阅读说明：本技术 一种pwm控制型继电器 (PWM control type relay ) 是由 谢林波 宁艳艳 海翔 郭竟 任海峰 余鸿坤 于 2019-11-08 设计创作，主要内容包括：本发明公开一种PWM控制型继电器,由隔离保护电路,选频电路,固体继电器后级通用电路和输出电路组成。隔离保护电路的输入端形成PWM控制型继电器的控制输入端,并与PWM控制信号连接；隔离保护电路的输出端连接选频电路的输入端,选频电路的输出端连接固体继电器后级通用电路的输入端,固体继电器后级通用电路的输出端连接输出电路的输入端,输出电路的输出端形成PWM控制型继电器的负载输出端,并与负载连接。本发明省掉了中间转换环节简化电路结构,并能在特定的电压下以频率作为控制量进行控制,当频率过低或过高继电器均无法接通,当撤掉控制信号或一直施加直流电压时继电器关断,实现了小信号控制大负载的目标。(The invention discloses a PWM control type relay, which consists of an isolation protection circuit, a frequency selection circuit, a post-stage general circuit of a solid relay and an output circuit. The input end of the isolation protection circuit forms the control input end of the PWM control type relay and is connected with the PWM control signal; the output end of the isolation protection circuit is connected with the input end of the frequency selection circuit, the output end of the frequency selection circuit is connected with the input end of the solid relay rear-stage general circuit, the output end of the solid relay rear-stage general circuit is connected with the input end of the output circuit, and the output end of the output circuit forms the load output end of the PWM control type relay and is connected with a load. The invention omits an intermediate conversion link, simplifies the circuit structure, can control by taking the frequency as a control quantity under specific voltage, can not be switched on when the frequency is too low or too high, and can be switched off when a control signal is removed or direct current voltage is always applied, thereby realizing the aim of controlling a large load by a small signal.)

1. A PWM control type relay is characterized by comprising an isolation protection circuit, a frequency selection circuit, a post-stage general circuit of a solid relay and an output circuit;

the input end of the isolation protection circuit forms the control input end of the PWM control type relay and is connected with the PWM control signal; the output end of the isolation protection circuit is connected with the input end of the frequency selection circuit, the output end of the frequency selection circuit is connected with the input end of the solid relay rear-stage general circuit, the output end of the solid relay rear-stage general circuit is connected with the input end of the output circuit, and the output end of the output circuit forms the load output end of the PWM control type relay and is connected with a load.

2. The PWM controlled relay according to claim 1, wherein the isolation protection circuit is composed of a transient suppression diode V1, resistors R1-R2, a diode V2, and a transistor V3;

the negative electrode of the transient suppression diode V1, one end of the resistors R1 and R2 and the positive electrode of the diode V2 are connected to form the positive electrode of the input end of the isolation protection circuit; the cathode of the diode V2 is connected with the emitter of the triode V3 to form the anode of the output end of the isolation protection circuit; the anode of the transient suppression diode V1, the other end of the resistor R1 and the collector of the triode V3 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the base of the transistor V3 is connected to the other end of the resistor R2.

3. The PWM controlled relay according to claim 1, wherein the isolation protection circuit is composed of a transient suppression diode V1, resistors R1, R2, R4-R6, and triodes V2-V4;

one end of the resistor R1 forms the anode of the input end of the isolation protection circuit; the other end of the resistor R1 is connected with one end of a resistor R2, the negative electrode of a transient suppression diode V1 and the base electrode of a triode V2; the other end of the resistor R2, the anode of the transient suppression diode V1, the emitter of the triode V2 and the emitter of the triode V4 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the collector of the triode V2 is connected with one end of the resistors R4-R6; the other end of the resistor R6 is connected with the emitter of the triode V4 and then is connected with a power supply VCC; the other end of the resistor R4 is connected with the base of the triode V3; the other end of the resistor R5 is connected with the base of the triode V4; the collector of the triode V3 is connected with the collector of the triode V4 to form the anode of the output end of the isolation protection circuit.

4. The relay according to claim 1, wherein the frequency selecting circuit comprises a capacitor C1, a resistor R3, and a transformer T;

one end of the capacitor C1 forms the anode of the input end of the frequency selection circuit, and one end of the resistor R3 forms the cathode of the input end of the frequency selection circuit; the other end of the capacitor C1 and the other end of the resistor R3 are respectively connected with two output ends of the transformer T; and the two output ends of the transformer T form the positive and negative electrodes of the output end of the frequency selection circuit.

