This diagram from a 1967 documentation shows how to switch high voltage neon lamps with 5V TTL outputs. The circuit can be adapted to function as a shield.
This circuit consists of a voltage regulator for 6 V batteries with a very low voltage drop. The...
This BFO or OFB for listening to SSB (Single Sideband) signals was found in the January 1996 issue...
We found this circuit in a European publication from the 1990s. Transistors are still common types...