RPM Simulator

Thread Starter

kenzo42

Joined Feb 26, 2014
45

Coutesy of SgtWookie from thread http://forum.allaboutcircuits.com/showthread.php?t=28010&page=2


Sorry, some noob questions:

1) Is it possible to vary RPM w/ a pot in place of R3?
2) Is the wire loop the output?
3) The cap you mentioned (220uF) can go anywhere between pin 1 (on the 555) and pin 8 (on the 555)?

I'm trying to simlulate an RPM signal for an aftermarket ECU (Megasquirt) for a Miata - the tacho signal itself is a simple squarewave of (I believe) 0-12v amplitude, with one pulse per ignition event. If I try to read this on a multimeter, I just see a very low (and unsteady) voltage.

I'd rather not buy the Jimstim and I think it would be fun to make my first circuit. I'd like to test RPM on the ECU but also make a LED tachometer w/ shift light.
 

shortbus

Joined Sep 30, 2009
10,045
R2 is the pot that controls the "RPM".

By mentioning a car in your thread it will probably be closed soon. Against AAC terms of service, nothing against you. :)
 
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