This circuit was found in a 1965 US documentation. The circuit converts a DC signal to a 400 Hz AC signal. Transformer data was not provided.
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...
The LM143 is a high voltage operational amplifier not very easy to obtain today. The transistors used are...
This circuit found in old documentation is based on the 709 which is an operational amplifier that...