| 摘要 |
PURPOSE:To facilitate easy handling, by providing a transistor within a limiter circuit for excessive current in order to secure a protecting function if an output terminal is connected mistakenly to a power supply terminal. CONSTITUTION:When the input signal supplied from a terminal 1 exceeds a fixed level, the product of the emitter current of a transistor TR10 and a resistance 7 exceeds the bias voltage value in the base-emitter forward direction of a TR8. Therefore a conductive state is secured between the collector and the emitter of the TR8. Then the input signal supplied to the base of a TR10 is bypassed to actuate a limiter. While the base potential of the TR10 rises up and the voltage drop of the resistance 7 increases suddenly if a terminal 2 is connected directly to a power supply +E by mistake. As a result, an output TR3 is broken and protected from a current breakdown. |
