CN213182381U - Dry contact control circuit capable of bidirectional protection - Google Patents

Abstract

The utility model discloses a dry contact control circuit capable of bidirectional protection, which comprises a code conversion module, a control module and a control module, wherein the code conversion module is used for converting TTL input signals which accord with conversion rules into single TTL output control signals; the signal conversion module is electrically connected with the code conversion module and is used for converting the single TTL output control signal output by the code conversion module into a control pulse; the isolation conversion module is electrically connected with the signal conversion module and is used for amplifying the control pulse output by the signal conversion module by multiple times, rectifying, filtering and stabilizing voltage and outputting stable MOS driving control voltage; the drive protection module is electrically connected with the isolation conversion module and is used for conducting and stopping control on the MOS tube pair transistors; and the MOS tube pair tube is formed by connecting two MOS tubes in series and is electrically connected with the drive protection module, so that bidirectional contactless control of a control loop is realized. The utility model discloses can solve the not enough of prior art, realize the two-way overcurrent short-circuit protection function in dry contact drive circuit.

Description

Dry contact control circuit capable of bidirectional protection

Technical Field

The utility model belongs to the technical field of industrial control, specifically a but two way protection's dry contact control circuit.

Background

In the industrial control field, in order to realize the contactless control loop, a large number of MOS tubes are adopted to replace an electric shock switch or a contactor such as a relay, and the like, wherein some MOS tubes are only used for level output control, power is supplied from the interior of a circuit, and the output mode is active output. The other mode is used as a passive mode switch, the MOS tube is only used as a controllable switch in a loop, but the MOS tube is generally provided with a reverse body diode, the single MOS tube is used as a switch in a directional mode, and if reverse voltage exists, the body diode is conducted, and the switching-off cannot be realized. In order to solve the unidirectional problem, two MOS transistors are connected in series back to realize bidirectional conduction and disconnection, which are commonly called dry contacts. However, the conventional dry contact driving circuit does not have a bidirectional overcurrent short-circuit protection function.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a but two-way protection's dry contact control circuit, can solve the not enough of prior art, realize the two-way overcurrent short-circuit protection function in dry contact drive circuit.

The content of the utility model comprises the following steps,

a dry contact control circuit with bidirectional protection comprises,

the coding conversion module is used for receiving TTL input signals with coding rules sent by a processor or a controller, and converting the TTL input signals which accord with the conversion rules into single TTL output control signals through logic analysis and rule judgment;

the signal conversion module is electrically connected with the code conversion module and is used for converting the single TTL output control signal output by the code conversion module into a control pulse;

the isolation conversion module is electrically connected with the signal conversion module and is used for amplifying the control pulse output by the signal conversion module by multiple times, rectifying, filtering and stabilizing voltage and outputting stable MOS driving control voltage;

the drive protection module is electrically connected with the isolation conversion module and used for conducting and stopping control on the MOS tube geminate transistors and realizing the protection on the abnormal current condition by monitoring the MOS tube geminate transistors current in real time;

and the MOS tube pair tube is formed by connecting two MOS tubes in series and is electrically connected with the drive protection module, so that bidirectional contactless control of a control loop is realized.

Preferably, the code conversion module is an SN74AHC1G08 one-way and gate chip.

Preferably, the signal conversion module is an SN6505 push-pull transformer driver, and a pin four of the SN74AHC1G08 one-way and gate chip is connected with a pin five of the SN6505 push-pull transformer driver.

Preferably, the isolation conversion module is formed by connecting a pulse transformer, a rectifier bridge and a voltage stabilizing and filtering unit in series, and a first pin, a second pin and a third pin of the SN6505 push-pull transformer driver are connected to the input side of the pulse transformer.

Preferably, the voltage stabilizing and filtering unit includes a first capacitor, a first resistor and a first voltage stabilizing diode connected in parallel to the output end of the rectifier bridge, and the output end of the rectifier bridge is further connected in series with a second resistor and a second voltage stabilizing diode.

Preferably, the driving protection module comprises two parallel MOS tube driving chips IR2127S, and pin one, pin two and pin four of the MOS tube driving chip IR2127S are respectively connected to the positive electrode of the rectifier bridge, between the second resistor and the second zener diode, and the negative electrode of the rectifier bridge.