5. The PWM control type relay according to claim 1, wherein the output circuit is composed of field effect transistors Q1-Q2, and a bidirectional transient suppression diode V12;

the drain electrode of the field effect transistor Q1 is connected with one end of a bidirectional transient suppression diode V12 to form one end of the output circuit; the drain electrode of the field effect transistor Q2 is connected with the other end of the bidirectional transient suppression diode V12 to form the other end of the output circuit; the source electrode of the field effect transistor Q1 is connected with the source electrode of the field effect transistor Q2 to form a control negative electrode of the input end of the output circuit; the gate of fet Q1 forms one control positive of the input to the circuit, and the gate of fet Q2 forms the other positive of the input to the circuit.

Technical Field

The invention relates to the technical field of solid relays, in particular to a PWM (pulse-width modulation) control type relay.

Background

With the development of aviation, aerospace, electronic and computer control technologies, most of solid relays used in current systems are voltage-driven type or current-driven type. However, with the use of miniaturized, integrated and highly dense devices, control chips represented by FPGA chips are increasingly used in electronic design. Because the output signal of the control chip is used as a driving signal to drive a post-stage circuit, signal amplification and signal isolation are generally needed, so that how to simplify the circuit and control is realized, the number of intermediate links is reduced, and the general-purpose module is integrated into the development trend.

Disclosure of Invention

The invention provides a PWM control type relay, which can save an intermediate conversion link and simplify a circuit structure, and can realize the aim of controlling a large load by a small signal.

In order to solve the problems, the invention is realized by the following technical scheme:

a PWM control relay is composed of an isolation protection circuit, a frequency selection circuit, a post-stage general circuit of a solid relay and an output circuit; the input end of the isolation protection circuit forms the control input end of the PWM control type relay and is connected with the PWM control signal; the output end of the isolation protection circuit is connected with the input end of the frequency selection circuit, the output end of the frequency selection circuit is connected with the input end of the solid relay rear-stage general circuit, the output end of the solid relay rear-stage general circuit is connected with the input end of the output circuit, and the output end of the output circuit forms the load output end of the PWM control type relay and is connected with a load.

In the scheme, the isolation protection circuit consists of a transient suppression diode V1, resistors R1-R2, a diode V2 and a triode V3; the negative electrode of the transient suppression diode V1, one end of the resistors R1 and R2 and the positive electrode of the diode V2 are connected to form the positive electrode of the input end of the isolation protection circuit; the cathode of the diode V2 is connected with the emitter of the triode V3 to form the anode of the output end of the isolation protection circuit; the anode of the transient suppression diode V1, the other end of the resistor R1 and the collector of the triode V3 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the base of the transistor V3 is connected to the other end of the resistor R2.

In the scheme, the isolation protection circuit consists of a transient suppression diode V1, resistors R1, R2, R4-R6 and triodes V2-V4; one end of the resistor R1 forms the anode of the input end of the isolation protection circuit; the other end of the resistor R1 is connected with one end of a resistor R2, the negative electrode of a transient suppression diode V1 and the base electrode of a triode V2; the other end of the resistor R2, the anode of the transient suppression diode V1, the emitter of the triode V2 and the emitter of the triode V4 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the collector of the triode V2 is connected with one end of the resistors R4-R6; the other end of the resistor R6 is connected with the emitter of the triode V4 and then is connected with a power supply VCC; the other end of the resistor R4 is connected with the base of the triode V3; the other end of the resistor R5 is connected with the base of the triode V4; the collector of the triode V3 is connected with the collector of the triode V4 to form the anode of the output end of the isolation protection circuit.

In the scheme, the frequency selection circuit consists of a capacitor C1, a resistor R3 and a transformer T; one end of the capacitor C1 forms the anode of the input end of the frequency selection circuit, and one end of the resistor R3 forms the cathode of the input end of the frequency selection circuit; the other end of the capacitor C1 and the other end of the resistor R3 are respectively connected with two output ends of the transformer T; and the two output ends of the transformer T form the positive and negative electrodes of the output end of the frequency selection circuit.

