CN214412693U

CN214412693U - AC output type solid relay

Info

Publication number: CN214412693U
Application number: CN202120678027.1U
Authority: CN
Inventors: 王子辉; 林育超
Original assignee: Kudom Electronics Technology Xiamen Co ltd
Current assignee: Kudom Electronics Technology Xiamen Co ltd
Priority date: 2021-04-02
Filing date: 2021-04-02
Publication date: 2021-10-15
Anticipated expiration: 2031-04-02

Abstract

The utility model discloses an exchange output type solid relay, including the opto-coupler, switch tube T1 and T2, fast switch-on circuit and fast turn-off circuit, switch tube T1 and T2 are MOS pipe or IGBT pipe, switch tube T1 and T2 reverse series connection constitute two-way switch-on circuit, concatenate between this exchange output type solid relay's two output, the control end of switch tube T1 and T2 and the control end of fast switch-on circuit and fast turn-off circuit connect the output of opto-coupler respectively, when the opto-coupler switches on, drive fast switch-on circuit, switch tube T1 and T2 switch on, when the fast switch-on circuit switches on, its inside energy storage unit discharges with the increase current that flows through switch tube T1 and T2 control end; when the optical coupler is not conducted, the quick turn-off circuit is driven to be conducted, the switching tubes T1 and T2 are driven to be turned off, and the quick turn-off circuit is used for discharging currents of the control ends of the switching tubes T1 and T2. The utility model discloses can realize the function that solid relay switches on fast and turn-off fast.

Description

AC output type solid relay

Technical Field

The utility model belongs to the technical field of solid relay, specifically relate to an alternating current output type solid relay.

Background

At present, the conventional ac output type solid-state relays are divided into a zero-crossing type and a random type, the type of solid-state relays are realized by a circuit combining an optical coupler and a silicon controlled rectifier, the circuit is shown in fig. 1, the circuit of the scheme has the phenomena that the circuit can not be quickly switched on and can not be quickly switched off, and the switching-on time of a common product is respectively as follows according to the working sequence shown in fig. 2: zero crossing type [1/2 voltage cycle +1ms max (maximum on time of circuit) ], random type [1ms max ]; the off-times are all 1/2 voltage cycles +1ms max.

In some practical application occasions, the solid relay is required to be capable of realizing rapid on and rapid off, the on time and the off time of the solid relay generally reach microsecond level, and the solid relay is required to be capable of realizing rapid on and rapid off in order to achieve accurate temperature control on a medical warm magnetic therapy apparatus.

Disclosure of Invention

An object of the utility model is to provide an exchange output type solid state relay is used for solving the technical problem that above-mentioned exists.

In order to achieve the above object, the utility model adopts the following technical scheme: an AC output type solid relay comprises an optical coupler, a switch tube T1, a switch tube T2, a quick switch-on circuit and a quick switch-off circuit, wherein the switch tube T1 and the switch tube T2 are MOS tubes or IGBT tubes, the switch tube T1 and the switch tube T2 are reversely connected in series to form a bidirectional switch-on circuit, the bidirectional switch-on circuit is connected between two output ends of the AC output type solid relay in series, a control end of the switch tube T1 and the switch tube T2, a control end of the quick switch-on circuit and a control end of the quick switch-off circuit are respectively connected with an output end of the optical coupler, when the optical coupler is connected, the quick switch-on circuit, the switch tube T1 and the switch tube T2 are driven to be connected, and when the quick switch-on circuit is connected, an energy storage unit inside the solid relay discharges to increase current flowing through the control ends of the switch tube T1 and the switch tube T2; when the optical coupler is not switched on, the quick turn-off circuit is driven to be switched on, the switching tube T1 and the switching tube T2 are driven to be turned off, and the quick turn-off circuit is used for discharging currents of the control ends of the switching tube T1 and the switching tube T2.