Preferably, a fifth pin of the MOS transistor driver chip IR2127S is connected to a source of the MOS transistor, a fourth resistor is connected between the fifth pin and a sixth pin of the MOS transistor driver chip IR2127S, the sixth pin of the MOS transistor driver chip IR2127S is connected to a drain of the MOS transistor through a third resistor and a third ultrafast recovery diode connected in series, and a seventh pin of the MOS transistor driver chip IR2127S is connected to a gate of the MOS transistor through the fifth resistor.

Preferably, the sources of two of the MOS transistors are connected.

The utility model has the advantages that: the utility model provides a be applied to various industrial control output circuit, can realize two-way short-circuit protection's contactless dry contact control circuit, when can guaranteeing MOS pipe conduction, when the random direction of dry contact overflows or the short circuit, can both in time realize fast overflowing or short-circuit protection. The code conversion module effectively prevents the problem of single-point failure of single-input TTL level, and leads to safe guidance when an input control signal fails through two or more coding rules. Additionally, the utility model provides an keep apart the conversion function, drive signal has both realized the signal isolation transmission after through pulse transformer, also provides the energy as the power supply of back stage circuit simultaneously, in case the input signal became invalid, the whole electricity consumptions of drive protection module and the MOS pipe circuit of whole back stage for during turn-off control, the MOS pipe can thoroughly rapid turn-off, the direction is safe moreover.

Drawings

Fig. 1 is a schematic diagram of the present invention.

Fig. 2 is a flowchart of the operation of the transcoding module of the present invention.

Fig. 3 is a schematic diagram of the middle isolation conversion module of the present invention.

Fig. 4 is a flowchart of the operation of the middle driving protection module of the present invention.

Fig. 5 is a circuit diagram of the present invention.

Detailed Description

A dry contact control circuit with bidirectional protection comprises,

the code conversion module 1 is used for receiving TTL input signals with a code rule sent by a processor or a controller, and converting the TTL input signals which accord with the conversion rule into single TTL output control signals through logic analysis and rule judgment;

the signal conversion module 2 is electrically connected with the code conversion module 1 and is used for converting the single TTL output control signal output by the code conversion module 1 into a control pulse;

the isolation conversion module 3 is electrically connected with the signal conversion module 2 and is used for amplifying the control pulse output by the signal conversion module 2 by multiple times, rectifying, filtering and stabilizing voltage and outputting stable MOS driving control voltage;

the drive protection module 4 is electrically connected with the isolation conversion module 3 and is used for conducting and stopping control on the MOS tube pair tubes 5 and realizing protection on abnormal current conditions by monitoring the MOS tube pair tube current in real time;

and the MOS tube pair transistor 5 is formed by connecting two MOS tubes in series and is electrically connected with the drive protection module 4, so that the bidirectional contactless control of a control loop is realized.

