Power supply system and power device for power failure protection

Abstract

The application relates to the field of electronic technology, in particular to a power-off protection power supply system and a power device, which comprises a power-off detection circuit, a super capacitor circuit, an under-voltage lock discharge circuit and a voltage stabilizing circuit. The power-off detection circuit is used for detecting a power supply voltage, generating a discharge control signal, a power-off enable signal and a power-off notification signal. The super capacitor circuit is used for receiving a charging voltage to generate a capacitor voltage. The under-voltage lock discharge circuit is used for receiving the discharge control signal and the capacitor voltage, generating a continuation supply voltage according to the capacitor voltage, or releasing residual electricity of the super capacitor circuit according to the discharge control signal. The voltage stabilizing circuit is used for receiving the power-off enable signal and the continuation supply voltage, generating a second supply voltage according to the power-off enable signal and the continuation supply voltage. The application actively discharges the super capacitor circuit after power supply through the under-voltage lock discharge circuit, releases the residual electricity of the super capacitor circuit, and prevents the residual electricity from affecting the normal start of the power consumption system.

Claims

1. A power failure protection power supply system, characterized in that, include: The power failure detection circuit (1) is used to receive and detect the power supply voltage (V1) and generate a discharge control signal (S1), a power failure enable signal (S2) and a power failure notification signal (S3) at the output terminal. A supercapacitor circuit (2) is used to receive the charging voltage (V2) and generate a capacitor voltage (V3) at the output terminal; The undervoltage lockout discharge circuit (3) is connected to the power failure detection circuit (1) and the supercapacitor circuit (2), and is used to receive the discharge control signal (S1) and the capacitor voltage (V3), generate the follow-up voltage (V4) according to the capacitor voltage (V3), or release the residual power of the supercapacitor circuit (2) according to the discharge control signal (S1). The voltage regulator circuit (4) is connected to the undervoltage lockout discharge circuit (3) and the power failure detection circuit (1), and is used to receive the power failure enable signal (S2) and the power supply voltage (V4), and generate a second power supply voltage (V6) according to the power failure enable signal (S2) and the power supply voltage (V4).

2. The power failure protection power supply system according to claim 1, characterized in that, The power failure detection circuit (1) includes, The voltage detection unit (11) is used to receive the power supply voltage (V1) and generate a voltage detection signal at the output terminal based on the power supply voltage (V1); The first optocoupler (U1) is connected to the output terminal of the voltage detection unit (11) via a first resistor (R1) on its input side. It is used to receive the voltage detection signal and generate the discharge control signal (S1) on the output side based on the voltage detection signal. The second optocoupler (U2) is connected to the output terminal of the voltage detection unit (11) via a second resistor (R2) on its input side. It is used to receive the voltage detection signal and generate the power-down enable signal (S2) on the output side based on the voltage detection signal. The third optocoupler (U3) is connected to the output terminal of the voltage detection unit (11) via a third resistor (R3) on the input side. It is used to receive the voltage detection signal and generate the power-down notification signal (S3) on the output side based on the voltage detection signal.

3. The power failure protection power supply system according to claim 2, characterized in that, The voltage detection unit (11) includes: A first voltage regulator (U4) has its cathode used to receive the power supply voltage (V1) through a fourth resistor (R4), its reference terminal used to receive a first reference voltage, and its anode grounded. The first reference voltage is generated by voltage division using a fifth resistor (R5) and a sixth resistor (R6). The first terminal of the fifth resistor (R5) is used to receive the power supply voltage (V1), the second terminal of the fifth resistor (R5) is connected to the reference terminal of the first voltage regulator (U4), the first terminal of the sixth resistor (R6) is connected to the second terminal of the fifth resistor (R5), and the second terminal of the sixth resistor (R6) is grounded. The first MOSFET (Q1) has its source used to receive the power supply voltage (V1), its gate connected to the cathode of the first voltage regulator (U4) via a seventh resistor (R7), and its drain is the output terminal of the voltage detection unit (11) for outputting the voltage detection signal.

