Abstract: A current controlled oscillator includes an optocoupler driven by a control current; a diode bridge comprising four high speed diodes where the polarized input receives signals from an output transistor of the optocoupler; a resistor connected between the transistor output of the optocoupler and the polarized input of the diode bridge; an inverting Schmitt trigger having well defined low and high thresholds where the inverting input and an output are connected to a non-polarized input of the diode bridge; a timing resistor connected between the input and output of the Schmitt trigger; a timing capacitor connected between the negative input and ground of the Schmitt trigger; a pair of voltage references establishing the low and high thresholds of the inverting Schmitt trigger.

Abstract: A self oscillating power converter utilizing a pair of MOSFET transistor switches in a half bridge configuration wherein the junction of the two transistors is coupled to a reactive network which in turn is connected to an output rectifier. The gate-to-drain inter-electrode capacitance of the switching transistors serves as the sole means of sustaining oscillations. Oscillations are started at the gate-to-source electrodes of the transistors by a startup circuit. The frequency of oscillation is determined by the gate-to-source capacitance of the transistors and the inductance of the drive transformer which couples the source-to-gate electrodes of the transistors to each other. The drive transformer is provided with a means of varying its inductance thereby changing the switching frequency so as to regulate the voltage.