CN105206475A - A switch-controlled magnetic latching relay drive circuit - Google Patents

Abstract

A magnetic latching relay drive circuit controlled by a switch aims to solve the problem that when a magnetic latching relay is controlled, forward and reverse pulses need to be provided, so that the use is inconvenient. The driving circuit comprises two capacitors, two relays, a power supply and a switch. One relay has three groups of contacts which are normally closed and one group of contacts which are normally open, and the other relay has two groups of contacts which are normally closed and one group of contacts which are normally open. The power supply and the switch are connected in series and then connected in parallel with the coils of the two relays, and the coils of the magnetic latching relays are connected with the two capacitors through the normally open contacts and the normally closed contacts of the two relays. The on-off of the two relay coils is controlled through the switch, and then the charging and discharging of the capacitor are controlled, so that positive pulses and negative pulses are provided for the coils of the magnetic latching relay, and the magnetic latching relay and the general relay have the same driving mode. The invention can realize the on-off control of the magnetic latching relay by using the switch, has convenient use and quick action and is particularly suitable for the load switch of the intelligent electric energy meter.

Description

A switch-controlled magnetic latching relay drive circuit

technical field

The invention relates to the driving technology of a magnetic latching relay.

Background technique

The magnetic latching relay is a new type of relay developed in recent years, and it is also an automatic switch. Like other electromagnetic relays, it can automatically switch on and off the circuit. The difference is that the normally closed or normally open state of the magnetic latching relay is completely dependent on the effect of the permanent magnet, and the switching state of the relay is triggered by a pulse electric signal of a certain width.

The contact state of the magnetic latching relay is maintained by the magnetic force of the permanent magnet steel. When the control contact is switched, input a certain width of positive DC pulse at both ends of the coil to realize the connection of the magnetic latching relay. Input a certain width at both ends of the coil. The reverse DC pulse can realize the cut-off of the magnetic latching relay. Therefore, when controlling the magnetic latching relay, it is necessary to provide forward and reverse pulses, which brings a lot of inconvenience to users.

Contents of the invention

The purpose of the present invention is to solve the problem of inconvenient use due to the need to provide forward and reverse pulses when controlling a magnetic latching relay, and to provide a magnetic latching relay drive circuit controlled by a switch.

A switch-controlled magnetic latching relay driving circuit according to the present invention includes a No. 1 relay A, a No. 2 relay B, a No. 1 capacitor C1, a No. 2 capacitor C2, a power supply V and a switch K;

The No. 1 relay A has four sets of contacts, that is, A No. 1 contact A1 to A No. 4 contact A4, among which A No. 1 contact A1 to A No. 3 contact A3 are normally closed contacts, and A No. 4 contact Point A4 is a normally open contact;

No. 2 relay B has three sets of contacts, that is, B No. 1 contact B1 to B No. 3 contact B3, among which B No. 1 contact B1 is a normally open contact, B No. 2 contact B2 and B No. 3 contact B3 are normally closed contacts;

The pull-in time of No. 1 relay A is greater than the pull-in time of No. 2 relay B, and the release time of No. 1 relay A is longer than the release time of No. 2 relay B;

The power supply V is connected in series with the switch K to form a series branch, and the series branch is connected in parallel with the coil AC of the No. 1 relay A and the coil BC of the No. 2 relay B to form a parallel branch;

One end of the No. 1 capacitor C1 is simultaneously connected to one end of A No. 1 contact A1 and one end of A No. 4 contact A4;

One end of the second capacitor C2 is connected to one end of the second contact B2 of B and one end of the second contact A2 of A;

The other end of the No. 2 capacitor C2 is simultaneously connected to one end of the A No. 3 contact A3 and one end of the B No. 3 contact B3;

The other end of A No. 2 contact A2 is simultaneously connected with one end of the parallel branch and the other end of A No. 1 contact A1;

The other end of A No. 3 contact A3 is simultaneously connected to the other end of the parallel branch, the other end of No. 1 capacitor C1 and one end of B No. 1 contact B1;

The other end of B No. 1 contact B1 and the other end of B No. 2 contact B2 are simultaneously connected to one end of the coil MC of the magnetic latching relay;

The other end of the third contact B3 of B and the other end of the fourth contact A4 of A are simultaneously connected to the other end of the coil MC of the magnetic latching relay.