4. The power failure protection power supply system according to claim 2, characterized in that, When the power supply voltage (V1) is less than the voltage threshold, the discharge control signal (S1), the power-down enable signal (S2), and the power-down notification signal (S3) are in a high-impedance state; when the power supply voltage (V1) is greater than or equal to the voltage threshold, the discharge control signal (S1), the power-down enable signal (S2), and the power-down notification signal (S3) are in a low-impedance state.

5. The power failure protection power supply system according to claim 3, characterized in that, The voltage detection unit (11) further includes a first capacitor (C1) and a nineteenth resistor (R19). The first end of the first capacitor (C1) is connected to the reference terminal of the first voltage regulator (U4), and the second end of the first capacitor (C1) is grounded. The first end of the nineteenth resistor (R19) is connected to the drain of the first MOS transistor (Q1), and the second end of the nineteenth resistor (R19) is grounded.

6. The power failure protection power supply system according to claim 2, characterized in that, The undervoltage lockout discharge circuit (3) includes: The second voltage regulator (U5) has its cathode used to receive the capacitor voltage (V3) through the eighth resistor (R8), its reference terminal used to receive a second reference voltage, and its anode grounded. The second reference voltage is generated by voltage division using the ninth resistor (R9) and the tenth resistor (R10). The first terminal of the ninth resistor (R9) is used to receive the capacitor voltage (V3), the second terminal of the ninth resistor (R9) is connected to the reference terminal of the second voltage regulator (U5), the first terminal of the tenth resistor (R10) is connected to the second terminal of the ninth resistor (R9), and the second terminal of the tenth resistor (R10) is grounded. The second MOSFET (Q2) has its source used to receive the capacitor voltage (V3), its gate connected to the cathode of the second regulator (U5) via the eleventh resistor (R11), and its drain is the output of the undervoltage lockout discharge circuit (3) used to generate the follow-up voltage (V4).

7. The power failure protection power supply system according to claim 6, characterized in that, The undervoltage lockout discharge circuit (3) also includes: The transistor (Q3) has its emitter connected to the first output terminal of the first optocoupler (U1) via the twelfth resistor (R12) and to the output terminal of the supercapacitor circuit (2) to receive the capacitor voltage (V3). The base of the transistor (Q3) is connected to the second output terminal of the first optocoupler (U1) and the drain of the second MOS transistor (Q2), and is grounded via the thirteenth resistor (R13). The discharge unit (31) has its first end connected to the collector of the transistor (Q3) and its second end grounded.

8. The power failure protection power supply system according to claim 6, characterized in that, The undervoltage lockout discharge circuit (3) also includes a fourteenth resistor (R14), the first end of which is connected to the output terminal of the supercapacitor circuit (2) to receive the capacitor voltage (V3), and the second end of which is grounded.

9. The power failure protection power supply system according to claim 6, characterized in that, The undervoltage lockout discharge circuit (3) further includes a second capacitor (C2), the first end of which is connected to the reference terminal of the second voltage regulator (U5), and the second end of which is grounded.

10. The power failure protection power supply system according to claim 4, characterized in that, The voltage threshold is 9V to 36V.

11. The power failure protection power supply system according to claim 4, characterized in that, It also includes a step-down circuit (5) connected to the supercapacitor circuit (2). The step-down circuit (5) is used to receive the power supply voltage (V1) and generate a first power supply voltage (V5) and the charging voltage (V2) at the output terminal.

12. An electrical device, characterized in that, The system includes an electrical system (6) and a power failure protection power supply system as described in any one of claims 1-11, wherein the power failure protection power supply system is connected to the electrical system (6), the electrical system (6) is used to receive a power failure notification signal (S3), and when the power supply voltage (V1) is less than a voltage threshold, the power failure protection power supply system is used to output a second power supply voltage (V6) to the electrical system (6) to supply power, and when the power supply voltage (V1) is greater than or equal to the voltage threshold, the power failure protection power supply system is used to output a first power supply voltage (V5) to the electrical system (6) to supply power.

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