Found in an old Popular Electronics, this circuit warns when a remote lighting system is not working. The circuit uses an LDR as a sensor and the components used are quite common today.
This circuit is from an English book from the 1980s. Transistors can be general-purpose types of...
This circuit from the 80's can be easily implemented but needs some changes to avoid problems with...
The presented circuit provides an output voltage proportional to the input current, according to...