The high voltage power supply is connected to trigger unit through two, series 1 MOhm resistors. The avalanche transistor ZTX 415 (TO-92) has maximum voltage collector-emitter (VCBO) of 260 V (ZTX 415 Datasheet). It also possess high peak collector current of about 60 A with a pulse width shorter than 20 ns. Each avalanche transistor base is directly connected to emitter except the last one (Q1). Transistor Q1 is triggered via a control unit connected through a
100 Ohm resistor.