摘要 |
<p>An electronic temperature control for a cordless ironing apparatus. The temperature of the sole plate of the iron is sensed by a thermistor embedded therein; the thermistor is part of an astable multivibrator circuit, and any change in temperature of the sole plate causes a change in resistance of the thermistor, and a corresponding change in frequency at the output of the multivibrator. This output drives an infrared LED, and the light emitted by the LED in the iron is sensed by a phototransistor in the base, which relays the sensed temperature information to a microprocessor therein which controls the current applied to the heating element accordingly, to maintain the desired temperature of the sole plate.</p> |