| 摘要 |
PURPOSE:To remove a heat sensitive element and simplify the constitution of a titled circuit by detecting the unbalance of a bridged current detecting circuit caused by local temperature rise of a heater. CONSTITUTION:When a switch S is turned on, a commercial electric power source E is connected to a heater H. When the temperature of the heater H rises evenly as a whole, a current does not flow into current transformrs CT1, CT2. If a part of the heater H rises by putting a cushion or the like on a part of the upper surface of an electric carpet, bridge balance is destroyed and current flows into the current transformers CT1, CT2. Consequently, an output is applied to a driving circuit OUT, switching contacts C, C' are switched and voltage is supplied from the secondary winding to the heater H. |
