Quick discharge circuit for shutdown of energy storage capacitor

Abstract

The utility model relates to the technical field of energy storage capacitor protection, in particular to an energy storage capacitor shutdown rapid discharge circuit. An output positive electrode of an optocoupler U10 is connected with a positive electrode of a power supply through a resistor R38 and a resistor R52, an output negative electrode of the optocoupler U10 is connected with the power supply ground, a voltage-regulator tube D10 and a capacitor C44 are connected in parallel between the output positive electrode and the output negative electrode of the optocoupler U10, and a positive electrode of the voltage-regulator tube D10 is connected with the ground; the execution circuit comprises an MOS tube Q2, a grid electrode of the MOS tube Q2 is connected with an output positive electrode of the optocoupler U10 through a resistor R53, a source electrode of the MOS tube Q2 is connected with the power supply ground, and a drain electrode of the MOS tube Q2 is connected with a positive electrode of the power supply through a discharge resistor; the energy storage capacitor is connected between the power supply anode and the power supply ground. In a normal working state, the discharge circuit is in a high-impedance mode and is activated only when rapid discharge is needed, so that power consumption at ordinary times is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage capacitor protection, in particular to a shutdown fast discharge circuit of an energy storage capacitor. Background Art

[0002] In many electronic devices, energy storage capacitors are used to maintain power stability, filter or store energy. When the device is turned off, if the charge in these capacitors is not released in time, they may remain in a high voltage state for a period of time, which not only prolongs the power-off process of the device, but also may pose a safety hazard to operators and increase unnecessary standby power consumption. Traditional discharge methods usually rely on natural discharge of parallel resistors, but this results in slow discharge and high energy consumption.

[0003] The Chinese utility model patent "A surge current suppression circuit and system for rapid power on and off" (application number CN202311761758.2) can effectively suppress the surge current caused by the energy storage filter capacitor when starting up, and quickly release the energy in the control circuit after shutting down. However, in some cases, abnormal power outages may occur and the discharge cannot occur. Summary of the invention

[0004] In view of the shortcomings of the prior art, the utility model proposes a storage capacitor shutdown fast discharge circuit. The utility model identifies the external 220V voltage power supply situation and ensures that the storage capacitor can discharge quickly when the external power supply is cut off.

[0005] The technical scheme of the utility model is: a storage capacitor shutdown fast discharge circuit, including a signal acquisition circuit, a driving isolation circuit and an execution circuit, the signal acquisition circuit acquires input AC signals, and the driving isolation circuit drives the execution circuit according to the acquired signals; it is characterized in that: the signal acquisition circuit includes a socket J5, and the socket J5 is respectively connected with AC 220v wires, one wire is connected in series with a capacitor C27, a resistor R39 and a resistor R40 and then connected to the input end of the rectifier bridge chip D9, and the other wire is connected in series with a capacitor C40, a resistor R55 and a resistor R56 and then connected to the other input end of the rectifier bridge chip D9, and the output signal of the rectifier bridge chip D9 is connected in parallel with the resistor R54 and the capacitor C41; the driving isolation circuit input is the output signal of the rectifier bridge chip D9 The output signal of the rectifier bridge chip D9 is connected in parallel with the resistor R54 and the capacitor C41. The output signal of the rectifier bridge chip D9 is connected to the input of the optocoupler U10 after passing through the resistor R42. The positive electrode of the output of the optocoupler U10 is connected to the positive electrode of the power supply through the resistor R38 and the resistor R52. The negative electrode of the output of the optocoupler U10 is connected to the power ground. The positive and negative electrodes of the output of the optocoupler U10 are connected in parallel with the voltage regulator tube D10 and the capacitor C44. The positive electrode of the voltage regulator tube D10 is connected to the ground. The execution circuit includes a MOS tube Q2. The gate of the MOS tube Q2 is connected to the positive electrode of the output of the optocoupler U10 through the resistor R53. The source of the MOS tube Q2 is connected to the power ground. The drain of the MOS tube Q2 is connected to the positive electrode of the power supply through the discharge resistor. The energy storage capacitor is connected between the positive electrode of the power supply and the power ground.

