CIRCUIT FOR DRIVING ELECTROMAGNETIC RELAY

PURPOSE:To drive the titled circuit by a single power supply by providing a coil of a single winding self-hold type relay, a capacitor and a switching element short-circuiting across the coil and capacitor in response to the potential of the switching element connected in series to the coil and capacitor. CONSTITUTION:A base of a transistor (TR) QN 10 is controlled directly by an input signal from an input terminal 1. The emitter of the TR QN is connected to ground and the collector is connected to a relay driving power supply +V via a capacitor (C) 4 and a coil (RL) 9 of a single winding self-hold type relay. The TR Q11 is connected in parallel with the RL9 and the C4 connected in series, and controlled by an A/D converter 5 detecting the collector potential of the TR QN 10. Thus, the single winding self-hold type relay is set by a high level signal fed to the terminal 1 and reset by the applied low level signal.