Further, the fast turn-on circuit is composed of an NPN triode Q2 and a capacitor C1, a first end of the capacitor C1 is connected to two output ends of the ac output type solid relay, a second end of the capacitor C1 is connected to a node between a switch tube T1 and a switch tube T2, a collector of the NPN triode Q2 is connected to a first end of the capacitor C1, an emitter of the NPN triode Q2 is connected to resistors R6 and R7 in series respectively and connected to a control end of the switch tube T1 and the switch tube T2, a resistor R5 is connected between a base and the emitter of the triode Q2 in parallel, and a base of the triode Q2 is connected to a positive output end of the optocoupler.

Furthermore, the solid-state relay further comprises diodes D1 and D2, and a first end of the capacitor C1 is connected in reverse series with the diodes D1 and D2 respectively and then connected with two output ends of the AC output type solid-state relay.

Furthermore, the quick turn-off circuit is formed by a PNP triode Q3.

Further, the optical coupler is a photovoltaic output type optical coupler.

Furthermore, the solid-state relay further comprises a pulse voltage suppression circuit, and the pulse voltage suppression circuit is connected between the two output ends of the alternating current output type solid-state relay.

Furthermore, the pulse voltage suppression circuit comprises TVS tubes D5 and D6, and the TVS tubes D5 and D6 are connected in series and then connected between two output ends of the AC output type solid state relay.

Further, the switch tube T1 and the switch tube T2 are MOS tubes, and a voltage regulator D3 is further connected between the gates and the sources of the switch tube T1 and the switch tube T2.

The utility model has the advantages of:

the utility model discloses can realize the function that solid relay switches on fast and turn-off fast, and circuit structure is simple, easily realizes.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a circuit diagram of a conventional ac output type solid-state relay;

fig. 2 is a timing chart of the operation of a conventional ac output type solid-state relay;

fig. 3 is a circuit diagram of an embodiment of the present invention.

Detailed Description

To further illustrate the embodiments, the present invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The present invention will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 3, an ac output type solid-state relay includes an optical coupler a1, a switch tube T1, a switch tube T2, a fast turn-on circuit and a fast turn-off circuit, where the switch tube T1 and the switch tube T2 are MOS tubes, the MOS tube T1 and the MOS tube T2 are reversely connected in series to form a bidirectional turn-on switch circuit, and are connected in series between two output terminals 1 and 2 of the ac output type solid-state relay, a gate of the MOS tube T1 is connected in series with resistors R6 and R5 in sequence and then connected with an output terminal of the optical coupler a1, a gate of the MOS tube T2 is connected in series with resistors R7 and R5 in sequence and connected with an output terminal of the optical coupler a1, and a control terminal of the fast turn-on circuit and a control terminal of the fast turn-off circuit are connected with an output terminal of the optical coupler a1, when the optical coupler is switched on, the quick switching-on circuit, the MOS tube T1 and the MOS tube T2 are driven to be switched on, when the quick switching-on circuit is switched on, the energy storage units inside the MOS tube T1 and the MOS tube T2 are discharged to increase the current flowing through the grid electrodes of the MOS tubes; when the optical coupler is not switched on, the quick turn-off circuit is driven to be switched on, the MOS tube T1 and the MOS tube T2 are driven to be turned off, and the quick turn-off circuit is used for discharging currents of grids of the MOS tube T1 and the MOS tube T2.

In this embodiment, the MOS transistors T1 and T2 are preferably depletion NMOS transistors, which is easy to implement, the drain of the MOS transistor T1 is connected to the output terminal 1 of the ac output type solid-state relay, the source of the MOS transistor T1 is connected to the source of the MOS transistor T2, the drain of the MOS transistor T2 is connected to the output terminal 2 of the ac output type solid-state relay, the gate of the MOS transistor T1 is sequentially connected in series with the resistors R6 and R5 and then connected to the output terminal of the optical coupler a1, and the gate of the MOS transistor T2 is sequentially connected in series with the resistors R7 and R5 and connected to the output terminal of the optical coupler a1, but not limited thereto. In other embodiments, the switch transistor T1 and the switch transistor T2 may also be implemented by other MOS transistors or IGBT transistors.

