AC Input Intermediate Relay Circuit

Abstract

The present invention provides an anti - AC input intermediate relay circuit, comprising: the positive terminal of a DC power supply; the negative terminal of the DC power supply; a pre - stage switch relay; a controlled relay; an anti - AC device for controlling the operation of the pre - stage switch relay according to the type of input power supply; the anti - AC device has a switch circuit, one end of the switch circuit is connected to the negative terminal of the DC power supply, the other end is connected to the relay coil of the pre - stage switch relay, and the other end of the relay coil of the pre - stage switch relay is connected to the positive terminal of the DC power supply. The anti - AC device controls the switch circuit to turn off according to the detected AC input, and controls the switch circuit to turn on according to the detected DC input. The anti - AC input intermediate relay circuit of the present invention can remain non - operative during AC input, and reliably operate after a preset time delay during DC input, and has the advantage of not burning when the DC is reversely connected.

Description

Technical Field

[0001] The present invention relates to the technical field of relays, and more particularly to an anti - AC input intermediate relay circuit. Background Art

[0002] At present, high - power DC intermediate relays used in State Grid high - voltage lines have relatively high requirements for anti - interference. Especially when AC power is input or there is input disturbance, they should be able to operate reliably or not operate, and when DC is reversely connected, the relay should not operate or respond, so as to achieve stable and reliable operation. Summary of the Invention

[0003] According to the first aspect of the improvement of the present invention, an anti - AC input intermediate relay circuit is proposed, including: the positive terminal of the DC power supply; the negative terminal of the DC power supply; a pre - stage switch relay; a first relay, as the controlled relay, the coil of the first relay is connected between the negative terminal of the DC power supply and the output contact of the pre - stage switch relay;

[0004] An anti - AC device, connected between the positive terminal and the negative terminal of the DC power supply, is used to control the operation of the pre - stage switch relay according to the type of the input power supply;

[0005] Wherein, the anti - AC device has a switch circuit, one end of the switch circuit is connected to the negative terminal of the DC power supply, the other end is connected to the relay coil of the pre - stage switch relay, and the other end of the relay coil of the pre - stage switch relay is connected to the positive terminal of the DC power supply.

[0006] The anti - AC device controls the switch circuit to turn off according to the detected AC input, and controls the switch circuit to turn on according to the detected DC input.

[0007] In an optional embodiment, the anti - AC input intermediate relay circuit includes two controlled relays, namely a first relay and a second relay, and the coils of the first relay and the second relay are connected in series between the negative terminal of the DC power supply and the output contact of the pre - stage switch relay.

[0008] As a preferred embodiment, the anti - AC device further includes a control circuit for input delay, and the control circuit is connected to the switch circuit to control the turn - off / turn - on of the switch circuit.

[0009] Preferably, the control circuit for input delay includes a first resistor, a first capacitor and a control IC. The first resistor and the first capacitor are connected in series between the negative terminal of the DC power supply and the power supply terminal VCC. The first resistor and the first capacitor form a delay time control circuit for controlling the delay time T;

[0010] The TRIG port and the THRES port of the control IC are respectively connected between a first resistor and a first capacitor, and the OUT port of the control IC outputs to the switching circuit.

[0011] Preferably, the switching circuit includes a second resistor, a first zener diode, and an N-type MOS transistor. The OUT port of the control IC is connected to the gate of the N-type MOS transistor. The source of the N-type MOS transistor is connected to the negative terminal of the DC power supply. A second resistor and a first zener diode are also connected in parallel between the gate of the N-type MOS transistor and the negative terminal of the DC power supply. The drain of the N-type MOS transistor outputs to the relay coil of the pre-stage switching relay.

[0012] The anti-ac input intermediate relay circuit proposed by the present invention does not operate or respond reliably when the input is AC, while when the input is DC, after a predetermined time delay, the pre-stage switching relay operates reliably to control the operation of the post-stage controlled relay, achieving the effect of anti-DC input interference. At the same time, it has the function of not operating and not burning when the DC input is reverse-connected.

[0013] It should be understood that all combinations of the foregoing concepts and additional concepts described in more detail below can be regarded as part of the inventive subject matter of the present disclosure as long as such concepts do not conflict with each other. In addition, all combinations of the claimed subject matter are regarded as part of the inventive subject matter of the present disclosure.

