This circuit was found in a Texas Instruments documentation from the 1980s. The circuit monitors engine temperature by warning of engine warm-up and warning when the fan is on.
We found this circuit in the 1982 Selezione Radio magazine in Italy. The circuit uses an...
This circuit was obtained from Dutch documentation from 1967. It uses transistors of the time...
This circuit was found in a 1966 General Electric book. The triac and the day are from that time...