The drive circuit of the present invention includes two capacitors, a relay with four sets of contacts (three sets of normally closed, one set of normally open), a relay with three sets of contacts (two sets of normally closed, one set of normally open ), a power supply and a switch, wherein the power supply and the switch are connected in series and connected in parallel with two relay coils, and the coil of the magnetic latching relay is connected to two capacitors through the normally open and normally closed contacts of the two relays. The above drive circuit can realize the on-off control of the magnetic latching relay by using the switch, that is, the magnetic latching relay is turned on when the switch is closed, and the magnetic latching relay is turned off when the switch is turned off. It has the advantages of convenient use and fast action, and is especially suitable for smart energy meters load switch.

Description of drawings

FIG. 1 is a schematic structural diagram of a switch-controlled magnetic latching relay drive circuit according to the first embodiment.

Detailed ways

Specific Embodiment 1: This embodiment is described in conjunction with FIG. 1. A switch-controlled magnetic latching relay drive circuit described in this embodiment includes No. 1 relay A, No. 2 relay B, No. 1 capacitor C1, No. 2 capacitor C2, Power supply V and switch K;

The No. 1 relay A has four sets of contacts, that is, A No. 1 contact A1 to A No. 4 contact A4, among which A No. 1 contact A1 to A No. 3 contact A3 are normally closed contacts, and A No. 4 contact Point A4 is a normally open contact; No. 2 relay B has three sets of contacts, that is, B No. 1 contact B1 to B No. 3 contact B3, among which B No. Point B2 and B No. 3 contact B3 are normally closed contacts; the pull-in time of No. 1 relay A is greater than the pull-in time of No. 2 relay B, and the release time of No. 1 relay A is longer than the release time of No. 2 relay B;

The power supply V is connected in series with the switch K to form a series branch, and the series branch is connected in parallel with the coil AC of the No. 1 relay A and the coil BC of the No. 2 relay B to form a parallel branch;

One end of the No. 1 capacitor C1 is simultaneously connected to one end of A No. 1 contact A1 and one end of A No. 4 contact A4;

One end of the second capacitor C2 is connected to one end of the second contact B2 of B and one end of the second contact A2 of A;

The other end of the No. 2 capacitor C2 is simultaneously connected to one end of the A No. 3 contact A3 and one end of the B No. 3 contact B3;

The other end of A No. 2 contact A2 is simultaneously connected with one end of the parallel branch and the other end of A No. 1 contact A1;

The other end of A No. 3 contact A3 is simultaneously connected to the other end of the parallel branch, the other end of No. 1 capacitor C1 and one end of B No. 1 contact B1;

The other end of B1 contact B1 and the other end of B2 contact B2 are simultaneously connected to one end of the coil MC of the magnetic latching relay; the other end of B3 contact B3 is connected to the other end of A4 contact A4 at the same time Connect the other end of the coil MC of the magnetic latching relay.

After the switch K is closed, the coil AC of the No. 1 relay A and the coil BC of the No. 2 relay B are energized. Since the time required for charging the capacitor is very short, before the No. 1 contact A1 to the No. 3 contact A3 of A are disconnected, a Capacitor C1 and capacitor C2 are both charged to the power supply voltage; since the pull-in time of relay A of the first is greater than the pull-in time of relay B of the second, the normally closed contact of the second relay B is the second contact B2 of B And B No. 3 contact B3 is closed, then the normally open contact of No. 1 relay A is A No. 1 contact A1 to A No. 3 contact A3 is disconnected, and A No. 4 contact A4 is closed. On the one hand, the No. 2 capacitor C2 is disconnected from the circuit, and on the other hand, the No. 1 capacitor C1 discharges to the coil M of the magnetic latching relay through A No. 4 contact A4 and B No. 1 contact B1, which is equivalent to providing a positive pulse for the magnetic latching relay, and the magnetic latching relay connected.

