CN201233842Y

CN201233842Y - Electric relay driving circuit

Info

Publication number: CN201233842Y
Application number: CNU2008200932449U
Authority: CN
Inventors: 汪显方; 杨勇练; 邓宝宁; 刘建伟; 董晓勇; 蒋洪波
Original assignee: Shenzhen H&T Intelligent Control Co Ltd
Current assignee: Shenzhen H&T Intelligent Control Co Ltd
Priority date: 2008-04-03
Filing date: 2008-04-03
Publication date: 2009-05-06
Anticipated expiration: 2018-04-03

Abstract

The utility model relates to a relay drive circuit, which comprises a power circuit (1), a relay (2), loads (3), and a control circuit (4) used for controlling the relay (2); and the power circuit (1) is used for providing the working current of the relay (2) and the loads (3). The relay drive circuit is characterized in that the relay (2) is connected in series with the loads (3), and further comprises MCU connected with the control circuit (4) and provided with a control port used for controlling the control circuit (4). Aiming at the defects of over-high capacity of a depression capacitor and easy misoperation on the relay, the utility model changes two groups of loads into a current serial structure, so as to reduce the capacity of the depression capacitor, thereby reducing the space and the cost. In addition, the relay adopts a pulsed drive manner, thereby preventing the misoperation on the relay.

Description

A kind of relay drive circuit

Technical field

The utility model relates to relay control, more particularly, relates to a kind of relay drive circuit.

Background technology

The resistance-capacitance depressurization power circuit is applicable to that there is the situation of controllable silicon and relay in load, owing to have controllable silicon in the circuit, so general employing is half-wave rectifying circuit, purpose is directly to trigger controllable silicon, saves cost.

As depicted in figs. 1 and 2, for the power circuit among the figure 1, two groups of loads are arranged in the circuit: relay 2 and load 3 (being Vcc).The connection commonly used of these two kinds of loads as shown in Figure 1, we are referred to as current parallel formula structure.Suppose that the electric current that first group of load (being relay R Y1) needs is I1, the electric current that second group of load (being Vcc) needs is I2, we are when the capacity of the decompression capacitor C1 that selects power circuit 1 so, will consider that electric current I 0 that it can provide is greater than equals total load current, promptly satisfies I0 〉=I1+I2.

This parallel structure makes that the capacity of the decompression capacitor C1 in the power circuit 1 can be very big, and the control mode of relay R Y1 is not the mode of pulsed drive, is easy to generate misoperation.

The utility model content

The technical problems to be solved in the utility model is, excessive and relay is easy to generate the defective of misoperation at the capacity of decompression capacitor, provides a kind of and reduces decompression capacitor and prevent that relay from producing the relay drive circuit of misoperation.

The technical scheme that its technical problem that solves the utility model adopts is: construct a kind of relay drive circuit, comprise power circuit, relay, load and be used to control the control circuit of described relay, power circuit is used to provide the electric current of relay and loaded work piece, described relay is connected with load, and described relay drive circuit comprises that also being provided with of being connected with described control circuit is used for the MCU of control port I/O that control circuit is controlled.

In relay drive circuit described in the utility model, the electric current that power circuit provides is I0, and the electric current by relay and load is respectively I1, I2, wherein I0 〉=I1〉I2.

In relay drive circuit described in the utility model, described power circuit is a resistance-capacitance depressurization halfwave rectifier power circuit, comprises dropping resistor R1 and capacitor C 1.

In relay drive circuit described in the utility model, described control port I/O provides pulse drive signal that control circuit is controlled.

In relay drive circuit described in the utility model, described control circuit comprises triode TR1, TR2, control port I/O control triode TR2, and triode TR2 and then control triode TR1 so control the folding of relay.

In relay drive circuit described in the utility model, described control circuit also comprises the pull-up resistor R2 that is connected between zero line L and the triode TR2 base stage, is used for making when control port I/O does not have control signal triode TR2 to be in cut-off state.

Implement relay drive circuit of the present utility model, have following beneficial effect: make two groups of loads into the electric current cascaded structure, can reduce the capacity of decompression capacitor, thereby reduce the space and reduce cost; Relay adopts the mode of pulsed drive, can prevent the relay misoperation work.

Description of drawings

The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:

Fig. 1 is the system block diagram of the relay drive circuit of prior art;

Fig. 2 is the schematic diagram of the relay drive circuit of prior art;

Fig. 3 is the system block diagram of the utility model relay drive circuit;

Fig. 4 is the schematic diagram of the utility model relay drive circuit;

Fig. 5 is the local schematic diagram of the utility model relay drive circuit;

The schematic diagram of current direction when Fig. 6 A is power-half period relay adhesive;

Fig. 6 B is the schematic diagram of current direction when the power-half period, relay was opened;

The schematic diagram of current direction when Fig. 6 C is the positive half cycle of power supply.

