This circuit operates with an AM radio tuned to or near 900 kHz if there is a station at this location. The coil consists of 60 + 40 turns 28 on a ferrite rod.
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
This interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...