[0014] The foregoing and other aspects, embodiments, and features of the teachings of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of exemplary embodiments, will be apparent from the following description or will be learned through practice of the specific embodiments according to the teachings of the present invention. Description of the Drawings

[0015] The drawings are not intended to be drawn to scale. In the drawings, each identical or approximately identical component shown in each figure may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the drawings, wherein:

[0016] Figure 1 is a schematic diagram of the anti-ac input intermediate relay circuit according to an embodiment of the present invention.

[0017] Figure 2 is a schematic diagram of the anti-ac device according to an exemplary embodiment of the present invention. Detailed Embodiments

[0018] In order to better understand the technical content of the present invention, specific embodiments are given below in conjunction with the accompanying drawings for illustration.

[0019] Aspects of the present invention are described with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to cover all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. Additionally, some aspects of the present disclosure can be used alone or in any suitable combination with other aspects of the present disclosure.

[0020] Combined with Figure 1 、 Figure 2 The anti - AC input intermediate relay circuit shown in the figure includes a positive terminal 111 of a DC power supply and a negative terminal 112 of the DC power supply, which are used as input interfaces for power input.

[0021] Combined with Figure 1 The anti - AC input intermediate relay circuit shown in the figure further includes a pre - stage switch relay KM and at least one controlled relay. The coil of the controlled relay is connected between the negative terminal 120 of the DC power supply and the output contact of the pre - stage switch relay KM, and the coil is powered on by the action of the contact of the pre - stage switch relay KM.

[0022] In an embodiment of the present invention, taking two controlled relays, namely the first relay KM1 and the second relay KM2, as an example, in a preferred example, the two controlled relays KM1 and KM2 are usually relays with the same model parameters.

[0023] Combined with Figure 1 The anti - AC input intermediate relay circuit shown in the figure further includes an anti - AC device 120, which is connected between the positive terminal 111 of the DC power supply and the negative terminal 112 of the DC power supply, and is used to control the action of the pre - stage switch relay KM according to the input power type, that is, alternating current or direct current.

[0024] The anti - AC device 120 has a switch circuit 122. One end of the switch circuit 122 is connected to the negative pole 112 of the DC power supply, and the other end is connected to the relay coil of the pre - stage switch relay KM. The other end of the relay coil of the pre - stage switch relay KM is connected to the positive terminal 111 of the DC power supply.

[0025] Thus, the anti - AC device 120 detects whether the input is direct current or alternating current, and when detecting a DC input, controls the switch circuit to turn off, while when detecting a DC input, controls the switch circuit 122 to conduct, so that the relay coil of the pre - stage switch relay KM is powered on and makes it operate reliably.

[0026] As a preferred mode, the AC resistance device 120 controls the switch circuit 122 to turn off according to the detected AC input, and controls the switch circuit 122 to turn on according to the detected DC input.

[0027] Combined with Figure 1 As shown, the other end of the switch circuit 122 is connected to the relay coil of the pre-stage switch relay KM through a series voltage-dividing resistor RQ1. The voltage-dividing resistor RQ1 serves as the voltage-dividing resistor of the pre-stage switch relay KM.

[0028] Combined with Figure 1 As shown, the other end of the switch circuit 122 is connected in series with a starting resistor RP1 to the normally closed contact of the pre-stage switch relay KM and connected to the positive terminal 111 of the DC power supply. Thus, when the pre-stage switch relay KM operates effectively, the starting resistor RP1 (5W) serves as the starting resistor of the controlled relays (KM1, KM2) to ensure that the starting power is greater than or equal to 5W.

[0029] Combined with Figure 1 In the embodiment, a protection diode D2 is further provided between the positive terminal 111 of the DC power supply and the relay coil of the pre-stage switch relay KM. The positive electrode of the protection diode D2 is connected to the positive terminal 111 of the DC power supply, and its negative electrode is connected to the relay coil of the pre-stage switch relay KM. Thus, by providing the protection diode D2, it plays a role of not burning when directly reverse-connected.

[0030] Combined with Figure 1 、 2 As shown, the AC resistance device 120 further includes an input delay control circuit 121. The input delay control circuit 121 is connected to the switch circuit 122 and is used to control the turn-off / turn-on of the switch circuit 122.

