This optical counter was found in a 1964 Electronics Design. It makes use of an uncommon optocoupler today, using emission lamp and a phototransistor.
This circuit retriggers when a new pulse arrives. It does this by discharging the capacitor. The...
This circuit was found in an Electronics Now of the 90s. It is intended for amplifying composite...
This circuit is from documentation from 1965. However, it can be created with modern transistors. Power...