| 摘要 |
PURPOSE:To reduce the size of a semiconductor heater and to simplify an energizing circuit to a semiconductor heater by switching energization to a semiconductor heating elements having positive temperature resistance coefficient in plural stages, thereby freely switching the quantity of heat. CONSTITUTION:All of an electrode plate 7, a radiation fin 8 and terminal board 9 are formed of aluminum, and a semiconductor heating elements 6 are conductively mounted. Intermediate terminal boards 10, 11 isolated from the space 12 to switch the quantity of heat are formed of aluminum. The elements 6, 6 are divided into sections A, C and B, D, and are energized and heated via external and intermediate terminal boards 9, 11. When closed by a switch 14, all of them are energized to strong heating, and when opened, only the sections A, B are energized to obtain weak heating. |
