CN208507582U - A kind of relay and its degausser - Google Patents

Abstract

The utility model discloses a relay and a demagnetization circuit thereof, wherein the demagnetization circuit comprises a demagnetization branch, a discharge load and a switch device. The demagnetization branch is connected in parallel with both ends of the coil of the relay, which can absorb the residual magnetic energy of the coil during the demagnetization process. When demagnetization is required, the power supply circuit where the coil is located is disconnected by turning off the switching device, and the residual magnetism at both ends of the coil is absorbed by the demagnetization branch. Since the energy storage element capacitor is added to the demagnetization circuit, the capacitor can store residual magnetic energy. At this time, the demagnetization voltage is the sum of the voltage across the capacitor and the forward voltage of the reverse diode. Therefore, compared with only the As far as the forward voltage of the reverse diode is concerned, it can quickly demagnetize, thereby reliably eliminating the relay bounce phenomenon. In addition, the circuit structure is simple, the cost is low, and the application scenarios are wide.

Description

A relay and its demagnetization circuit

technical field

The utility model relates to the technical field of relays, in particular to a relay and a demagnetization circuit thereof.

Background technique

The relay mentioned in the present invention is a mechanical structure relay (with a push rod), and it is an inherent property of the relay to generate bounce during the action and opening process. The reason why the rebound occurs is because of the following reasons: In essence, the shrapnel of the relay is a kind of leaf spring, and the material with strong elasticity is usually selected to ensure that the movable shrapnel has a certain restoring force, so that the dynamic and static contact after the coil is powered off. The point can be broken quickly. When the coil is energized, the shrapnel is driven by the push rod to move rapidly. When the movable contact reaches the static contact, a violent collision occurs, and the speed drops to zero in a very short time, resulting in a great reverse effect. The force and the reaction force make the shrapnel move in the opposite direction, so that the movable contact and the static contact are separated again, resulting in a rebound. At this time, due to the existence of continuous current, the coil will still maintain "residual magnetism" after the power is turned off. This residual magnetism is the same as when the coil is energized, so that the suction force generated by the coil always exists. Much larger than the restoring force of the shrapnel, it will stop after many times, and the rebound phenomenon will stop.

In some circuits, this bounce phenomenon will cause arcing or even bonding of the moving and static contacts of the relay, resulting in serious consequences for the relay and the circuit where it is located.

In the prior art, in order to overcome this shortcoming, a reverse diode is usually connected in parallel at both ends of the coil or a reverse diode and a Zener diode are connected in parallel at both ends of the coil (the reverse diode and the Zener diode are in series structure). FIG. 1 is a demagnetization circuit of a relay provided in the prior art. As shown in Figure 1, a reverse diode D1 is connected in parallel at both ends of the coil RLY, and a triode Q1 is added between the coil RLY and the ground. By inputting a control signal to the base of the triode Q1, the on and off of the triode are controlled. open. When the transistor Q1 is turned off, the reverse electromotive force generated at both ends of the coil RLY is clamped at the forward conduction voltage of the reverse diode D1, thereby suppressing the problem of bounce. However, when the reverse diode D1 is used as the demagnetization circuit, the demagnetization voltage is the forward voltage of the reverse diode D1, the demagnetization voltage is low, and the demagnetization is slow.

It can be seen from this that how to speed up the demagnetization speed of the coil so as to overcome the problem of relay bounce is an urgent problem to be solved by those skilled in the art.

Utility model content

The purpose of the utility model is to provide a demagnetization circuit for a relay, which is used to speed up the demagnetization speed of the coil, thereby overcoming the problem of the relay bounce. In addition, the present invention also provides a relay including the demagnetization circuit.

In order to solve the above technical problems, the present utility model provides a demagnetization circuit of a relay, which includes a demagnetization branch connected in parallel with both ends of the coil of the relay, a discharge load and a switching device, and the demagnetization branch includes a capacitor connected in series and a switching device. a reverse diode, the discharge load is connected in parallel with both ends of the capacitor, and is used to absorb the electric energy released by the capacitor; Disconnect the power supply circuit.

Preferably, the bleeder load is specifically a bleeder resistor.

Preferably, the switching device is specifically a triode.

Preferably, the triode is an NPN triode, the base of the NPN triode serves as the input end of the switching signal, and the collector of the NPN triode is composed of the coil and the anode of the reverse diode The common terminal is connected, and the emitter of the NPN transistor is grounded.

Preferably, a current limiting resistor is also included, and the current limiting resistor is disposed at the front end of the base of the NPN triode to serve as the input end of the switch signal.

Preferably, a voltage dividing resistor is also included, one end of the voltage dividing resistor is connected to the base of the NPN triode, and the other end of the voltage dividing resistor is connected to the emitter of the NPN triode.

In order to solve the above technical problems, the present invention also provides a relay, which includes a relay body and the above-mentioned demagnetization circuit.

