The circuit given here is of digital voltmeter with LED 7-segment display using the ICL7107. It measures voltage from 0.00V to 99.9V. ICL7107 is a 3 1/2 digit A/D converters with LED 7-Segment Driver.
The Intersil ICL7106 and ICL7107 are high performance, low power, 31/2 digit A/D converters. Included are seven segment decoders, display drivers, a reference, and a clock. The ICL7106 is designed to interface with a liquid crystal display (LCD) and includes a multiplexed backplane drive; the ICL7107 will directly drive an instrument size light emitting diode (LED) display. Continue reading ICL7107 Digital Voltmeter