Electronic unit for car occupants safety device

摘要

An electronic unit used in a safety devices for car occupants has a coil as a first energy store and a condenser as a second store. There are two controlled switches (s1,s2) operating in similar fashion by a circuit so that in one stage, the coil(l1) is supplied and in the second stage, the condenser(c2) is charged up. The switches operate depending on a current determined from a measuring resistance(r7) in series with them. The switch control is a PWM one, itself controlled through a zener diode which stabilises the output voltage(u2).