
- In higher voltage supplies a pi smoothing circuit of two capacitors and a choke is normally used (a) — capacitor input circuit
- In low voltage supplies, (b) a zener diode (with no load the diode passes load current), (c) a zener diode and pass transistor (emitter follower), or (d) an i.c. voltage regulator are commonly used; the i.c. requires C2 and C3 (low-inductance tantalum) for stability