Found in a 1967 Ferranti documentation, this circuit uses a LDR from that time as a sensor. Transistors can be replaced with modern equivalents.
The circuit in the figure can be used to trigger a triac or even a comparator in a project that...
Suggested by a 1990 book for amateurs, this circuit makes use of an integrated component that is...
Using circuits from Analog Devices, this circuit does not need a symmetrical power supply. It is...