Tach reference voltage

[desert_gypsy]

Does anyone know the tach reference voltage for 6,500 rpm? I thought I'd ask before I go stabbing wires and making a shitload of noise in my driveway :rolling:

 

[desert_gypsy]

ttt

 

[03cobra#694]

Not sure what`re you`re asking,but pin#26 lg/wh is coil#1 that you would use for a tach or shift light.

 

[desert_gypsy]

Not sure what`re you`re asking,but pin#26 lg/wh is coil#1 that you would use for a tach or shift light.

Wow, I feel dumb. I suppose the reference voltage would be 12V, but completely unrelated to engine RPM, seeing as it's just a trigger wire. I suppose I just need to model the pulsewidths of the signal relative to to engine RPM. I'm attempting to design an inexpensive analog alternative to Autometer's tach controller module. It will consist of a single HILED with an adjustable trim pot controlled module, no larger than a half dollar.

 

[fiveoh2go]

Wow, I feel dumb. I suppose the reference voltage would be 12V, but completely unrelated to engine RPM, seeing as it's just a trigger wire. I suppose I just need to model the pulsewidths of the signal relative to to engine RPM. I'm attempting to design an inexpensive analog alternative to Autometer's tach controller module. It will consist of a single HILED with an adjustable trim pot controlled module, no larger than a half dollar.

Reference voltage for various sensors in most vehicles is five volts. That would be my guess.

 

[desert_gypsy]

Reference voltage for various sensors in most vehicles is five volts. That would be my guess.

I understand that, but the coil trigger wire is 12V, and it just alternates on/off.