Protection circuit

A protection circuit, applied in an inductive boost converter, the inductive boost converter comprising a transmission circuit and a charging circuit, wherein the protection circuit comprises a detection circuit and a control circuit, an input terminal of the detection circuit and an output terminal of the transmission circuit are connected, a first output terminal of the detection circuit and an input terminal of the charging circuit are connected, a second output terminal of the detection circuit and an input terminal of the control circuit are connected;

• the detection circuit detects whether an input current from the transmission circuit is a short-circuit current, if the circuit is shorted, the detection result will be sent to the control circuit, the control circuit cuts the connection of the charging circuit and ground, which prevents charges stored in the charging circuit from flowing backward into the input terminal of the inductive boost converter,
• wherein the transmission circuit comprises an inductor and a diode, one end of the inductor of the transmission circuit is connected to an input terminal of the inductive boost converter, the other end of the inductor is connected to a cathode of the diode;
• the charging circuit comprises at least one capacitor, each of the capacitors in the at least one capacitor are parallel connected with each other, a parallel connection output terminal of the charging circuit is the output terminal of the inductive boost converter;
• the transmission circuit transmits charges to the charging circuit, the charging circuit stores the charges from the transmission circuit and generates an output voltage, the output voltage value is higher than the input voltage value of the input terminal;
• wherein the detection circuit comprises an optical coupler, the optical coupler comprises a light emitting diode and a triode, a cathode of the light emitting diode and an anode of the diode of the transmission circuit are connected, the anode of the light emitting diode and the input terminal of the charging circuit are connected;
• the light emitting diode detects whether an input current from the transmission circuit is the short-circuit current, if the circuit is shorted, the light emitting diode will sent optical signals for triggering the triode to generate photocurrents, resulting in turning on the triode.