Phototransistor relay electronic temperature control for cordless irons
US4827104A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1986 |
| Grant date | May 2, 1989 |
| Priority date | — |
| Expiry date | Oct 16, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/2454
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.