This circuit, found in 1993 documentation, is the traditional relaxation oscillator configuration with unijunction transistor. The frequency depends on C and the resistance value R.
We found this circuit in the July 1969 Radio Electronics magazine. The circuit uses a coupler made...
The FET of this circuit of a 1971 publication may be the BF245. The circuit serves as a voltage...
This circuit was obtained from an American documentation from 1969. The operational amplifier and...