High-voltage power supply type low-voltage contactor power supply circuit

Abstract

The utility model discloses a power supply circuit of a high-voltage power supply type low-voltage contactor. The power supply circuit comprises a rectification module, a first voltage stabilization module, a second voltage stabilization module, a voltage reduction power supply module, a current-limiting controllable power supply module, a first controllable low-voltage supply module, a second controllable low-voltage supply module, a control module and an inductor. The first input end of the rectifier module is connected to a mains supply line L, the second input end of the rectifier module is connected to a mains supply line N, and the first input end and the second input end of the rectifier module are connected to the high-voltage end and the low-voltage end of the first voltage stabilizing module respectively; the first output end of the rectifier module is connected to the input end of the step-down power supply module, and the output end of the step-down power supply module is connected to the input end of the current-limiting controllable power supply module and the power supply end of the control module. According to the high-voltage power supply type low-voltage contactor power supply circuit, the problem that the low-voltage contactor cannot output different voltages due to the fact that the commercial power conversion power supply circuit cannot output different voltages in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to a power supply circuit, in particular to a high-voltage power supply type low-voltage contactor power supply circuit. Background Art

[0002] The working principle of a contactor is similar to that of a relay. A contactor consists of a control coil and a controllable switch. Whether the control coil is energized or not is directly related to the opening and closing of the controllable switch. According to the operating voltage range of the contactor, it is divided into low-voltage contactors and high-voltage contactors. The voltage connected to the controllable switch in low-voltage contactors is less than 50V, while the voltage connected to the controllable switch in high-voltage contactors is greater than or equal to 50V.

[0003] Then when the mains is supplied, the mains is an AC 220V voltage, which is significantly higher than the operating voltage range of the low-voltage contactor. In order to adapt to the operating voltage range of the low-voltage contactor, a mains conversion power supply circuit is needed. In the prior art, the mains conversion power supply circuit includes: a rectifier bridge and a step-down voltage regulator chip, the first input end of the rectifier bridge is connected to the mains L line, the second input end of the rectifier bridge is connected to the mains N line, the first output end of the rectifier bridge is connected to the input end of the step-down voltage regulator chip, and the output end of the step-down voltage regulator chip is the output end of the entire mains conversion power supply circuit. Although the above-mentioned mains conversion power supply circuit can convert the mains into an operating voltage that the low-voltage contactor can accept, the mains conversion power supply circuit still has the disadvantage that: since the controllable switch of the low-voltage contactor needs to output different voltage values, and the mains conversion power supply circuit can only output one voltage value, the mains conversion power supply circuit cannot meet the needs. Utility Model Content

[0004] The utility model provides a high-voltage power supply type low-voltage contactor power supply circuit to solve the problem in the prior art that the mains power conversion power supply circuit cannot output different voltages, which causes the low-voltage contactor to be unable to output different voltages.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a high-voltage power supply type low-voltage contactor power supply circuit, comprising: a rectifier module, a first voltage stabilizing module, a second voltage stabilizing module, a step-down power supply module, a current-limiting controllable power supply module, a first controllable low-voltage supply module, a second controllable low-voltage supply module, a control module and an inductor; the first input end of the rectifier module is connected to the mains L line, the second input end of the rectifier module is connected to the mains N line, the first input end of the rectifier module and the second input end of the rectifier module are respectively connected to the high-voltage end and the low-voltage end of the first voltage stabilizing module; the high-voltage end of the second voltage stabilizing module is connected to the first output end of the rectifier module, and the low-voltage end of the second voltage stabilizing module is grounded; the first output end of the rectifier module is connected to the input end of the step-down power supply module, and the output end of the step-down power supply module is connected to the input end of the current-limiting controllable power supply module and the power supply end of the control module; a first side of the inductor is provided with a second A coil and a second coil, a third coil is provided on the second side of the inductor, the high-voltage end of the first coil is connected to the first output end of the rectifier module, and the high-voltage end of the second coil is connected to the input end of the current-limiting controllable power supply module; the high-voltage input end of the first controllable low-voltage supply module is connected to the first output end of the rectifier module, and the low-voltage output end of the first controllable low-voltage supply module is connected to the low-voltage end of the first coil; the high-voltage end of the second controllable low-voltage supply module is connected to the low-voltage end of the second coil, and the low-voltage end of the second controllable low-voltage supply module is grounded; the control end of the current-limiting controllable power supply module is connected to the low-voltage output end of the first controllable low-voltage supply module; the control end of the first controllable low-voltage supply module and the second controllable low-voltage supply module are respectively connected to the first output end and the second output end of the control module; the high-voltage end of the third coil is used to connect to one end of the controllable switch in the low-voltage contactor, and the low-voltage end of the third coil is grounded.

