This circuit, from the 70's, can be assembled with a more modern FET like the BF245. The circuit is powered by a 9 V battery, as its consumption is very low.
Found in Popular Electronics from March 1957, this circuit is based on transistors from the time....
The voltage gain of this circuit found in the 1982 SGS Linear Integrated Circuits manual is 10...
This circuit, found in an English publication in 1982, has an inverted sequential effect, as the...