Using an LDR as a sensor, this circuit is from the Radio Electronics magazine of December 1984. The operational amplifier is the 741 and the source must be symmetrical.
This circuit was taken from Maxim documentation from the 90s. The components are from the period....
Here we show how a Constant Current Source can be created in the Multisim Blue using a common BJT...
This circuit has several features, such as timing to activate and deactivate, in addition to a...