Patent ID: 9715982
Date: 2017-07-25
CPC Classifications: G08B,H01H

Claim:
1. An alarm circuit for electronic device comprising: a detection circuit configured to detect a working status of an electronic device and output a control signal of a first voltage level when the detection circuit determines the presence of smoke in the electronic device; a signal conversion circuit configured to receive the control signal of the first voltage level and convert the control signal of the first voltage level to an alarm signal of a first voltage level; an alarm control circuit configured to receive the alarm signal of the first voltage level and transmit an alarm, wherein the detection circuit comprises a diode, a first switch, and a first resistor; the diode comprises an anode and a cathode; the first switch comprises a first terminal and a second terminal, the anode of the diode is configured to receive a direct current (DC) voltage; the cathode of the diode is electrically coupled to the first terminal of the first switch, the second terminal of the first switch is grounded via the first resistor; and a connection point between the second terminal of the first switch and the first resistor is configured to output the control signal; and wherein the signal conversion circuit comprises a second switch, a second resistor, and a third resistor; the second switch comprises a first terminal, a second terminal, and a third terminal; the first terminal of the second switch is electrically coupled to the connection point between the second terminal of the first switch and the first resistor and is configured to receive the control signal; the second terminal of the second switch is grounded; the third terminal of the second switch is configured to receive the DC voltage via the second resistor and the third resistor connected in series; and a connection point between the second resistor and the third resistor is configured to output the alarm signal.