The demagnetization circuit provided by the utility model includes a demagnetization branch, a discharge load and a switch device, wherein the demagnetization branch is connected in parallel with both ends of the coil of the relay, and can absorb the residual magnetic energy of the coil during the demagnetization process. When demagnetization is required, the power supply circuit where the coil is located is disconnected by turning off the switching device, and the residual magnetism at both ends of the coil is absorbed by the demagnetization branch. Since the energy storage element capacitor is added to the demagnetization circuit, the capacitor can store residual magnetic energy. At this time, the demagnetization voltage is the sum of the voltage across the capacitor and the forward voltage of the reverse diode. Therefore, compared with only the As far as the forward voltage of the reverse diode is concerned, it can quickly demagnetize, thereby reliably eliminating the relay bounce phenomenon. In addition, the circuit structure is simple, the cost is low, and the application scenarios are wide. Finally, the relay provided by the present invention also has the above beneficial effects.

Description of drawings

In order to explain the embodiments of the present invention more clearly, the following will briefly introduce the accompanying drawings used in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, which are very important in the art. For those of ordinary skill, other drawings can also be obtained from these drawings without any creative effort.

1 is a demagnetization circuit of a relay provided by the prior art;

2 is a circuit diagram of a demagnetization circuit of a relay provided by an embodiment of the present invention;

FIG. 3 is a circuit diagram of another demagnetization circuit of a relay provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. . Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The core of the utility model is to provide a demagnetization circuit of the relay, which is used to speed up the demagnetization speed of the coil, so as to overcome the problem of the relay bounce. In addition, the present invention also provides a relay including the demagnetization circuit.

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 2 is a circuit diagram of a demagnetization circuit of a relay provided by an embodiment of the present invention. As shown in Figure 2, the demagnetization circuit includes a demagnetization branch connected in parallel with both ends of the coil RLY of the relay, a bleeder load (implemented by a bleeder resistor R1 in Figure 2) and a switching device (implemented by a transistor Q1 in Figure 2) , the demagnetization branch includes a capacitor C1 and a reverse diode D1 connected in series, the discharge load is connected in parallel with both ends of the capacitor C1, and is used to absorb the electric energy released by the capacitor C1. Turn on or off the power supply circuit according to the switch signal.

It should be noted that the bleeder load in this embodiment refers to all devices capable of absorbing the electrical energy of the coil RLY, for example, it may be a resistor, which is also called a bleeder resistor R1 in order to distinguish it from other resistors. It is understandable that, as a bleeder load, the resistance is not only low cost, but also has a fast response speed. It can be understood that, in addition to resistors, other types of devices can also be used as bleeder loads, and details are not described in this embodiment.

As shown in Figure 2, the two ends of the coil RLY are defined as the first end and the second end, respectively, the first end is connected to the positive +VCC of the power supply, and the second end is grounded through the switching device. When the switching device is turned on, the coil RLY The power supply loop is turned on, and when the switching device is turned off, the power supply loop of the coil RLY is disconnected. When the power supply circuit of the coil RLY is turned on, the coil RLY is energized. At this time, if the power supply circuit is disconnected, the back electromotive force at both ends of the coil RLY will be released through the demagnetization branch, which is the same as the prior art. However, in this embodiment, the demagnetization branch is different from that in the prior art. In the demagnetization branch, except for the reverse diode D1 (the anode of the reverse diode D1 is connected to the second end of the coil RLY, the cathode of the reverse diode D1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the first end of the coil RLY. It also includes a capacitor C1. The function of the capacitor C1 is to quickly absorb the energy generated by the remanence of the coil RLY and save it, that is, charging first, and then discharging through the discharge load, that is, discharging again. The specific process is as follows:

Demagnetization process:

When the moving and static contacts of the relay need to be disconnected, the switch device is turned off by a signal to turn off the switch device. At this time, the coil RLY generates a reverse electromotive force to charge the capacitor C1 through the reverse diode D1, and the residual magnetic energy is stored on the capacitor C1. It can be understood that with the continuous transfer of the residual magnetic energy, the voltage of the capacitor C1 will gradually increase, and the demagnetization voltage of the coil RLY at this time is the sum of the forward conduction voltage of the reverse diode D1 and the voltage of the capacitor C1, Therefore, the demagnetization speed of the coil RLY can be effectively accelerated and the relay bounce can be avoided. Compared with the prior art, the demagnetization voltage of the coil RLY in this embodiment increases the voltage of the capacitor C1 on the basis of the forward conduction voltage of the reverse diode D1, so that the demagnetization can be quickly realized.

Magnetizing process:

When the moving and static contacts of the relay need to be pulled in, the switching device is turned on by a signal to make the switching device turn on. At this time, the power supply circuit where the coil RLY is located is turned on, the coil RLY has a current passing through it, and the capacitor C1 discharges through the discharge load, so that the The pressure difference between its two ends is restored to zero, which ensures that the residual magnetic energy can continue to be absorbed during the next demagnetization.

