- on Test & Measurement
- Published in issue 7/2008 on page 73
Automatic Range Switching
Most DVM modules are based on the well-known ICL7106 IC. They operate from an ordinary 9-V battery, and they only provide a fixed measuring range (200 mV or 2 V). The accessory circuit described here converts a DVM module into a voltmeter with 20-V and 200-V measuring ranges, with the added bonus of automatic range switching.