[0007] Preferably, the first voltage stabilizing module includes: capacitor C1 and capacitor C2, the positive electrode of capacitor C1 is the high voltage end of the first voltage stabilizing module, the negative electrode of capacitor C1 is connected to the positive electrode of capacitor C2, and the negative electrode of capacitor C2 is the low voltage end of the first voltage stabilizing module.

[0008] Preferably, the second voltage stabilizing module includes: capacitor C4 and capacitor C5, the positive electrode of capacitor C4 is the high voltage end of the first voltage stabilizing module, the positive electrode of capacitor C4 is connected to the positive electrode of capacitor C5, and the negative electrode of capacitor C4 and the negative electrode of capacitor C5 are connected to form the low voltage end of the first voltage stabilizing module.

[0009] Preferably, the high-voltage power supply type low-voltage contactor power supply circuit also includes: a current limiting and voltage regulating module, the high-voltage end of the third coil is connected to the input end of the current limiting and voltage regulating module, and the output end of the current limiting and voltage regulating module is used to connect to one end of the controllable switch in the low-voltage contactor.

[0010] Preferably, the current-limiting controllable power supply module includes: a current-limiting diode D2, a resistor R2 and a bidirectional thyristor U1, the anode of the current-limiting diode D2 is the input end of the current-limiting controllable power supply module, the cathode of the current-limiting diode D2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the input end of the bidirectional thyristor U1, the output end of the bidirectional thyristor U1 is the output end of the current-limiting controllable power supply module, and the control end of the bidirectional thyristor U1 is the control end of the current-limiting controllable power supply module.

[0011] Preferably, the step-down power supply module includes: a resistor R1, a capacitor C3 and a Zener diode D3, the first end of the resistor R1 is the input end of the step-down power supply module, the second end of the resistor R1 is connected to the positive electrode of the capacitor C3 and the cathode of the Zener diode D3, the negative electrode of the capacitor C3 and the anode of the Zener diode D3 are grounded, and the second end of the resistor R1 is the output end of the step-down power supply module.

[0012] Preferably, the first controllable low-voltage supply module includes: a resistor R3, a current-limiting diode D1, a MOS transistor Q1 and a resistor R4, the first end of the resistor R3 is the high-voltage input end of the first controllable low-voltage supply module, the second end of the resistor R3 is connected to the anode of the current-limiting diode D1, the cathode of the current-limiting diode D1 is connected to the drain of the MOS transistor Q1, the drain of the MOS transistor Q1 is the low-voltage output end of the first controllable low-voltage supply module, the source of the MOS transistor Q1 is grounded through the resistor R4, and the gate of the MOS transistor Q1 is the control end of the first controllable low-voltage supply module.

[0013] Preferably, the second controllable low-voltage supply module includes: a MOS transistor Q2 and a resistor R4, the drain of the MOS transistor Q2 is the high-voltage end of the second controllable low-voltage supply module, the source of the MOS transistor Q2 is connected to the first end of the resistor R4, the second end of the resistor R4 is grounded, the second end of the resistor R4 is the low-voltage end of the second controllable low-voltage supply module, and the gate of the MOS transistor Q2 is the control end of the second controllable low-voltage supply module.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In the present application, the following functions are implemented: first, when the MOS tube Q1 in the first controllable low-voltage supply module is turned on and the second controllable low-voltage supply module is not turned on, the first controllable low-voltage supply module provides a low voltage, so that the first coil on the first side of the inductor is energized and the second coil is not energized, so that the third coil generates current and voltage through the first coil after induction, so that the third coil outputs the first voltage value. Then, when the first controllable low-voltage supply module is turned on, the control end of the current-limiting controllable power supply module is connected to the voltage. At this time, the current-limiting controllable power supply module supplies power to the second coil, thereby realizing that the second coil is powered only after the first coil is connected. That is, the first controllable low-voltage supply module can also control the first coil to be de-energized, realizing that the first coil and the second coil are cut off when both the first coil and the second coil are not energized, thereby eliminating energy consumption and saving energy. At the same time, the control end of the current-limiting controllable power supply module is connected to the low-voltage output end of the first controllable low-voltage supply module, which can also realize that the second coil can only be energized after the first coil is energized, thereby controlling the inductor to have two voltage outputs, thereby avoiding the situation where only the second coil is connected. This situation is not required during use, so it is controlled that only the second coil is energized. Finally, a second controllable low-voltage supply module is designed to control the second coil to be selectively energized after the first coil is energized. When both the first coil and the second coil are energized, the high-voltage end of the third coil outputs a second voltage value.

