This circuit with pressure sensor was obtained from the Encyclopedia of Electronic Circuits volume 5 of 1995. Note the construction of the sensor with rubber and conductors.
This useful circuit is used to test the insulation of cables, appliances, leaks in high voltage...
This class B circuit was found in the 1960 Mullard transistor reference manual. Transformers are...
This circuit is from the American magazine that no longer exists Science & Electronics,...