| 摘要 |
PURPOSE: A reset circuit of a main controller is provided to protect the main controller by sensing that a standby voltage provided to the main controller is abnormally dropped and automatically resetting the main controller. CONSTITUTION: A reset pulse generating unit(300) generates a reset pulse when a standby voltage outputted from a power supply unit to a microcomputer(100) is dropped down a standard level and outputs the generated reset pulse to the microcomputer(100). Resistors(R1,R2) are connected with a reset port(P1) and a ground port of the microcomputer(100) for dividing the standby voltage provided to the reset port(P1). The first transistor(Q1) is connected with a connection point of resistors(R1,R2) and a secondary voltage input port at its base and emitter, and is turned on/off by a base voltage. The second transistor(Q2) is connected with a collector of the first transistor(Q1) and the reset port(P1) at its base and collector, and grounds the standby voltage when performing a switching operation of the first transistor(Q1).
|
