We found this circuit in a 1982 documentation. It uses a CA3140 or equivalent operational amplifier and does not require a symmetrical source. The output is 1 Vpp wide.
Found in a Motorola documentation from the 70s, this circuit makes use of transistors of the time....
This is one of many Morse code audio oscillators that can be found in this section. The circuit...
Here we have the way to activate two common cathode displays with 4026 integrated circuits. The...