Safeguard feature in a circuit arrangement for protecting an electrical

Abstract

A safeguard feature prevents supply of voltage to an electrical device in the event a protective element is no longer reliably connected in a circuit arrangement for protecting a susceptible component from inadmissible voltage values. The protective element in the circuit arrangement is often conveniently provided in the form of a suppressor diode, which is connected in parallel with the susceptible component to be protected, and which experiences breakdown in case of excessive voltage, thereby causing a short-circuit in the power supply. In the event of such protective response, the suppressor diode may heat up considerably, and that the solder used for electrical and mechanical attachment may liquefy or evaporate. As a result the suppressor diode may become completely or partially unsoldered, so that a reliable protection of the susceptible component is no longer ensured by the shorting of the circuit thereacross. At least one of the conductors going from the power supply system to the protected component is therefore provided with a break location, and one of the connections of the suppressor diode bridges the break location prior to breakdown. If the suppressor diode then becomes unsoldered or otherwise detached from the rest of the protection circuit, the susceptible component is nevertheless protected from the inadmissible voltage since it is isolated therefrom by the discontinuity in the conductor provided by a separation therebetween defined by the break location.