| 摘要 |
PURPOSE:To use together plural heating devices in a simple constitution and high stability. CONSTITUTION:The heating temperature of an electric carpet 5 is set by operating a temperature control knob 24 of a controller box 29 and therefore operating the resistance value of a variable resistance 11. That is, the potential of a sense signal input terminal 9b of a control circuit 9 is dropped with reduction of the value of the resistance 11. The circuit 9 is actuated only when the impedance of a heat-sensitive layer 10b of a heat sensor 10 is much lowered. In addition, a contact 7a of a relay 7 is not opened. Therefore a higher heating temperature is set. In case both the carpet 5 and an electric foot warmer 17 are used at a time, a power supply plug 19 of the warmer 17 is connected to a plug socket 20 of a joint box 22 of the carpet 5. Thus, a switch 21 is automatically opened and a temperature setting resistance 12 of the warmer 17 is connected in series to the resistance 11. Then the temperature is set automatically at a level lower than a case where only the carpet 5 is used. |
