| 摘要 |
<p>PURPOSE:To raise the accuracy for controlling a temperature, and also to exactly confirm a state that a heating operation mode has been set, by controlling a semiconductor switch by a pulse signal from a timing circuit, in a temperature control device used for an electric ''Kotatsu'' (a foot warmer with a quilt over it). CONSTITUTION:A temperature control signal A is supplied to a temperature controlling circuit 14, the circuit 14 controls a semiconductor switching circuit 15, and controls lighting of a lamp 16 operating as a heater. A current for a temperature in a ''Kotatsu'' by this lamp 16 is fed back B to the circuit 14, is compared with a signal A, a lighting time of the lamp 16 is controlled by the circuit 15, and the inside of the ''Kotatsu'' is held within a specific temperature range. In this state, a timing pulse signal is generated at specific time internals from a timing circuit 17, and is supplied to the circuit 15 through an adding circuit 18. In this way, the lighting operation is confirmed during the period of a half-wave corresponding to a timing pulse in the lamp 16.</p> |