In this specific embodiment, the optical coupler a1 is preferably a photovoltaic output type optical coupler, the withstand voltage is good, the structure is simple, the positive input end of the optical coupler a1 is sequentially connected with the resistors R3, R2 and R1 are connected with the positive end 3+ of the control signal, the negative input end of the optical coupler a1 is connected with the negative end 4-of the control signal, the resistor R4 is connected between the positive input end and the negative input end of the optical coupler a1, the negative output end of the optical coupler a1 is connected with a node between the MOS transistor T1 and the T2, but not limited thereto, in some embodiments, the optical coupler a1 can also be realized by adopting other optical couplers.

In this embodiment, the fast turn-on circuit is formed by an NPN transistor Q2 and a capacitor C1, a first end of the capacitor C1 is connected to two output terminals 1 and 2 of the ac output type solid-state relay, a second end of the capacitor C1 is connected to a node (i.e., sources of a MOS transistor T1 and a MOS transistor T2) between a MOS transistor T1 and a MOS transistor T2, a collector of the NPN transistor Q2 is connected to a first end of the capacitor C1, an emitter of the NPN transistor Q2 is connected to NPN resistors R6 and R7 in series respectively and to gates of the MOS transistor T1 and the MOS transistor T2, a base and an emitter of the transistor Q2 are connected to a resistor R5 in parallel, and a base of the transistor Q2 is connected to a positive output terminal of the optocoupler a 1. By adopting the quick connection circuit, the circuit structure is simple, the realization is easy, the cost is low, but not limited to the above, and in some embodiments, the quick connection circuit can also be realized by adopting other existing energy storage circuits and switch circuits.

The resistors R6 and R7 play a role in current limiting protection so as to protect the MOS transistors T1 and T2 and improve safety and reliability.

Furthermore, in this embodiment, the solid-state relay further includes diodes D1 and D2, the first end of the capacitor C1 is connected to the cathodes of the diodes D1 and D2, respectively, and the anodes of the diodes D1 and D2 are connected to the two output terminals 1 and 2 of the ac output type solid-state relay, respectively, so as to prevent the capacitor C1 from discharging, and apply a voltage to the MOS transistor T1 and the MOS transistor T2, thereby protecting the MOS transistor T1 and the MOS transistor T2, and improving safety and reliability.

In this embodiment, the fast turn-off is preferably implemented by using a PNP transistor Q3, an emitter of the PNP transistor Q3 is respectively connected in series with resistors R6 and R7 to the gates of the MOS transistor T1 and the MOS transistor T2, a resistor R5 is connected in parallel between the emitter and the base of the transistor Q3, the base of the transistor Q3 is connected to the positive output end of the optocoupler a1, and a collector of the PNP transistor Q3 is connected to a node between the MOS transistor T1 and the MOS transistor T2 (i.e., the sources of the MOS transistor T1 and the MOS transistor T2). But not limited thereto, in other embodiments, the fast turn-off may be implemented by using other existing switch circuits.

In the embodiment, a voltage regulator tube D3 is connected between the grid electrodes and the source electrodes of the MOS tube T1 and the MOS tube T2, so that the working stability of the MOS tube T1 and the MOS tube T2 is improved and the MOS tube T1 and the MOS tube T2 are protected.

In this embodiment, a voltage regulator D4 is further connected between the positive output end and the negative output end of the optical coupler a1, so as to protect the output end of the optical coupler a 1.

Further, in this embodiment, the solid-state relay further includes a pulse voltage suppression circuit, and the pulse voltage suppression circuit is connected between the two output terminals 1 and 2 of the ac output type solid-state relay. When the solid relay is under inductive load, an overvoltage pulse is applied to two output ends 1 and 2 of the AC output type solid relay when the solid relay is turned off, and the pulse voltage suppression circuit has the function of suppressing the voltage of the overvoltage pulse when the overvoltage pulse occurs, so that the overvoltage pulse is prevented from breaking through the MOS transistor T1 and the MOS transistor T2, and the safety and the reliability are improved.

In this embodiment, the pulse voltage suppression circuit includes TVS transistors D5 and D6, and TVS transistors D5 and D6 are connected in series and then connected between two output terminals 1 and 2 of the ac output type solid state relay.

