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.
The frequency of this oscillator depends on the crystal used. The transistors are general purpose. We...
This circuit was suggested in an article in Radio Electronics magazine in January 1992. Other...
The coil of this receiver consists of 100 turns of wire 38 to 30 in a ferrite rod and the...