General Electric suggests this circuit in an 80's documentation. The circuit makes use of PUTs that are not common components today. Note the timing components that may change.
The FET for this circuit from a 1977 documentation can be BF245 or MPF102. The circuit measures...
This amplifier was suggested by the Texas Instruments linear applications manual of the 90s....
This circuit was obtained from Linear Technology documentation from the 80's. Powered by 5 V it...