[0031] Combined with Figure 2 As shown in the example, the input delay control circuit 121 includes a first resistor R1, a first capacitor C1, and a control IC 124. The first resistor R1 and the first capacitor C1 are connected in series between the negative terminal 112 of the DC power supply and the power supply terminal VCC. The power supply terminal VCC can be determined according to the selected control IC model. In the embodiment of the present invention, the control IC selects the TLC555 timer.

[0032] Thus, combined with Figure 2 , the first resistor R1 and the first capacitor C1 form a delay time control circuit for controlling the delay duration T. In the embodiment of the present invention, the delay time is controlled to be about 15 ms by selecting appropriate first resistor R1 and first capacitor C1.

[0033] As Figure 2, the TRIG port and the THRES port of the control IC 124 are respectively connected between the first resistor R1 and the first capacitor C1, and the OUT port of the control IC 124 outputs to the switch circuit 122.

[0034] As Figure 2 , the GND port of the control IC 124 is connected to the negative terminal 112 of the DC power supply.

[0035] Preferably, the CONT port of the control IC 124 is connected to the negative terminal 112 of the DC power supply via a second capacitor C2.

[0036] As Figure 2 , preferably, the two ends of the first capacitor C1 are also connected in parallel and reversely with a first diode D1. The negative terminal of the first diode D1 is connected to the power supply terminal VCC, and the positive terminal is connected between the first resistor R1 and the first capacitor C1.

[0037] Combined with Figure 2 , the switch circuit 122 includes a second resistor R2, a first voltage-regulating diode VR1, and an N-type MOS transistor Q1. The OUT port of the control IC 124 is connected to the G pole of the N-type MOS transistor Q1. The S pole of the N-type MOS transistor Q1 is connected to the negative terminal 112 of the DC power supply, and a second resistor R2 and a first voltage-regulating diode VR1 are also connected in parallel between the G pole of the N-type MOS transistor Q1 and the negative terminal 112 of the DC power supply. The D pole of the N-type MOS transistor Q1 outputs to the relay coil of the pre-stage switch relay KM.

[0038] Thus, combined with Figure 1 , 2 As shown in the example, when the positive terminal 111 and the negative terminal 112 of the DC power supply input a DC power supply, the anti-AC device 120 supplies power first for delay timing, and after a delay of 15 ms, the N-type MOS transistor Q1 of the control switch circuit is turned on. After the pre-stage switch relay KM1 is powered on, it effectively operates, and the controlled relays KM1 and KM2 are powered on and thus effectively operate.

[0039] When the positive terminal 111 and the negative terminal 112 of the DC power supply input an alternating current, when the AC input is +, the anti-AC device 120 starts power supply for delay timing, and when the AC input becomes - within a certain time (such as 10 ms), the anti-AC device 120 cuts off the power supply and stops timing. Therefore, the anti-AC device 120 will not time to the preset duration, such as 15 ms. Therefore, its switch circuit will not conduct, and the pre-stage switch relay KM will not operate all the time.

[0040] Thus, a relay circuit with input delay for anti-AC input is realized, which does not operate all the time during AC input, but reliably operates after delaying the preset duration during DC input, and has the advantage of not burning when the DC is reversely connected.

[0041] Combined Figure 1 , 2 As shown in the examples of Figure 1 and 2 , the feasible selection of each component is as follows:

[0042] The pre-stage switch relay KM1, the first relay KM1, and the second relay KM2 adopt the same model parameters. For example, the HF115F series relays can be used. In a 220VDC relay circuit, for example, the relays of the 110V (coil voltage rating) series in the HF115F series can be used;

[0043] The first diode D1: A fast-recovery diode can be used, especially a diode with a breakdown voltage above 100V. In this example, the 4148 type is used;

[0044] The protection diode D2: Use 1N series diodes with a reverse recovery time in the ms level and a high breakdown voltage. For example, use IN4005, 4006, 4007 series diodes;

[0045] The first voltage-regulator diode VD1 can use IN47 series voltage-regulator diodes. In this embodiment, the 1N4742A / 12V voltage-regulator diode is selected;

[0046] The voltage-dividing resistor RQ1: The resistance value is between 26K - 32K ohms. In the embodiment of the present invention, 28K ohms is used;

