| 摘要 |
A hot air-blower off-state residual heat preventive control circuit comprises a power voltage stabilizer circuit, a power frequency detection circuit, a microprocessor, a switching control circuit, a LED display circuit, an amplifier circuit, and a rectifier and noise control circuit, wherein when the user turns on the hot air-blower, the microprocessor drives a first bi-directional switch and a second bi-directional switch to turn on a main thermal resistor and a fan motor respectively; when the user turns off the hot air-blower, the microprocessor drives the first bi-directional switch to turn off the main thermal resistor and keeps the second bi-directional switch turning on the fan motor for a predetermined length of time, and then drives the second bi-directional switch to turn off the fan motor a predetermined length of time after off-state of the main thermal resistor.
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