| 摘要 |
The voltage of the power plug (PL) is applied to the relay switch (RL11) and a transformer (T) of the power block (2) through a resistor (R11) and diodes (D11,D12) connected in serial to a contact switch (TSW), and resistors (R12,R13) when the contact switch is cut off. An intermediate point of resistor (R12,R13) is connected to the contact switch through a diode (D13) and to a LED (DD) of a photo coupler (PC) generating a pulse signal. The collector of the light receiving transistor (PTR) of the photo coupler receiving the pulse signal is connected to the input terminal (IN) of the microprocessor (1) through a resistor (R14), and also to a power block (2) and the power input terminal (VIN) of the microprocessor.
|
