Found in an Electronics World of 1968 this circuit can use any SCR and diodes depending on the load. The circuit is full wave and the unijunction can be 2N2646.
This circuit sensor is an NTC with a resistance of the order of 2k. The SCR can be from the TIC...
The load current can be adjusted up to about 1 A. The transistor can be TIP32 or TIP42. The...
This oscillator with common general-purpose transistors appeared in Radio Electronics magazine in...