Tach wire readouts (digital or analog)

[dreed75]

2G Eclipse N/T

I was wondering if the signal from my tach wire (right off the ECU) was a digital or an analog signal. I want to somehow get the signal into a digital readout but don't know how to convert it. I can't tell what it is by hooking up a multimeter because if there are pulses, the multimeter doesnt sample it fast enough to be able to tell. I also don't have an O-scope. Does anyone have any experience in this? And also, how does the tachometer itself actually work? Is there some conversion going on inside the tach? Thanks.

 

[GSGoinFast]

2G Eclipse N/T

I was wondering if the signal from my tach wire (right off the ECU) was a digital or an analog signal. I want to somehow get the signal into a digital readout but don't know how to convert it. I can't tell what it is by hooking up a multimeter because if there are pulses, the multimeter doesnt sample it fast enough to be able to tell. I also don't have an O-scope. Does anyone have any experience in this? And also, how does the tachometer itself actually work? Is there some conversion going on inside the tach? Thanks.

the only help i can give you, and i dunno if this even helps, but the S-afc gives you a digital read out of rpm's, by just tapping into the tach wire. sorry thats all i got .

 

[dreed75]

Yeah I know about the computers you can hook up but there is no telling if there is some A/D converting going on or what.

It is worth noting that these computers can be installed on almost any type of car and number of cylinders so maybe there is some standard on how RPMs are calculated. Does anyone have any insight on this?