The working principle is as follows:

the fast switching working principle is as follows: when control signals are applied to the positive end 3+ and the negative end 4 of the control signal, the optical coupler A1 is conducted to drive the NPN triode Q2 to be conducted, the capacitor C1 discharges through the NPN triode Q2, current flowing through the grids of the MOS transistor T1 and the MOS transistor T2 is increased, time for the MOS transistor T1 and the MOS transistor T2 to reach threshold voltage VGS required by conduction is shortened, and therefore rapid conduction of the MOS transistor T1 and the MOS transistor T2 is accelerated.

The working principle of quick turn-off is as follows: when the control signals are removed from the positive end 3+ and the negative end 4-, the optocoupler A1 is not conducted to drive the PNP triode Q3 to be conducted, the current of the grid electrodes of the MOS transistor T1 and the MOS transistor T2 is quickly discharged, the time for the voltage between the grid electrodes and the source electrodes of the MOS transistor T1 and the MOS transistor T2 to be reduced to 0V is shortened, and therefore the quick turn-off of the MOS transistor T1 and the MOS transistor T2 is accelerated.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An alternating current output type solid-state relay characterized in that: the high-speed switching-on circuit comprises an optical coupler, a switching tube T1, a switching tube T2, a quick switching-on circuit and a quick switching-off circuit, wherein the switching tube T1 and the switching tube T2 are MOS tubes or IGBT tubes, the switching tube T1 and the switching tube T2 are reversely connected in series to form a bidirectional switching-on switching circuit, the bidirectional switching-on switching circuit is connected between two output ends of the alternating current output type solid relay in series, a control end of the switching tube T1 and the switching tube T2, a control end of the quick switching-on circuit and a control end of the quick switching-off circuit are respectively connected with an output end of the optical coupler, when the optical coupler is switched on, the quick switching-on circuit, the switching tube T1 and the switching tube T2 are driven to be switched on, and when the quick switching-on circuit is switched on, an energy storage unit inside the optical coupler discharges to increase current flowing through the control ends of the switching tube T1 and the switching tube T2; when the optical coupler is not switched on, the quick turn-off circuit is driven to be switched on, the switching tube T1 and the switching tube T2 are driven to be turned off, and the quick turn-off circuit is used for discharging currents of the control ends of the switching tube T1 and the switching tube T2.

2. An ac output type solid-state relay according to claim 1, wherein: the fast connection circuit is composed of an NPN triode Q2 and a capacitor C1, a first end of the capacitor C1 is connected with two output ends of the alternating current output type solid relay respectively, a second end of the capacitor C1 is connected with a node between a switch tube T1 and a switch tube T2, a collector of the NPN triode Q2 is connected with a first end of the capacitor C1, an emitter of the NPN triode Q2 is connected with resistors R6 and R7 in series respectively and connected with a control end of the switch tube T1 and a control end of the switch tube T2, a resistor R5 is connected between a base and the emitter of the triode Q2 in parallel, and a base of the NPN triode Q2 is connected with a positive output end of the optocoupler.

3. An ac output type solid-state relay according to claim 2, wherein: the solid-state relay further comprises diodes D1 and D2, and the first end of the capacitor C1 is connected with the diodes D1 and D2 in a reverse-direction series mode respectively and then connected with the two output ends of the alternating current output type solid-state relay.

4. An ac output type solid-state relay according to claim 1, wherein: the quick turn-off circuit is formed by a PNP triode Q3.

5. An ac output type solid-state relay according to claim 1, wherein: the optical coupler is a photovoltaic output type optical coupler.

6. An ac output type solid-state relay according to claim 1, wherein: the solid relay also comprises a pulse voltage suppression circuit, wherein the pulse voltage suppression circuit is connected between the two output ends of the alternating current output type solid relay.

7. An ac output type solid-state relay according to claim 6, wherein: the pulse voltage suppression circuit comprises TVS tubes D5 and D6, and the TVS tubes D5 and D6 are connected between two output ends of the alternating current output type solid relay after being connected in series.

8. An ac output type solid-state relay according to claim 1, wherein: the switch tube T1 and the switch tube T2 are both MOS tubes, and a voltage-stabilizing tube D3 is connected between the grid electrodes and the source electrodes of the switch tube T1 and the switch tube T2.