We found this circuit in a 1980s documentation. Equivalent components can be used. The circuit senses temperatures in the range of 0 to 50º C and uses a transistor as sensor.
This circuit is from the time when cars used contact breakers. This 80's version measures the dwell...
The advantages of using Schmitt Inverters (74108) or Schmitt NAND gates (4093) in oscillators lie...
We found this circuit in an American 1980s documentation. The operational ones used are not common...