The code conversion module 1 is an SN74AHC1G08 one-way AND gate chip. The signal conversion module 2 is an SN6505 push-pull transformer driver, and a pin number four of the SN74AHC1G08 one-way AND gate chip is connected with a pin number five of the SN6505 push-pull transformer driver. The signal conversion module 2 is an SN6505 push-pull transformer driver, and a pin number four of the SN74AHC1G08 one-way AND gate chip is connected with a pin number five of the SN6505 push-pull transformer driver. The isolation conversion module 3 is formed by connecting a pulse transformer, a rectifier bridge and a voltage stabilizing and filtering unit in series, and a first pin, a second pin and a third pin of an SN6505 push-pull transformer driver are connected to the input side of the pulse transformer. The voltage stabilizing and filtering unit comprises a first capacitor C1, a first resistor R1 and a first voltage stabilizing diode D1 which are connected in parallel with the output end of the rectifier bridge, and the output end of the rectifier bridge is also connected with a second resistor R2 and a second voltage stabilizing diode D2 in series. The driving protection module 4 comprises a first MOS transistor driving chip IR2127S and a second MOS transistor driving chip IR2127S which are arranged in parallel, wherein a first pin, a second pin and a fourth pin of the two MOS transistor driving chips IR2127S are respectively connected to the anode of the rectifier bridge, between the second resistor R2 and the second zener diode D2 and the cathode of the rectifier bridge. A fifth pin of the first MOS transistor driver chip IR2127S is connected to a source electrode of the first MOS transistor, a fourth resistor R4 is connected between the fifth pin and a sixth pin of the first MOS transistor driver chip IR2127S, the sixth pin of the first MOS transistor driver chip IR2127S is connected to a drain electrode of the first MOS transistor through a third resistor R3 and a third ultrafast recovery diode D3 which are connected in series, and a seventh pin of the first MOS transistor driver chip IR2127S is connected to a gate electrode of the first MOS transistor through a fifth resistor R5; the fifth pin of the second MOS transistor driver chip IR2127S is connected to the source of the second MOS transistor, a seventh resistor R7 is connected between the fifth pin and the sixth pin of the second MOS transistor driver chip IR2127S, the sixth pin of the second MOS transistor driver chip IR2127S is connected to the drain of the second MOS transistor through a sixth resistor R6 and a fourth ultrafast recovery diode D4 which are connected in series, and the seventh pin of the second MOS transistor driver chip IR2127S is connected to the gate of the second MOS transistor through an eighth resistor R8. The source electrodes of the first MOS tube and the second MOS tube in the MOS tube pair 5 are connected.

The utility model discloses a theory of operation does: the TTL level combination signals a1 and a2 are subjected to logic analysis and rule determination by a code conversion module (as shown in fig. 5, IC1 is a single and gate chip of TI corporation, model number is SN74AHC1G08, and here, may also be designed as any logic circuit of an agreed rule), and convert the input signal conforming to the conversion rule into a single TTL output control signal, and transmit the single TTL output control signal to the signal conversion unit. The signal conversion circuit IC2(IC2 is TI corporation push-pull transformer driver SN6505) converts the effective output control signal into a drive pulse; the driving pulse is isolated and amplified by a pulse transformer L1 of the isolation conversion module, is subjected to full-wave rectification by a bridge stack Z1, and is filtered and stabilized into direct-current supply voltage required by a driving protection circuit by a 10uF/50V capacitor C1, a 100K resistor R1 and an 18V voltage-stabilizing tube D1. A voltage-dividing voltage stabilizing circuit consisting of a 7.5V voltage regulator tube D2 and a 20K resistor R2 generates MOS tube drive trigger level (drive enable). After the MOS tube driving chips IC3 and IC4 (may use IR2127S from international rectifier corporation) are powered on, the driving output enable signal is valid, and then the output high level of the 7 th pin of IC3 and IC4 drives the MOS tubes Q1 and Q2 (i.e. MOS tube type number IXFA22N65X2 from eisis corporation or MOS tube type number IPB60R120C7 from english-flying corporation) to be turned on through R5(1K) and R8 (1K); an over-current monitoring loop consisting of an ultrafast recovery diode D3, a 20K resistor R3 and a 30K resistor R4 feeds back the conduction junction voltage of the first MOS transistor Q1 to the 6 th pin of the IC3 through voltage division adjustment; an over-current monitoring loop composed of an ultrafast recovery diode D4, a 20K resistor R6 and a 30K resistor R7 feeds back the voltage of a conducting junction of a second MOS tube Q2 to a 6 th pin of the IC4 through voltage division adjustment, and once an over-current threshold value is reached, a corresponding driving signal is blocked: if the current direction is from A to B, the overcurrent protection of the first MOS tube Q1 is turned off, and if the current direction is from B to A, the overcurrent protection of the second MOS tube Q2 is turned off, so that bidirectional protection is implemented on a conducting loop between A, B nodes.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the spirit of the present disclosure, features from the above embodiments or from different embodiments may also be combined, steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments in this application as described above, which are not provided in detail for the sake of brevity. It is intended that the one or more embodiments of the present application embrace all such alternatives, modifications and variations as fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements, and the like that may be made without departing from the spirit and principles of one or more embodiments of the present disclosure are intended to be included within the scope of the present disclosure.

