Found in 1968 Mullard documentation, this circuit uses period components. The transistors are matched pairs and the sensor is an Indian photocell of the time.
This LED indicator circuit uses an LM339 comparator. The circuit was found in the January 1995...
This version is one of many that can be found on our website. We found it in Radio Electronics from the...
Found in a 2005 Linear Technology application manual, this circuit provides outputs from a current...