This circuit was found in a 1980s documentation. The circuit uses common components having an output of 10 Hz per centigrade degree of variation. The sensor is a transistor.
This is a very simple motor drive circuit with an LDR. The circuit simply powers a small motor. We...
This plug-in control was found in General Electric documentation from the 1970s. The SCR can be...
This circuit from an old 1978 publication uses germanium transistors but can be implemented with...