This circuit was found in Motorola documentation from 1966. The lamps are according to power and current according to the components used which are uncommon today.
The figure shows how to couple two CMOS circuits using an optical coupler to achieve isolation. The...
This grid-dip meter was found in a Japanese publication from the 1960s. The FET can be replaced by a...
Using a period sensor, this circuit was found in the February 1986 issue of Radio Electronics...