Combination high impedance continuity and voltage indicating instrument

An electric testing instrument comprising:

• an amplifier circuit having a pair of input terminals comprising a probe and a second terminal adapted for manual engagement by the user for completing an input circuit through the body of the user, and an output circuit comprising in series a collector, an emitter, a battery and a current responsive indicator;
• said second terminal being connected to the side of said battery connected to said collector and having a polarity opposite to said emitter;
• said indicator providing a manually discernible signal at and above an operating current flow in said output circuit, said amplifier having a gain of at least about 25,000 and providing said operating current flow in said output circuit when said input circuit is biased with an input current as low as about 1 microampere;
• said input circuit providing said input current derived solely from said battery when said input terminals are connected across a resistance as high as at least 1 megohm, said input circuit providing said input current when said probe is connected to a conventional live power line providing approximately 110 volts AC and said second terminal is manually engaged.