After the switch K is disconnected, the coil AC of the No. 1 relay A and the coil BC of the No. 2 relay B lose power. Since the release time of the No. 1 relay A is longer than the release time of the No. 2 relay B, the normally open contact of the No. 2 relay B That is, B1 contact B1 is disconnected first, and the normally closed contact is B2 contact B2 and B3 contact B3 are closed, and the second capacitor C2 passes through B2 contact B2 and B3 contact B3 to The magnetic latching relay is discharged. Since the discharge direction is opposite to that of the No. 1 capacitor C1, it is equivalent to providing a negative pulse for the magnetic latching relay, and the magnetic latching relay is disconnected; then the normally open contact of the No. 1 relay A is A4. Open, the normally closed contacts are A No. 1 contact A1 to A No. 3 contact A3 are closed, ready for the charging of No. 1 capacitor C1 when the switch K is closed next time.

Therefore, the drive circuit described in this embodiment can use the switch K to control the on-off of the magnetic latching relay, that is, the magnetic latching relay has the same driving method as the general-purpose relay, which is convenient for users to use.

Specific Embodiment 2: This embodiment is described in conjunction with FIG. 1. This embodiment is a further limitation of a switch-controlled magnetic latching relay drive circuit described in Embodiment 1. In this embodiment, the first capacitor C1 and the second capacitor The capacitance values of C2 are all greater than 200μF.

The ampere-turn is the unit of the magnetomotive force, which is equal to the product of the number of turns of the coil and the current passing through the coil. The larger the number of ampere-turns, the stronger the magnetic field generated. When the capacitance values of the No. 1 capacitor C1 and the No. 2 capacitor C2 are both greater than 200μF, the reverse discharge current value to the coil MC connected to the magnetic latching relay is larger, and the number of turns of the coil MC connected to the magnetic latching relay is constant, so the safety The larger the number of turns, the stronger the magnetic field produced. The on-off action of the magnetic latching relay requires an appropriate number of ampere-turns. When the capacitance of the two capacitors is greater than 200 microfarads, the magnetic latching relay obtains a suitable number of ampere-turns, and can ensure that the charging and discharging time of the capacitor meets the requirements of the relay pull-in. The time needed, the control effect is better.

Claims (2)

1. a magnetic latching relay drive circuit of switch control, is characterized in that, it comprises No. 1 relay (A), No. 2 relay (B), No. 1 capacitor (C1), No. 2 capacitor (C2), power supply (V ) and switch (K); The No. 1 relay (A) has four sets of contacts, that is, A No. 1 contact (A1) to A No. 4 contact (A4), among which A No. 1 contact (A1) to A No. 3 contact (A3) are all It is a normally closed contact, and A No. 4 contact (A4) is a normally open contact; The No. 2 relay (B) has three sets of contacts, namely B No. 1 contact (B1) to B No. 3 contact (B3), among which B No. 1 contact (B1) is a normally open contact, and B No. Point (B2) and B No. 3 contact (B3) are both normally closed contacts; The pull-in time of the No. 1 relay (A) is longer than the pull-in time of the No. 2 relay (B), and the release time of the No. 1 relay (A) is longer than the release time of the No. 2 relay (B); The power supply (V) is connected in series with the switch (K) to form a series branch, which is connected in parallel with the coil (AC) of the No. 1 relay (A) and the coil (BC) of the No. 2 relay (B) to form a parallel branch ; One end of the No. 1 capacitor (C1) is simultaneously connected to one end of the A No. 1 contact (A1) and one end of the A No. 4 contact (A4); One end of the No. 2 capacitor (C2) is simultaneously connected to one end of the No. B contact point (B2) and one end of the No. A contact point (A2); The other end of the No. 2 capacitor (C2) is simultaneously connected to one end of the A No. 3 contact (A3) and one end of the B No. 3 contact (B3); The other end of A No. 2 contact (A2) connects one end of described parallel branch and an other end of A No. 1 contact (A1) simultaneously; The other end of the A No. 3 contact (A3) is connected to the other end of the parallel branch, the other end of the No. 1 capacitor (C1) and one end of the No. B No. 1 contact (B1) simultaneously; The other end of B No. 1 contact (B1) and the other end of B No. 2 contact (B2) are simultaneously connected to one end of the coil (MC) of the magnetic latching relay; The other end of the B No. 3 contact (B3) and the other end of the A No. 4 contact (A4) are simultaneously connected to the other end of the coil (MC) of the magnetic latching relay. 2. A switch-controlled magnetic latching relay drive circuit according to claim 1, characterized in that the capacitance values of the No. 1 capacitor (C1) and the No. 2 capacitor (C2) are both greater than 200 μF.