This circuit triggers a relay when the set temperature is reached. The circuit is from an old documentation. The relay may be equivalent according to the transformer secondary voltage.
Found in a Motorola documentation from the 70s, this circuit makes use of transistors of the time....
In the figure we show how to use common diodes to get a reference near 3 V in a car gearbox. The...
The transistors of this 12 V x 150 mA power source can be BC558 for PNP and BD135 for NPN. The...