Found in National Semiconductor documentation, this logarithmic meter is powered with a voltage of only 1.5 V. Equivalent operational amplifiers can be tested.
This circuit is from an Argentine publication from 1973 but can be assembled with BC558 and BC548...
This two-stage amplifier circuit with RC coupling was obtained in a 1977 Radio Handbook. The...
This control for motors up to 1 A was found in a Siliconix documentation using its own component....