Found in documentation from the 1980s, this circuit can generate signals between 6 and 8 MHz. The frequency can be slightly varied in the setting. FET is a general-purpose type.
We found this circuit in a Popular Electronics of the 90s. The circuit still uses light bulbs, but...
This circuit is from Linear Technology 2005 documentation. The circuit is based on company...
The integrated circuit used in this power supply is no longer very common in power supplies today....