Safety circuit for motor vehicle additional heater - has flame monitor and a circuit for modifying charging of a capacitor

摘要

The safety circuit for an additional heater is a motor vehicle has an RC circuit and a load side transistorised amplifier circuit. When the heater is switched on and in the case of absence of flame, or in the case of flame failure, it produces a delayed switching off signal. The response time varies automatically with the given fault and the delay is long for the absence of the flame on starting, and in the case of flame failure during operation the response time is short. The charging circuit has a transistor stage actuated by a low ohmic heating plug, and this system reduces the charging resistances of the capacitor.