The circuit in the figure uses two operational amplifiers: an LM101A and an LM102. Diodes admit equivalents and resistors do not have to be accurate. The power supply must be symmetrical.
This simple capacitor tester, already covered in other articles in this section and on the...
We found this circuit in a 1964 Electronic Design. The triac and SCR can be replaced with modern...
This circuit combines field effect and bipolar transistors to obtain a 20 gain with a pass band...