This circuit is from a 1968 Electronic Design. The characteristics of the output transformer are not given and the transistors are of the time. The circuit provides a power of a few watts.
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...