Suggested by National Semiconductor in documentation from the 90s, this circuit makes use of an operational of the time. The configuration can be applied to modern equivalent components
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...