Voltage protection circuit for multi-drop bus of an automated coin vending machine

摘要

A voltage protective circuit for an electronic device comprises a metal oxide varistor for eliminating spikes above a first level, and a Zener diode and a transistor connected in series through a resistor with the metal oxide varistor for eliminating spikes above a second level. The voltage protective circuit can be utilized in a separate, plug-in voltage protector for a vending machine with a multi-drop bus.