Embodiment

As shown in Figure 3, relay drive circuit of the present utility model comprises power circuit 1, relay 2, load 3 and is used to control the control circuit 4 of described relay 2, power circuit 1 is used to provide the electric current of relay 2 and load 3 work, relay 2 is connected with load 3, control circuit 4 is also connected to the control port I/O of MCU, is used for control circuit 4 is controlled.Compared to existing technology, two groups of loads make the electric current cascaded structure into, can reduce the capacity of decompression capacitor, thereby reduce the space and reduce cost.The electric current that power circuit 1 provides is I0, and the electric current by relay 2 and load 3 is respectively I1, I2, wherein I0 〉=I1〉I2.Control port I/O provides pulse drive signal that control circuit 4 is controlled, and can prevent relay 2 misoperations like this.

As shown in Figure 4, power circuit 1 is a resistance-capacitance depressurization halfwave rectifier power circuit, comprises dropping resistor R1 and capacitor C 1.Control circuit 4 comprises triode TR1, TR2, control port I/O control triode TR2, and triode TR2 and then control triode TR1 so control the folding of relay 2.Control circuit 4 also comprises the pull-up resistor R2 that is connected between zero line L and the triode TR2 base stage, is used for making when control port I/O does not have control signal triode TR2 to be in cut-off state.In this circuit, the power supply of relay R Y1 and Vcc are the relations of polyphone.Suppose that the electric current that relay R Y1 needs is I1, the electric current that the Vcc rear end needs is I2, if I2〉I1, total load current is I2.The electric current that decompression capacitor can provide is I0, and we have just satisfied as long as consider I0 〉=I2 in the capacity of selecting decompression capacitor C1 so, rather than I0 〉=I2+I1, has so just reduced the volume and the cost of decompression capacitor, has also reduced circuit power consumption simultaneously.

Fig. 5 is the local schematic diagram of the utility model relay drive circuit, the schematic diagram of current direction when Fig. 6 A is power-half period relay adhesive, Fig. 6 B is the schematic diagram of current direction when the power-half period, relay did not have adhesive, the schematic diagram of current direction when Fig. 6 C is the positive half cycle of power supply.When relay R Y1 needs adhesive, triode TR1 conducting, electric current can flow through the coil (as Fig. 6 A) of relay R Y1; When relay R Y1 did not need adhesive, triode TR1 ended, and did not have electric current to flow through in the coil of relay R Y1, and electric current forms loop (as Fig. 6 B) through the ZD1 voltage stabilizing didoe.

Between the negative half-cycle of power supply, when needing to open relay R Y1, control port I/O mouth has pulse signal output, is coupled to the base stage of triode TR2 through C14, R17.Triode TR2 conducting between the negative half-cycle of pulse, electric current is from the emitter of the TR2 collector electrode of flowing through, charge to capacitor C 2 through resistance R 20, power to the TR1 base stage through R12 simultaneously, make triode TR1 conducting, the coil of relay R Y1 has electric current to flow through, and the relay adhesive is charged to C11 simultaneously.When the positive half cycle of pulse, capacitor C 14 is by the D1 diode discharge, and triode TR2 ends.Capacitor C 2 to the power supply of TR1 transistor base, is kept TR1 conducting, relay adhesive by resistance R 12.Resistance R 2 is pull-up resistors, guarantees when not having control signal, and the base stage of triode TR2 is in high level state, i.e. the triode cut-off state.

At the positive half cycle of power supply, electric current is shown in Fig. 6 C, and source current directly flows to the other end through the D2 diode, the load of the back of not flowing through.C11 keeps the relay adhesive by relay R Y1, triode TR1 discharge.When not needing attracting electric relay, the control port I/O of MCU does not have pulse signal output, and triode TR2, TR1 end.MCU will send signal and make the relay adhesive in the time of normal the use, and signal just disappears when MCU breaks down, and relay just automatically springs open.

The utility model makes two groups of loads into the electric current cascaded structure, can reduce the capacity of decompression capacitor, thereby reduces the space and reduce cost; Relay adopts the mode of pulsed drive, can prevent the relay misoperation work.

Claims

1, a kind of relay drive circuit, comprise power circuit (1), relay (2), load (3) and be used to control the control circuit (4) of described relay (2), power circuit (1) is used to provide the electric current of relay (2) and load (3) work, it is characterized in that, described relay (2) is connected with load (3), and described relay drive circuit comprises that also being provided with of being connected with described control circuit (4) is used for the MCU of control port I/O that control circuit (4) is controlled.

2, relay drive circuit according to claim 1 is characterized in that, the electric current that power circuit (1) provides is IO, and the electric current by relay (2) and load (3) is respectively I1, I2, wherein IO 〉=I1〉I2.

3, relay drive circuit according to claim 1 is characterized in that, described power circuit (1) is a resistance-capacitance depressurization halfwave rectifier power circuit, comprises dropping resistor R1 and capacitor C 1.

4, relay drive circuit according to claim 1 is characterized in that, described control port I/O provides pulse drive signal that control circuit (4) is controlled.

5, relay drive circuit according to claim 4, it is characterized in that described control circuit (4) comprises triode TR1, TR2, control port I/O control triode TR2, triode TR2 and then control triode TR1 so control the folding of relay (2).

6, relay drive circuit according to claim 5, it is characterized in that, described control circuit (4) also comprises the pull-up resistor R2 that is connected between zero line L and the triode TR2 base stage, is used for making when control port I/O does not have control signal triode TR2 to be in cut-off state.