Found ina 1970 American documentation this fast-reading circuit uses a photodiode. Transistors support modern equivalents. The circuit can be used as a shield.
The output current of this converter from positive to negative -5 V is 1 A. The circuit is from...
Found in a 1980s documentation, this circuit makes use of components from that time. Modern...
This sophisticated moving bar indicator circuit with the LM3915 is from a Radio Electronics...