We found this frequency meter circuit in a 1974 documentation. The circuit is powered by 12 V and has 8 digits. Changes can be made using a prescaler to reach higher frequencies.
Although it is made for old oscilloscopes up to a few megahertz, this circuit converts your device...
This electrochemical circuit monitors the conductivity of the oil indicating when to change it. The...
This circuit came out in a publication called Electronics Handbook of 1993. The circuit triggers an...