Patent ID: 9166444
Filing Date: 2015-10-20
Classification: H02H,H02J,H02M

Abstract:
1. A control circuit comprising: an input terminal for receiving an input voltage; an energy accumulator for storing electric energy from the input terminal and supplying power to an electrical load; a first switching unit arranged between the input terminal and the energy accumulator; a converter for converting an AC voltage to a DC voltage to be supplied to the input terminal; a low-voltage generating unit arranged between the energy accumulator and the electrical load for generating a lower DC voltage from an output DC voltage of the energy accumulator; and an over-voltage protection unit for lowering the voltage at the input terminal when the voltage at an output terminal of the energy accumulator exceeds a predetermined threshold value, the over-voltage protecting unit comprising: wherein if the output voltage of the energy accumulator exceeds the threshold value, the second switching unit is made conductive and the voltage at the input terminal is reduced; as a result, the output voltage of the energy accumulator is higher than the voltage at the input terminal, the first switching unit electrically disconnects the input terminal from the energy accumulator, and the energy accumulator supplies power to the electrical load from the stored energy; with the stored energy of the energy accumulator being consumed, the output voltage of the energy accumulator decreases; when the detecting unit detects the output voltage of the energy accumulator is lower than the threshold value, the second switching unit is opened; as a result, the voltage at the input terminal is higher than the output voltage of the energy accumulator, the first switching unit electrically connects the input terminal to the energy accumulator, and the energy accumulator is charged by the current from the input terminal and supplies power to the electrical load, and wherein the energy accumulator comprises a capacitor and the low-voltage generating unit comprises a resistor and a Zener diode; one end of the resistor is electrically connected with the positive terminal of the capacitor, the other end is electrically connected with the cathode of the Zener diode, and the anode of the Zener diode and the negative terminal of the capacitor are electrically connected with ground.