Claims (8)

1. The utility model provides a can two-way protection dry contact control circuit which characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

the code conversion module (1) is used for receiving TTL input signals with a code rule sent by a processor or a controller, and converting the TTL input signals which accord with the conversion rule into single TTL output control signals through logic analysis and rule judgment;

the signal conversion module (2) is electrically connected with the code conversion module (1) and is used for converting the single TTL output control signal output by the code conversion module (1) into a control pulse;

the isolation conversion module (3) is electrically connected with the signal conversion module (2) and is used for amplifying the control pulse output by the signal conversion module (2) by multiple times, rectifying, filtering and stabilizing voltage and outputting stable MOS drive control voltage;

the drive protection module (4) is electrically connected with the isolation conversion module (3) and is used for conducting and stopping control on the MOS tube geminate transistors (5) and realizing protection on abnormal current conditions by monitoring the MOS tube geminate transistors current in real time;

and the MOS tube pair tube (5) is formed by connecting a first MOS tube and a second MOS tube in series and is electrically connected with the drive protection module (4) to realize bidirectional contactless control of the control loop.

2. The bidirectionally protected dry contact control circuit of claim 1, wherein: the code conversion module (1) is an SN74AHC1G08 one-way AND gate chip.

3. The bidirectionally protected dry contact control circuit of claim 2, wherein: the signal conversion module (2) is an SN6505 push-pull transformer driver, and a pin IV of an SN74AHC1G08 one-way AND gate chip is connected with a pin V of the SN6505 push-pull transformer driver.

4. A bidirectionally protected dry contact control circuit as claimed in claim 3, wherein: the isolation conversion module (3) is formed by connecting a pulse transformer, a rectifier bridge and a voltage stabilizing and filtering unit in series, and a first pin, a second pin and a third pin of an SN6505 push-pull transformer driver are connected to the input side of the pulse transformer.

5. The bidirectionally protected dry contact control circuit of claim 4, wherein: the voltage stabilizing and filtering unit comprises a first capacitor (C1), a first resistor (R1) and a first voltage stabilizing diode (D1) which are connected in parallel at the output end of the rectifier bridge, and the output end of the rectifier bridge is also connected with a second resistor (R2) and a second voltage stabilizing diode (D2) in series.

6. The bidirectionally protected dry contact control circuit of claim 5, wherein: the driving protection module (4) comprises a first MOS tube driving chip IR2127S and a second MOS tube driving chip IR2127S which are arranged in parallel, and a first pin, a second pin and a fourth pin of the two MOS tube driving chips IR2127S are respectively connected to the anode of the rectifier bridge, between the second resistor (R2) and the second voltage stabilizing diode (D2) and the cathode of the rectifier bridge.

7. The bidirectionally protected dry contact control circuit of claim 6, wherein: a fifth pin of the first MOS tube driving chip IR2127S is connected to a source electrode of the first MOS tube, a fourth resistor (R4) is connected between the fifth pin and a sixth pin of the first MOS tube driving chip IR2127S, the sixth pin of the first MOS tube driving chip IR2127S is connected to a drain electrode of the first MOS tube through a third resistor (R3) and a third ultrafast recovery diode (D3) which are connected in series, and a seventh pin of the first MOS tube driving chip IR2127S is connected to a gate electrode of the first MOS tube through the fifth resistor (R5); the fifth pin of the second MOS transistor driving chip IR2127S is connected to the source of the second MOS transistor, a seventh resistor (R7) is connected between the fifth pin and the sixth pin of the second MOS transistor driving chip IR2127S, the sixth pin of the second MOS transistor driving chip IR2127S is connected to the drain of the second MOS transistor through the sixth resistor (R6) and the fourth ultrafast recovery diode (D4) which are connected in series, and the seventh pin of the second MOS transistor driving chip IR212 2127S is connected to the gate of the second MOS transistor through the eighth resistor (R8).

8. The bidirectionally protected dry contact control circuit of claim 1, wherein: and the source electrodes of the first MOS tube and the second MOS tube in the MOS tube pair tube (5) are connected.

Images