摘要 |
An improved apparatus for use in the turn-direction indicating system of a vehicle having directional lamps energized by a battery through a current detecting resistor, a relay and a direction selecting switch. The relay is energized to close periodically in response to periodic pulses produced by a semiconductor integrated control circuit so that the directional lamps flash periodically. A protection circuit which is connected in series with a resistor across the battery render the output transistor of the semiconductor integrated control circuit ON in response to an excessively large positive voltage so that the electric current which flows through the output transistor is limited by the inherent resistance of the relay coil connected in series with the output transistor. A diode which is connected in series with the relay coil render the output transistor ON reversely in response to an excessively large negative voltage so that the electric current is limited by the relay coil.
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