Temperature interface (CB20543E)

This temperature sensor shield or interface was found in a PC English documentation from 1996.

Battery Charge & Discharge Indicator (CB4986E)
We find this circuit in an English 80's documentation. The circuit can be made with more modern...
Sawtooth Generator (CB1358E )
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
Telegraphy Practice Oscillator (CB4200E)
This is one of many Morse code audio oscillators that can be found in this section. The circuit...