Series inverter without gate control

In commonly used inverters, the ac power is supplied to the load by the switching of gate-driven thyristors. The gating signals are supplied by an external triggering circuit. The inverter presented by the authors does not have a separate triggering circuit. The self-excited sinusoidal oscillations are obtained by using the capacitor voltage of the series ringing circuit as a gating signal. This type of inverter is very simple and useful if the load condition falls within the stable range of operation. The paper describes the circuit and it presents the analytical limits of stable operation. Experimental results are compared with analytical results.