LED Tachometer

Not open for further replies.

Thread Starter


Joined Dec 13, 2007
I found this schematic for building an LED tachometer which uses an ignition coil signal. The LEDs light up sequentially as the Engine Revs increase, etc. I wanted to add an additional feature, and was wondering if anybody could help me figure out how to do it. Basically, what I am trying to do is have all of the LEDs start flashing/blinking every 20 milliseconds or so when the engine is over a certain RPM. Can this be done without too much complexity? Thanks for your help!



Joined Mar 24, 2008
The All About Circuits forum Administrative Team has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

This thread is against the AAC forum rules, Chapter 6, as seen here:


Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

Please try to understand the reasons behind this action, and feel free to browse and use the forums.

You might find answers to your questions in one of these forums:

Not open for further replies.