This very low power amplifier is designed by Amperex for hearing aids. It is based on TAA370 which is not an integrated circuit that can be found today.
Using an era germanium transistor, this 1960s circuit reverses the phase of relatively low...
This step of two transistors has a high input impedance due to the use of FET. We can use BF245 for...
This simple Bargraph photometer with 4 LEDs was found in a 1997 documentation. The scale is...