I have build a voltmeter with icl 7106 "panel meter dpm 952" but i want to upgrade it and dont know how to do it. I have heard that you can with one or two additionals operating amplifiers make such circuit that the icl can measure itself power supply.
So i want to connect the voltmeter with operating amplifiers to the power supply and on the screen will show the voltage that powers the icl 7106 circuit