Patent ID: 6512361
Filing Date: 2003-01-28
Classification: G01R

Abstract:
A portable hand-held automotive circuit tester for detecting voltages in different voltage ranges corresponding respectively to different-voltage automotive electrical systems, the tester comprising:a housing having a probe tip and a ground connector projecting therefrom and having plural groups of indicator apertures therein respectively corresponding to plural different voltage ranges; and a voltage detector disposed in the housing and including an input circuit coupled to the probe tip and producing an input signal from the circuit being tested, a power supply circuit, a reference circuit coupled to the power supply circuit and producing a plurality of reference signals arranged in sets corresponding to the plural different voltage ranges with each set incrementally graduated from a low amplitude to a high amplitude, a comparison circuit coupled to the input circuit and to the reference circuit and to the power supply circuit and comparing the input signal to each of the reference signals, and plural groups of indicators respectively corresponding to the sets of reference signals and respectively viewable through the groups of apertures and coupled to the comparison circuit so that only one group of indicators will be operable, depending on the voltage of the automotive electrical system being tested, the comparison circuit being responsive to the input signal for energizing the indicator corresponding to the highest reference level which the input signal equals or exceeds.