[0016] The present invention will be understood by those skilled in the art through research and practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Circuit diagram of the power supply circuit for the high voltage power supply type low voltage contactor. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and functions of the present invention clearer and easier to understand, the present invention is further described below with reference to the accompanying drawings and specific embodiments:

[0019] like Figure 1As shown, the utility model discloses a high-voltage power supply type low-voltage contactor power supply circuit, including: a rectifier module BR1, a first voltage stabilizing module, a second voltage stabilizing module, a step-down power supply module, a current-limiting controllable power supply module, a first controllable low-voltage supply module, a second controllable low-voltage supply module, a control module and an inductor TR1; the first input end of the rectifier module BR1 is connected to the mains L line, the second input end of the rectifier module BR1 is connected to the mains N line, the first input end of the rectifier module BR1 and the second input end of the rectifier module BR1 are respectively connected to the high-voltage end and the low-voltage end of the first voltage stabilizing module; the high-voltage end of the second voltage stabilizing module is connected to the first output end of the rectifier module BR1, and the low-voltage end of the second voltage stabilizing module is grounded; the first output end of the rectifier module BR1 is connected to the input end of the step-down power supply module, and the output end VOUT1 of the step-down power supply module is connected to the input end of the current-limiting controllable power supply module and the power supply end of the control module; the inductor T A first coil and a second coil are provided on the first side of R1, and a third coil is provided on the second side of the inductor TR1. The high-voltage end of the first coil is connected to the first output end of the rectifier module BR1, and the high-voltage end of the second coil is connected to the input end of the current-limiting controllable power supply module; the high-voltage input end of the first controllable low-voltage supply module is connected to the first output end of the rectifier module BR1, and the low-voltage output end of the first controllable low-voltage supply module is connected to the low-voltage end of the first coil; the high-voltage end of the second controllable low-voltage supply module is connected to the low-voltage end of the second coil, and the low-voltage end of the second controllable low-voltage supply module is grounded; the control end of the current-limiting controllable power supply module is connected to the low-voltage output end of the first controllable low-voltage supply module; the control end CTR1 of the first controllable low-voltage supply module and the control end CTR2 of the second controllable low-voltage supply module are respectively connected to the first output end and the second output end of the control module; the high-voltage end of the third coil is used to connect to one end of the controllable switch in the low-voltage contactor, and the low-voltage end of the third coil is grounded.

[0020] The first voltage stabilization module includes capacitors C1 and C2. The positive terminal of capacitor C1 serves as the high-voltage terminal of the first voltage stabilization module, while the negative terminal of capacitor C1 is connected to the positive terminal of capacitor C2, which serves as the low-voltage terminal of the first voltage stabilization module. Capacitors C1 and C2 stabilize the mains L and N line inputs.

[0021] The second voltage-stabilizing module includes capacitors C4 and C5. The positive electrode of capacitor C4 serves as the high-voltage terminal of the first voltage-stabilizing module and is connected to the positive electrode of capacitor C5. The negative electrodes of capacitors C4 and C5 are connected to form the low-voltage terminal of the first voltage-stabilizing module. Capacitors C4 and C5 stabilize the voltage output by the first output terminal of rectifier module BR1.

[0022] The high-voltage power supply-type low-voltage contactor power supply circuit also includes a current-limiting and voltage-regulating module. The high-voltage end of the third coil is connected to the input end of the current-limiting and voltage-regulating module. The output end VOUT2 of the current-limiting and voltage-regulating module is connected to one end of a controllable switch in the low-voltage contactor. The current-limiting and voltage-regulating module includes a current-limiting diode D4 and a variable resistor VR1. The anode of the current-limiting diode D4 is connected to the input end of the current-limiting and voltage-regulating module, and the cathode of the current-limiting diode D4 is connected to one end of the variable resistor VR1. The other end of the variable resistor VR1 is connected to the output end of the current-limiting and voltage-regulating module.