In the scheme, the output circuit consists of field effect transistors Q1-Q2 and a bidirectional transient suppression diode V12; the drain electrode of the field effect transistor Q1 is connected with one end of a bidirectional transient suppression diode V12 to form one end of the output circuit; the drain electrode of the field effect transistor Q2 is connected with the other end of the bidirectional transient suppression diode V12 to form the other end of the output circuit; the source electrode of the field effect transistor Q1 is connected with the source electrode of the field effect transistor Q2 to form a control negative electrode of the input end of the output circuit; the gate of fet Q1 forms one control positive of the input to the circuit, and the gate of fet Q2 forms the other positive of the input to the circuit.

Compared with the prior art, the invention has the following characteristics:

1. the control end and the load end are directly associated, so that an intermediate conversion link is omitted, and the circuit becomes simpler;

2. the relay is controlled by taking the frequency as a control quantity under a specific voltage, the relay cannot be switched on when the frequency is too low or too high, and the relay is switched off when a control signal is removed or direct-current voltage is always applied, so that the aim of controlling a large load by a small signal is fulfilled.

3. The transient suppression diode is added in the isolation protection circuit at the input end, so that the control chip is prevented from being broken down by the reverse high voltage of the back end circuit, and the anti-static capability of the relay can be improved;

4. the output circuit of the output end has no polarity, and a transient suppression diode is added to protect the output field effect transistor, prevent voltage breakdown and improve the anti-static capability of the relay.

Drawings

Fig. 1 is a schematic block diagram of a PWM-controlled relay.

Fig. 2a) to 2b) are schematic circuit diagrams of a PWM-controlled relay.

Fig. 3a) to 3d) are schematic diagrams of application of the PWM control type relay.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to specific examples.

A PWM control type relay is composed of an isolation protection circuit, a frequency selection circuit, a post-stage general circuit of a solid relay and an output circuit, as shown in figure 1. The input end of the isolation protection circuit forms the control input end of the PWM control type relay and is connected with the PWM control signal; the output end of the isolation protection circuit is connected with the input end of the frequency selection circuit, the output end of the frequency selection circuit is connected with the input end of the solid relay rear-stage general circuit, the output end of the solid relay rear-stage general circuit is connected with the input end of the output circuit, and the output end of the output circuit forms the load output end of the PWM control type relay and is connected with a load. The isolation protection circuit is a first-stage circuit of the PWM control type relay, the voltage is clamped at a lower voltage level through a preceding-stage transient suppression diode to prevent a controller connected with the isolation protection circuit from being subjected to reverse voltage breakdown, meanwhile, the control end of the PWM control type relay is prevented from being subjected to overvoltage impact, and the anti-static capability of the control end of the relay is improved. The frequency selection circuit amplifies the control signal component with the selected specific frequency and transmits the amplified control signal component to the post-stage general circuit of the solid relay through the magnetic isolator. The post-stage general circuit of the solid relay realizes the functions of rectification, GS electrode voltage limiting, GS junction capacitance electricity releasing and the like. The output circuit is responsible for the external output of the PWM control type relay, has a voltage transient suppression function and has strong adaptability to inductive loads.

The isolation protection circuit of the invention comprises two structures:

an isolation protection circuit is composed of a transient suppression diode V1, resistors R1-R2, a diode V2 and a triode V3, as shown in FIG. 2 a). The negative electrode of the transient suppression diode V1, one end of the resistors R1 and R2 and the positive electrode of the diode V2 are connected to form the positive electrode of the input end of the isolation protection circuit; the cathode of the diode V2 is connected with the emitter of the triode V3 to form the anode of the output end of the isolation protection circuit; the anode of the transient suppression diode V1, the other end of the resistor R1 and the collector of the triode V3 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the base of the transistor V3 is connected to the other end of the resistor R2. The isolation protection circuit is suitable for occasions where the controller directly drives the PWM control type relay and the driving current is small, has high requirements on the Q value and the amplification factor of the frequency selection circuit, and is narrow in frequency band.

