connected in series with the MOS tube 2N6659; when the voltage between R3 and R4 is greater than the voltage between R6 and R7, the comparator LM393D outputs a high level through the pull-up resistor R8, 2N6659 is turned on, LED1 lights up, and the K1 relay contact is closed; when the voltage between R3 and R4 is less than the voltage between R6 and R7, the comparator LM393D outputs a low level through the pull-up resistor, 2N6659 is turned off, LED1 goes out, and the K1 relay contact is disconnected.

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