[0023] After adjusting the output voltage of the high-voltage terminal of the third coil to the first or second voltage value, the current-limiting and voltage-regulating module can be adjusted to achieve fine-tuning of the output voltage. Since the first and second voltage values ​​output by the third coil differ significantly, using the current-limiting and voltage-regulating module's variable resistor to directly adjust the wide voltage span will be affected by temperature drift. The variable resistor's resistance value fluctuates significantly due to temperature drift, making it difficult to achieve the desired adjustment. Therefore, coarse adjustment is achieved by adjusting the power supply conditions of the first and second coils, that is, switching the output voltage value between the first and second voltage values, and then using variable resistor VR1 for fine-tuning to meet voltage supply requirements and reduce the impact of temperature drift.

[0024] The current-limiting controllable power supply module includes: a current-limiting diode D2, a resistor R2, and a bidirectional thyristor U1. The anode of the current-limiting diode D2 is the input end of the current-limiting controllable power supply module, the cathode of the current-limiting diode D2 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the input end of the bidirectional thyristor U1. The output end of the bidirectional thyristor U1 is the output end of the current-limiting controllable power supply module, and the control end of the bidirectional thyristor U1 is the control end of the current-limiting controllable power supply module. The current-limiting diode D2 limits the direction of current. The use of the bidirectional thyristor U1 realizes the on-off control of the circuit. It is realized that the bidirectional thyristor U1 is turned on only when there is voltage at the low-voltage output end of the first controllable low-voltage supply module.

[0025] The step-down power supply module includes a resistor R1, a capacitor C3, and a Zener diode D3. The first end of resistor R1 is the input end of the step-down power supply module. The second end of resistor R1 is connected to the positive electrode of capacitor C3 and the cathode of Zener diode D3. The negative electrode of capacitor C3 and the anode of Zener diode D3 are grounded. The second end of resistor R1 is the output end of the step-down power supply module. Capacitor C3 and Zener diode D3 provide voltage regulation, while resistor R1 provides voltage reduction.

[0026] The first controllable low-voltage supply module includes a resistor R3, a current-limiting diode D1, a MOS transistor Q1, and a resistor R4. The first end of resistor R3 serves as the high-voltage input terminal of the first controllable low-voltage supply module. The second end of resistor R3 is connected to the anode of current-limiting diode D1. The cathode of current-limiting diode D1 is connected to the drain of MOS transistor Q1. The drain of MOS transistor Q1 serves as the low-voltage output terminal of the first controllable low-voltage supply module. The source of MOS transistor Q1 is grounded via resistor R4. The gate of MOS transistor Q1 serves as the control terminal of the first controllable low-voltage supply module. MOS transistor Q1 functions as a controllable switch.

[0027] The second controllable low-voltage supply module includes a MOS transistor Q2 and a resistor R4. The drain of MOS transistor Q2 serves as the high-voltage terminal of the second controllable low-voltage supply module. The source of MOS transistor Q2 is connected to the first terminal of resistor R4. The second terminal of resistor R4 is grounded. The second terminal of resistor R4 serves as the low-voltage terminal of the second controllable low-voltage supply module. The gate of MOS transistor Q2 serves as the control terminal of the second controllable low-voltage supply module. MOS transistor Q2 functions as a controllable switch.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A high voltage power supply type low voltage contactor power supply circuit, characterized in that: include: Rectifier module, first voltage stabilizing module, second voltage stabilizing module, step-down power supply module, current limiting controllable power supply module, first controllable low-voltage supply module, second controllable low-voltage supply module, control module and inductor; The first input end of the rectifier module is connected to the mains L line, the second input end of the rectifier module is connected to the mains N line, and the first input end of the rectifier module and the second input end of the rectifier module are respectively connected to the high voltage end and the low voltage end of the first voltage stabilizing module; The high voltage end of the second voltage stabilizing module is connected to the first output end of the rectifier module, and the low voltage end of the second voltage stabilizing module is grounded; The first output end of the rectifier module is connected to the input end of the step-down power supply module, and the output end of the step-down power supply module is connected to the input end of the current-limiting controllable power supply module and the power supply end of the control module; A first coil and a second coil are provided on the first side of the inductor, and a third coil is provided on the second side of the inductor. The high-voltage end of the first coil is connected to the first output end of the rectifier module, and the high-voltage end of the second coil is connected to the input end of the current-limiting controllable power supply module; The high-voltage input terminal of the first controllable low-voltage supply module is connected to the first output terminal of the rectifier module, and the low-voltage output terminal of the first controllable low-voltage supply module is connected to the low-voltage terminal of the first coil; The high voltage end of the second controllable low voltage supply module is connected to the low voltage end of the second coil, and the low voltage end of the second controllable low voltage supply module is grounded; The control end of the current-limiting controllable power supply module is connected to the low-voltage output end of the first controllable low-voltage supply module; The control end of the first controllable low-voltage supply module and the second controllable low-voltage supply module are respectively connected to the first output end and the second output end of the control module; the high-voltage end of the third coil is used to connect to one end of the controllable switch in the low-voltage contactor, and the low-voltage end of the third coil is grounded.

2. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 1, characterized in that: The first voltage stabilizing module includes: a capacitor C1 and a capacitor C2. The positive electrode of the capacitor C1 is the high voltage end of the first voltage stabilizing module. The negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C2. The negative electrode of the capacitor C2 is the low voltage end of the first voltage stabilizing module.

3. The high voltage power supply type low voltage contactor power supply circuit according to claim 1, characterized in that: The second voltage stabilizing module includes: capacitor C4 and capacitor C5. The positive electrode of capacitor C4 is the high voltage end of the first voltage stabilizing module. The positive electrode of capacitor C4 is connected to the positive electrode of capacitor C5. The negative electrode of capacitor C4 and the negative electrode of capacitor C5 are connected to form the low voltage end of the first voltage stabilizing module.

4. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 1, characterized in that: Also includes: The current limiting and voltage regulating module, the high voltage end of the third coil is connected to the input end of the current limiting and voltage regulating module, and the output end of the current limiting and voltage regulating module is used to connect to one end of the controllable switch in the low voltage contactor.

5. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 4, characterized in that: The current-limiting controllable power supply module includes: a current-limiting diode D2, a resistor R2 and a bidirectional thyristor U1. The anode of the current-limiting diode D2 is the input end of the current-limiting controllable power supply module, the cathode of the current-limiting diode D2 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the input end of the bidirectional thyristor U1. The output end of the bidirectional thyristor U1 is the output end of the current-limiting controllable power supply module, and the control end of the bidirectional thyristor U1 is the control end of the current-limiting controllable power supply module.

6. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 5, characterized in that: The step-down power supply module includes: a resistor R1, a capacitor C3 and a Zener diode D3. The first end of the resistor R1 is the input end of the step-down power supply module, the second end of the resistor R1 is connected to the positive electrode of the capacitor C3 and the cathode of the Zener diode D3, the negative electrode of the capacitor C3 and the anode of the Zener diode D3 are grounded, and the second end of the resistor R1 is the output end of the step-down power supply module.

7. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 1, characterized in that: The first controllable low-voltage supply module includes: a resistor R3, a current-limiting diode D1, a MOS transistor Q1, and a resistor R4. The first end of the resistor R3 is the high-voltage input end of the first controllable low-voltage supply module, the second end of the resistor R3 is connected to the anode of the current-limiting diode D1, the cathode of the current-limiting diode D1 is connected to the drain of the MOS transistor Q1, the drain of the MOS transistor Q1 is the low-voltage output end of the first controllable low-voltage supply module, the source of the MOS transistor Q1 is grounded through the resistor R4, and the gate of the MOS transistor Q1 is the control end of the first controllable low-voltage supply module.

8. The high-voltage power supply type low-voltage contactor power supply circuit according to claim 1, characterized in that: The second controllable low-voltage supply module includes: a MOS transistor Q2 and a resistor R4. The drain of the MOS transistor Q2 is the high-voltage end of the second controllable low-voltage supply module. The source of the MOS transistor Q2 is connected to the first end of the resistor R4. The second end of the resistor R4 is grounded. The second end of the resistor R4 is the low-voltage end of the second controllable low-voltage supply module. The gate of the MOS transistor Q2 is the control end of the second controllable low-voltage supply module.

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