The other isolation protection circuit consists of a transient suppression diode V1, resistors R1, R2, R4-R6 and triodes V2-V4, as shown in FIG. 2 b). One end of the resistor R1 forms the anode of the input end of the isolation protection circuit; the other end of the resistor R1 is connected with one end of a resistor R2, the negative electrode of a transient suppression diode V1 and the base electrode of a triode V2; the other end of the resistor R2, the anode of the transient suppression diode V1, the emitter of the triode V2 and the emitter of the triode V4 are connected to form the cathode of the input end and the cathode of the output end of the isolation protection circuit; the collector of the triode V2 is connected with one end of the resistors R4-R6; the other end of the resistor R6 is connected with the emitter of the triode V4 and then is connected with a power supply VCC; the other end of the resistor R4 is connected with the base of the triode V3; the other end of the resistor R5 is connected with the base of the triode V4; the collector of the triode V3 is connected with the collector of the triode V4 to form the anode of the output end of the isolation protection circuit. The isolation protection circuit is suitable for occasions where the driving current is controlled to be weak and the driving power needs to be amplified, and has low requirements on the Q value and the amplification factor of the frequency selection circuit and a wider frequency band under the condition of proper power supply.

The frequency selection circuit of the invention is composed of a capacitor C1, a resistor R3 and a transformer T, as shown in figures 2a) and 2 b). One end of the capacitor C1 forms the anode of the input end of the frequency selection circuit, and one end of the resistor R3 forms the cathode of the input end of the frequency selection circuit; the other end of the capacitor C1 and the other end of the resistor R3 are respectively connected with two output ends of the transformer T; and the two output ends of the transformer T form the positive and negative electrodes of the output end of the frequency selection circuit. The frequency selection circuit can amplify the control signal with specific frequency and transmit the amplified control signal to the post-stage circuit of the solid relay for post-processing. The specific frequency calculation formula is as follows:

magnetic isolator secondary output voltage effective value U₀The following equation:

wherein N is the magnetic isolation secondary primary boost ratio, U_fThe frequency of the PWM control signal is transmitted to the frequency selection circuit, the effective value of the amplitude component is f, and R is the equivalent resistance of the loop.

The output circuit of the invention consists of field effect transistors Q1-Q2 and a bidirectional transient suppression diode V12, as shown in figures 2a) and 2 b). The drain electrode of the field effect transistor Q1 is connected with one end of a bidirectional transient suppression diode V12 to form one end of the output circuit; the drain electrode of the field effect transistor Q2 is connected with the other end of the bidirectional transient suppression diode V12 to form the other end of the output circuit; the source electrode of the field effect transistor Q1 is connected with the source electrode of the field effect transistor Q2 to form a control negative electrode of the input end of the output circuit; the gate of fet Q1 forms one control positive of the input to the circuit, and the gate of fet Q2 forms the other positive of the input to the circuit. The output end positive pole of the solid relay post-stage general circuit is divided into two lines from one point, the two lines are connected with a resistor and then connected to the grid electrodes of 2 field effect transistors Q1 and Q2 of the output circuit, namely, the input end of the output circuit adopts a mode of 2 control positive ends, and the purpose is to prevent the field effect transistors from self-oscillation. When the output circuit works normally, the working power supply voltage is required to be smaller than the maximum reverse working voltage of the bidirectional transient suppression diode, and the maximum clamping voltage of the bidirectional transient suppression diode is smaller than the breakdown voltage of the output field effect tube. In addition, the output circuit has strong adaptability to inductive load.

An application circuit of the invention is shown in fig. 3a) and 3b), wherein the anode of the input end of the PWM control type relay is directly connected with the control chip, and the cathode of the input end is connected with the control ground; one end of the output end of the PWM control type relay is connected with the anode of the power supply, the other end of the output end of the PWM control type relay is connected with one end of the load, and the cathode of the power supply and the other end of the load are simultaneously grounded. The application mode can realize the aim of controlling a large load by a small signal, and the application method has high requirements on the Q value and the amplification factor of the relay and has a narrow frequency band.

Another applied circuit of the present embodiment is shown in fig. 3c) and 3d), wherein the positive electrode of the input end of the PWM controlled relay is directly connected to the control chip, and the negative electrode of the input end is connected to the control ground; one end of the output end of the PWM control type relay is connected with one end of the load, the other end of the load is connected with the anode of the power supply, and the cathode of the power supply and the other end of the output end of the PWM control type relay are simultaneously grounded. The relay in the application mode needs to provide an additional working power supply during normal work, the proper working power supply voltage can reduce the requirements on the Q value and the amplification factor of the relay, and the frequency band is wider.

It should be noted that, although the above-mentioned embodiments of the present invention are illustrative, the present invention is not limited thereto, and thus the present invention is not limited to the above-mentioned embodiments. Other embodiments, which can be made by those skilled in the art in light of the teachings of the present invention, are considered to be within the scope of the present invention without departing from its principles.