| 摘要 |
PURPOSE:To reduce the consumption of a pilot cell by a method wherein a power-on indication at the lower surface side of the top plate among power-on indications at both the surface sides of the top plate is put out of operation at the device capable of indicating the power-on state of the heating element of the electric ''kotatsu'' at the top plate surface. CONSTITUTION:In the electric ''kotatsu'', the heating element 4 is heated by turning-on a source switch 3 and at this time, magnetic flux 15 is generated in an iron core 2, because an exciting coil 2a is simultaneously energized by said turning-on of the source switch 3. The top plate 7 placed through a coverlet 6 on the ''kotatsu'' is equipped at its center with a detecting coil iron core 8 and a detecting coil 8a, which receive said magnetic flux 15. Transistors 9 and 10 are turned on by means of AC voltage generated in the detecting coil 8a in order to emit light from a light emitting diode element 12 with the power of the cell 14 so as to indicate that the heating element 4 is in operation. At this time, a light emitting diode element 17 is put out of operation by the action of a switch 18, which detects subject surface side is the upper surface side or the lower one. |
