This General Electric circuit, in a documentation from the 1960s, allows the use of high resistance resistive sensors with unijunction transistors in a relaxation oscillator.
This circuit was found in an old publication about transistors. The circuit can be used to drive...
Using a symmetrical source this circuit reverses the rotation of a small motor through light...
This circuit was found in a 2005 Linear Technology documentation. The circuit is based on LTC4213...