Circuit testers

Abstract

A circuit tester (1) for testing circuit integrity in a series-wired string of Christmas fairy lights powered by domestic mains electricity. The tester comprises or includes a housing; a probe including a pair of matching current sensors (1,2) protruding from the housing, the probe being adapted to be positioned between a respective pair of wires extending from a fairy light bulb socket, each sensor in the probe being electrically connected to a respective one of a matching pair of signal amplifiers (3,4) to provide a pair of amplified signals, one for each sensor; a logic gate (5) for receiving amplified signals output from the pair of signal amplifiers and comparing said signals for matching characteristics, the gate providing an output signal to a first display (6) on or in the housing indicative of received and matching signals and a, different, output signal to a second display (7) on or in the housing indicative of received mismatching signals from the amplifiers, the latter thereby indicating a discontinuity in that part of the circuit being tested between the pair of wires, such as by a broken fairy light bulb in that part of the circuit therebetween.

Dependencies are inferred from the claim text.