Found in an Electronics World of 1968, this circuit is indicated for applications in photography making the control of a camera aperture. The components are from the time.
Indicated by Popular Electronics to be used with a car headlight, this circuit can also have...
In this circuit of a 1970s publication, data from the coil to oscillate at the desired frequency...
This circuit was obtained from a Philips documentation from 1968. The transistors can be replaced...