Electronic switch for PTC load - has adjuster between supply voltage source and load, switchable by control voltage.

摘要

The switch has a current meter (R5) picking-up current flowing through a PTC load (G1). Behind the meter an evaluator (T1-5, DV1-3, P1-3, R1-8, D1, K1, LED) is coupled for actuating an adjuster (T5) of the electronic switch. The adjuster limits a top limit value (Ref3) at a higher load current to a preset, lower, constant limit value (Ref2). After the top limit value has been exceeded, the evaluator switches again the adjuster when the load current has dropped to a still lower limit value (Ref1). Pref. the adjuster is also controlled by a temp. monitor (TK). USE/ADVANTAGE - For overload and short circuit protection. Improved operation for attaining high-ohmic state.