This shield circuit with an optical coupler was found in an 90s EDN. The circuit can be used with voltages from 0 to 600 V with the indicated component values.
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
A The adjustable Q-factor rejector filter in the figure is based on two LM110. These integrated...
Found in Electronics Now this circuit can generate signals up to a few tens of Megahertz. The circuit...