This circuit was found in a 1967 Electronics World. We can design it with a BF245 for the FET and a BC558 for the bipolar transistor. The circuit has 3 scales and a 10 M ohm input resistance.
This circuit uses transistors from the time it was published but can be mounted with current...
This two-phase stepper motor circuit was found in an old documentation using an operational amplifier...
The integrated circuit used in this application is uncommon today and specific to the application, as it...