[0006] According to the energy storage capacitor shutdown fast discharge circuit as described above, it is characterized in that the rectifier bridge chip D9 is an abs10 rectifier bridge.

[0007] According to the energy storage capacitor shutdown fast discharge circuit as described above, the feature is that the discharge resistor is composed of multiple resistors connected in parallel.

[0008] According to the energy storage capacitor shutdown fast discharge circuit as described above, it is characterized in that: the discharge resistor is a resistor R35, a resistor R36, and a resistor R37 connected in parallel to form a discharge resistor, and the resistors R35, R36, and R37 are all 51 ohm resistors.

[0009] According to the energy storage capacitor shutdown fast discharge circuit as described above, the feature is that the energy storage capacitor is composed of a plurality of energy storage capacitors connected in parallel.

[0010] According to the energy storage capacitor shutdown fast discharge circuit as described above, the characteristic is that the energy storage capacitor is four 1000μF energy storage capacitors with a withstand voltage level of 50V connected in parallel.

[0011] The beneficial effect of the utility model is that under normal working conditions, the discharge circuit is in a high impedance mode and is activated only when rapid discharge is required, thereby reducing normal power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the circuit structure of the utility model. DETAILED DESCRIPTION

[0013] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0014] like Figure 1 The utility model discloses a fast discharge circuit for energy storage capacitor shutdown, which includes a signal acquisition circuit, a driving isolation circuit and an execution circuit. The signal acquisition circuit acquires the input AC signal, and the driving isolation circuit drives the execution circuit according to the acquired signal. When the input AC signal is normal, the driving isolation circuit clamps the execution circuit and stops it from working; when the input AC signal is abnormal, the driving isolation circuit drives the execution circuit, so that the charge of the energy storage capacitor is connected to the parallel resistor, forming a loop for fast discharge.

[0015] like Figure 1 As shown, the signal acquisition circuit of the utility model includes a socket J5, and the socket J5 is respectively connected with the wires of AC 220V. One wire is connected in series with capacitor C27, resistor R39 and resistor R40 and then connected to the input end of the rectifier bridge chip D9. Another wire is connected in series with capacitor C40, resistor R55 and resistor R56 and then connected to the other input end of the rectifier bridge chip D9. The output signal of the rectifier bridge chip D9 is connected in parallel with resistor R54 and capacitor C41. When the AC 220V input is normal, the V+ and V- of the rectifier bridge chip D9 are high potential; after the AC 220V is powered off, the V+ and V- of the rectifier bridge chip D9 are low potential, so that the utility model can identify whether the current input is normal. The rectifier bridge chip D9 of the utility model can be an abs10 rectifier bridge.

[0016] like Figure 1 As shown, the input of the push isolation circuit of the utility model is the output signal of the rectifier bridge chip D9, the resistor R54 and the capacitor C41 are connected in parallel to the output signal of the rectifier bridge chip D9, and the output signal of the rectifier bridge chip D9 is connected to the input of the optocoupler U10 after passing through the resistor R42. The positive electrode of the output of the optocoupler U10 is connected to the positive electrode of the power supply through the resistor R38 and the resistor R52, and the negative electrode of the output of the optocoupler U10 is connected to the power ground. The positive and negative electrodes of the output of the optocoupler U10 are connected in parallel with the voltage regulator tube D10 and the capacitor C44, and the positive electrode of the voltage regulator tube D10 is connected to the ground. The push isolation circuit of the utility model stabilizes the input collected signal within a certain range as the input of the execution circuit.

[0017] The execution circuit of the utility model includes a MOS tube Q2, the gate of the MOS tube Q2 is connected to the positive electrode of the output of the optical coupler U10 through a resistor R53, the source of the MOS tube Q2 is connected to the power ground, and the drain of the MOS tube Q2 is connected to the positive electrode of the power supply through a discharge resistor. The energy storage capacitor is connected between the positive electrode of the power supply and the power ground. The discharge resistor of the utility model can be composed of multiple resistors connected in parallel, such as Figure 1 As shown, this embodiment uses resistors R35, R36, and R37 in parallel to form a discharge resistor, and resistors R35, R36, and R37 are all 51 ohm resistors. The energy storage capacitor of the utility model can also be a plurality of energy storage capacitors connected in parallel between the positive pole of the power supply and the power ground, such as Figure 1 In the figure, four 1000μF energy storage capacitors with a withstand voltage level of 50V are connected in parallel. The energy storage capacitor of the utility model can also be a plurality of energy storage capacitors connected in parallel between the positive pole of the power supply and the power ground, such as Figure 1 In the figure, four 1000μF energy storage capacitors with a withstand voltage level of 50V are connected in parallel. Even when the 50V DC power supply is cut off, if there is high voltage in the energy storage capacitor, the MOS tube Q2 is in the on state, thereby ensuring that the energy storage capacitor can be discharged to a lower level even when the DC power supply is cut off, thereby more effectively protecting the circuit.

