An article in Radio Electronics magazine from November 1958 showed the construction of this tube audio oscillator. Note the use of lamps as a stabilizer to obtain better sinusoidal signals.
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...