Found in a 90s American documentation, this circuit that was used in cars of the time, detects low temperatures and light by activating a warning relay.
This circuit was found in a 1987 edition of the United States' Hands-On Electronics magazine. The...
We found this circuit in an old English publication. The resistor not indicated can be 2k2 and the...
This circuit was found in a Popular Electronics from the 90s. It uses a LASCR which is a photo-SCR...