| 摘要 |
PURPOSE:To reduce the loss at operating time and to effectively start by operating a switching element by using a starting resistor having a positive temperature coefficient thermally coupled with the element. CONSTITUTION:A starting resistor 6 having positive temperature coefficient coinciding as much as possible with the temperature characteristic of a current amplification factor hf of a switching transistor 3 is mounted in contact with a heat sink plate 7 by mounting fittings 8 near the transistor 3 mounted in contact with the plate 7. Since the temperature rises by self-eating if the transistor 3 is once started, the resistance value of the resistor 6 similarly rises to flow a base current corresponding to the temperature at that time, and the power consumption thereat is reduced. |
