With this circuit it is possible to use a frequency meter as a tachometer. The circuit was found in American documentation from the 90s. The phototransistor can be of any type.
The advantage of this circuit lies in the fact that it does not need a negative source to generate...
This simple audio generator with the 741 was found in a 90sTexas Instruments. The circuit...
With this circuit from an old 1973 publication it is possible to use a small speaker as a...