Network supply circuit for LV load resistances - uses trial controlled by ignition circuit with schmitt trigger

摘要

The network supply circuit uses a triac (TC) receiving ignition pulses from an ignition circuit (5) during the positive half waves of the network voltage, with a charge capacitor (C2) connected in parallel across the load resistance. The ignition circuit (5) has a Schmitt trigger (6) with a first transistor (T1) controlled by a capacitor (C1) which is connected in series with a diode (D). A Zener diode (Z1) lies in parallel with the series circuit, the Zener voltage limiting the charge of the control capacitor (C1), which provides the ignition pulse energy. ADVANTAGE - Simplified ignition circuit.