The circuit is built around a single transistorised blocking oscillator. An important element in this circuit is the transformer. It can be fabricated on easily available ferrite cores. Two E sections of the core are joined face-to-face after the enamelled copper wire wound on former is placed in it. The details of the transformer windings are given in the Table.
In this configuration, the primary winding and the feedback winding are arranged such that a sustaining oscillation is ensured once the supply is switched on. The waveforms duty cycle is asymmetrical, but it is not very important in this applicati