[0047] The starting resistor QP1: The resistance value is between 22K - 28K ohms. In the present invention, 28K ohms is selected;

[0048] The first capacitor C1: 1 - 1.2uF;

[0049] The second capacitor C2: 10 - 20nF;

[0050] The N-type MOS transistor Q1: Use a MOS transistor with a voltage of 600 - 800V / current of 0.4 - 1A. For example, the KIA1N60H type MOS transistor;

[0051] The first resistor R1: 10K - 50K ohms, which can be designed in combination with the first capacitor according to the design requirements of the delay time;

[0052] The second resistor R2: 12K ohms.

[0053] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the claims.

Claims

1. An anti - AC input intermediate relay circuit, characterized in that, Comprising: Positive terminal of the DC power supply (111); Negative terminal of the DC power supply (112); Pre-stage switch relay (KM); At least one controlled first relay (KM1), the coil of the first relay (KM1) is connected between the negative terminal of the DC power supply (112) and the output contact of the pre-stage switch relay (KM); AC resistance device (120), connected between the positive terminal of the DC power supply (111) and the negative terminal of the DC power supply (112), for controlling the operation of the pre-stage switch relay (KM) according to the input power supply type; Wherein, the other end of the switch circuit (122) is connected to the relay coil of the pre-stage switch relay (KM) through a series voltage-dividing resistor (RQ1), and the other end of the switch circuit (122) is connected to the normally-closed contact of the pre-stage switch relay (KM) and the positive terminal of the DC power supply (111) through a starting resistor (RP1); The AC resistance device (120) has a switch circuit (122), one end of the switch circuit (122) is connected to the negative terminal of the DC power supply (112), the other end is connected to the relay coil of the pre-stage switch relay (KM), and the other end of the relay coil of the pre-stage switch relay (KM) is connected to the positive terminal of the DC power supply (111); Wherein, the AC resistance device (120) controls the switch circuit (122) to turn off according to the detected AC input, and controls the switch circuit (122) to turn on according to the detected DC input; The AC resistance device (120) further includes a control circuit (121) for input delay, the control circuit (121) is connected to the switch circuit (122) for controlling the turn-off / turn-on of the switch circuit (122); The control circuit (121) for input delay includes a first resistor (R1), a first capacitor (C1) and a control IC (124), the first resistor (R1) and the first capacitor (C1) are connected in series between the negative terminal of the DC power supply (112) and the power supply terminal (VCC), the first resistor (R1) and the first capacitor (C1) form a delay time control circuit for controlling the delay duration T; the TRIG port and the THRES port of the control IC (124) are respectively connected between the first resistor (R1) and the first capacitor (C1), and the OUT port of the control IC (124) outputs to the switch circuit (122).

2. The anti - AC input intermediate relay circuit according to claim 1, wherein, A protection diode (D2) is further provided between the positive terminal of the DC power supply (111) and the relay coil of the pre-stage switch relay (KM), the positive electrode of the protection diode (D2) is connected to the positive terminal of the DC power supply (111), and its negative electrode is connected to the relay coil of the pre-stage switch relay (KM).

3. The anti - AC input intermediate relay circuit according to claim 1, characterized in that, The delay duration T is controlled to be 15 ms.

4. The anti - AC input intermediate relay circuit according to claim 1, wherein, A first diode (D1) is connected in parallel and reversely across the two ends of the first capacitor (C1), the negative terminal of the first diode (D1) is connected to the power supply terminal (VCC), and the positive terminal is connected between the first resistor (R1) and the first capacitor (C1).

5. The anti - AC input intermediate relay circuit according to claim 1, characterized in that, The switch circuit (122) includes a second resistor (R2), a first zener diode (VR1), and an N-type MOS transistor (Q1). The OUT port of the control IC (124) is connected to the G pole of the N-type MOS transistor (Q1). The S pole of the N-type MOS transistor (Q1) is connected to the negative terminal of the DC power supply (112). A second resistor (R2) and a first zener diode (VR1) are also connected in parallel between the G pole of the N-type MOS transistor (Q1) and the negative terminal of the DC power supply (112). The D pole of the N-type MOS transistor (Q1) outputs to the relay coil of the front-stage switch relay (KM).

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