| 摘要 |
<p>PURPOSE:To lower the current driving capacity of transistors for limiting flowing currents and for a charging pilot lamp and scale down chip size, and to enable a change into a monolithic IC for control at low cost by providing a constant-voltage power supply generating voltage lower than battery voltage as the driving power supply of these transistors. CONSTITUTION:A surge waveform generated at a time when the terminal B of a battery 2 and load 3 are interrupted simultaneously during the power generation of a charging generator 1 and a load dump surge is generated is applied to terminals B, S, L. Surge voltage applied to the terminal B is absorbed by a resistor 24, a capacitor 21 and a Zener diode 25 in a constant-voltage power supply VCC at that time. The base currents of a transistor 12 for limiting flowing currents and a transistor 13 for driving a charging pilot lamp are supplied through resistors 14, 15 respectively from the constant-voltage power supply VCC, and the base currents of these transistors 12, 13 are not increased even when high voltage such as the load dump surge is applied to the terminal B.</p> |