[0018] This circuit can quickly discharge the charge on the energy storage capacitor group when the AC input is turned off. When the AC input 220V power supply is normal, the optocoupler U10 is turned on, the gate of the MOS tube Q2 is low, the MOS tube Q2 is cut off, and the discharge circuit does not work. When the 220V power supply is turned off, the optocoupler 10 is not turned on, the gate voltage of the MOS tube Q2 is equal to the voltage of the voltage regulator tube D10, and when the voltage selected by the voltage regulator tube D10 is higher than the gate conduction voltage, the MOS tube is turned on, and the charge of the energy storage capacitor is quickly discharged through the parallel resistor.

Claims

1. A storage capacitor shutdown fast discharge circuit, comprising a signal acquisition circuit, a driving isolation circuit and an execution circuit, wherein the signal acquisition circuit acquires an input AC signal, and the driving isolation circuit drives the execution circuit according to the acquired signal; characterized in that: The signal acquisition circuit includes a socket J5, and the socket J5 is connected to the AC 220V wires respectively. One wire is connected in series with the capacitor C27, the resistor R39 and the resistor R40 and then connected to the input end of the rectifier bridge chip D9. The other wire is connected in series with the capacitor C40, the resistor R55 and the resistor R56 and then connected to the other input end of the rectifier bridge chip D9. The output signal of the rectifier bridge chip D9 is connected in parallel with the resistor R54 and the capacitor C41; the input of the push isolation circuit is the output signal of the rectifier bridge chip D9, the resistor R54 and the capacitor C41 are connected in parallel to the output signal of the rectifier bridge chip D9, and the output signal of the rectifier bridge chip D9 is connected to the output signal of the rectifier bridge chip D9 through the resistor R 42 is connected to the input of the optocoupler U10; the positive electrode of the optocoupler U10 output is connected to the positive electrode of the power supply through the resistor R38 and the resistor R52, the negative electrode of the optocoupler U10 output is connected to the power ground, a voltage regulator D10 and a capacitor C44 are connected in parallel between the positive and negative electrodes of the optocoupler U10 output, and the positive electrode of the voltage regulator D10 is connected to the ground; the execution circuit includes a MOS tube Q2, the gate of the MOS tube Q2 is connected to the positive electrode of the optocoupler U10 output through the resistor R53, the source of the MOS tube Q2 is connected to the power ground, and the drain of the MOS tube Q2 is connected to the positive electrode of the power supply through the discharge resistor; the energy storage capacitor is connected between the positive electrode of the power supply and the power ground.

2. The energy storage capacitor shutdown fast discharge circuit according to claim 1, characterized in that: The rectifier bridge chip D9 is an abs10 rectifier bridge.

3. A shutdown fast discharge circuit for energy storage capacitors according to claim 1 or 2, characterized in that: The discharge resistor is composed of multiple resistors connected in parallel.

4. A shutdown fast discharge circuit for energy storage capacitors according to claim 1 or 2, characterized in that: The discharge resistor is formed by connecting resistor R35, resistor R36 and resistor R37 in parallel. The resistors R35, R36 and R37 are all 51 ohm resistors.

5. A shutdown fast discharge circuit for energy storage capacitors according to claim 1 or 2, characterized in that: The energy storage capacitor is composed of multiple energy storage capacitors connected in parallel.

6. A shutdown fast discharge circuit for energy storage capacitors according to claim 1 or 2, characterized in that: The energy storage capacitor is 4 1000μF energy storage capacitors with a withstand voltage level of 50V connected in parallel.

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