IC engine preheater control - has electronic coupling to energise heater when starter is operated

摘要

A starting switch connects a supply to a timing circuit which energises a Schmitt trigger. This operates a relay which energises the preheating circuit. At the end of the set time the trigger operates and the preheating stops. A further position of the starter switch energises the starter motor. In this position a supply is put on the trigger circuit through a diode so as to block the trigger action. The preheating circuit is thus energised regardless of the state of the timer.