Project 003 – Allowing for readout meter of choice

Revcounter Signal Conversion

This client wanted to use a classic moving coil RPM indicator on vehicles that didn’t have any electrical RPM signals available. He could not find any suitable revcounter that could be used in his application.

The solution was to built a small interface PCB that would use the ignition circuit signal and convert it to a signal that could drive the clients standard moving coil revcounters.

The PCB could also be used with an antenna to pick up the inductive signal from a spark plug cable to avoid the need to connect any wires to the ignition circuit. This made it very simple to switch the revcounter between different vehicles. The power supply was the standard vehicle battery.