This circuit converts voltages from 5 to 12 V at voltages of 100 to 400 V. The transformer has a primary voltage of 110 V or 220 V and a secondary voltage of 5 to 12 V with a current of 300 mA or more. The transistors of the multivibrator can be the BC548 and the power transistors can be the BD135 or TIP31. The diodes of the bridge are 1N4007. The circuit is from a 1977 publication.