Found in a 1967 General Electric documentation this circuit uses unijunction transistors that may be equivalent to those indicated. The number of stages can be modified.
This circuit is from an ancient American documentation. The coil is frequency dependent and the...
We found this circuit in a 90's Popular Electronics. The circuit produces a loud sound if S2 is...
This 2.2 Hz to 24 kHz filter was found in the February 1995 issue of Electronics Now magazine. The circuit...