The frequency of this clock oscillator is given by the crystal. The trimmer sets the ideal starting point for oscillations.
This circuit is from a 1974 publication by Motorola. The unijunction may be 2N2646 and bipolar BC558...
In figures 1 and 2 we have two current drains that can be made with operational amplifiers and...
This circuit appears in several points of our site, including used in practical projects. The...