The demagnetization circuit provided in this embodiment includes a demagnetization branch, a discharge load and a switching device, wherein the demagnetization branch is connected in parallel with both ends of the coil of the relay, and can absorb the residual magnetic energy of the coil during the demagnetization process. When demagnetization is required, the power supply circuit where the coil is located is disconnected by turning off the switching device, and the residual magnetism at both ends of the coil is absorbed by the demagnetization branch. Since the energy storage element capacitor is added to the demagnetization circuit, the capacitor can store residual magnetic energy. At this time, the demagnetization voltage is the sum of the voltage across the capacitor and the forward voltage of the reverse diode. Therefore, compared with only the As far as the forward voltage of the reverse diode is concerned, it can quickly demagnetize, thereby reliably eliminating the relay bounce phenomenon. In addition, the circuit structure is simple, the cost is low, and the application scenarios are wide.

As a preferred implementation manner, the switching device in the above embodiment is specifically a transistor Q1.

It can be understood that, in addition to the transistor Q1, a switch tube such as a MOS tube can also be used as a switch device. Compared with other devices, the transistor Q1 has a lower cost and has the function of current amplification. The switching signal, as a signal for controlling the on and off of the switching device, needs to be determined according to the type of the switching device, and the specific content will be well known to those skilled in the art, and will not be repeated herein.

As a preferred embodiment, the transistor Q1 is specifically an NPN transistor, the base of the NPN transistor is used as the input end of the switching signal, and the collector of the NPN transistor is connected to the common terminal formed by the coil RLY and the anode of the reverse diode D1 , the emitter of the NPN transistor is grounded.

As shown in Figure 2, the transistor Q1 is specifically an NPN transistor, and the corresponding switch signal is low level or high level. Specifically, when demagnetizing, the switch signal is low level, and the NPN transistor is turned off at this time. , when magnetized, the switch signal is high, and the NPN transistor is turned on at this time.

FIG. 3 is a circuit diagram of another demagnetization circuit of a relay provided by an embodiment of the present invention. As shown in FIG. 3 , the demagnetization circuit further includes a current limiting resistor R2 , which is disposed at the front end of the base of the NPN triode to serve as the input end of the switching signal. As a preferred embodiment, it also includes a voltage dividing resistor R3, one end of the voltage dividing resistor R3 is connected to the base of the NPN triode, and the other end of the voltage dividing resistor R3 is connected to the emitter of the NPN triode.

It can be understood that the selection of the resistance values of the current limiting resistor R2 and the voltage dividing resistor R3 needs to be selected according to the actual parameters of the circuit, which will not be repeated in this embodiment.

In the above embodiments, the demagnetization circuit of the relay is described in detail. The utility model also provides a relay including the demagnetization circuit. It can be understood that the structure of the relay body does not need any improvement, therefore, reference can be made to the prior art.

Since the relay provided in this embodiment includes a demagnetization circuit, the demagnetization circuit includes a demagnetization branch, a bleeder load and a switching device, wherein the demagnetization branch is connected in parallel with both ends of the coil of the relay, and can be used during the demagnetization process. absorbs the residual magnetic energy of the coil. When demagnetization is required, the power supply circuit where the coil is located is disconnected by turning off the switching device, and the residual magnetism at both ends of the coil is absorbed by the demagnetization branch. Since the energy storage element capacitor is added to the demagnetization circuit, the capacitor can store residual magnetic energy. At this time, the demagnetization voltage is the sum of the voltage across the capacitor and the forward voltage of the reverse diode. Therefore, compared with only the As far as the forward voltage of the reverse diode is concerned, it can quickly demagnetize, thereby reliably eliminating the relay bounce phenomenon.

The above is the relay and its demagnetization circuit provided by the present utility model. In addition, the present invention also provides a relay including the demagnetization circuit, which is introduced in detail. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of the present utility model, some improvements and modifications can also be made to the present utility model, and these improvements and modifications also fall into the protection of the claims of the present utility model. within the range.

It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities or operations. There is no such actual relationship or sequence between operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Claims (7)

1. the demagnetization circuit of a relay, it is characterized in that, comprise the demagnetization branch that is connected in parallel at both ends of the coil of the relay, discharge load and switching device, and described demagnetization branch comprises the capacitor and the reverse diode connected in series, The discharge load is connected in parallel with both ends of the capacitor to absorb the electric energy released by the capacitor. power supply circuit. 2 . The demagnetization circuit according to claim 1 , wherein the bleeder load is specifically a bleeder resistor. 3 . 3 . The demagnetization circuit according to claim 1 , wherein the switching device is a triode. 4 . 4. The demagnetization circuit according to claim 3, wherein the triode is specifically an NPN triode, the base of the NPN triode is used as the input end of the switching signal, and the collector of the NPN triode is used as the input end of the switching signal. The electrode is connected to the common terminal formed by the coil and the anode of the reverse diode, and the emitter of the NPN triode is grounded. 5 . The demagnetization circuit according to claim 4 , further comprising a current-limiting resistor, the current-limiting resistor being disposed at the front end of the base of the NPN triode to serve as the input end of the switching signal. 6 . 6 . The demagnetization circuit according to claim 5 , further comprising a voltage dividing resistor, one end of the voltage dividing resistor is connected to the base of the NPN triode, and the other end of the voltage dividing resistor is connected to the base of the NPN transistor. 7 . The emitter of the NPN transistor is connected. 7. A relay, comprising a relay body, characterized in that, further comprising the demagnetization circuit according to any one of claims 1-6.