| 摘要 |
The present invention relates to an engine of a hot water circulating and heating tool, which is commonly called hot water mat, more specifically, to an external device for an engine where the operation of various sensors and the input and output operation toward a user are not stopped in the case that the engine is inclined or overturned while an AC heater is stopped, and a cord attached thereto. The engine is controlled by an external module comprising: a posture safety switch, an AC-DC power board, and a controlled heater switch through an AC-Dc control cord set (499). |
