This 4-transistor amplifier can work from 4.5 or 6 V power supplies. We found it in a Mullard transistors manual from 1960. The transistors are from the time.
Texas Instruments UCC21225A is available from Mouser Electronics. It is an isolated gate driver...
We found this circuit with very high input resistance in an old documentation. The circuit is still...
This configuration was found in a 1976 publication. The outputs of the logic circuits are applied to...