pete95zhn

Does anyone know the calibration of KLR pin #5 output voltage, ie. signal to instrument cluster boost gauge?
Is it linear or not, and how many Volts are eg. -0.6, 0 and 1.0bar? ( 0.4, 1.0 and 2.0 according to gauge )

TIA, Pete

pete95zhn

bump

Anyone?

RKD in OKC

Looks like you are going to have to put a meter on it to find out.

Tom M'Guinn

As far as I can tell, it is a pulse width output with very low voltages. I posted my findings here I believe. I started to make a circuit to remap the factory gauge on a 0-30psi scale, but haven't gotten back to it in a while. The pressure sensor in the KLR didn't have the needed range, so I was planning to re-condition the signal from my zeitronix boost sensor to drive the gauge.

pete95zhn

Thanks, I did some searching and there's general consensus that it a PWM signal. What's missing is amplitude, pulse width and frequency.

It would be pretty easy to do testing if there just were oscilloscope and hand held boost/vacuum pump available.

Transaxle

Depends on where you take the signal. It is taken directly from the sensor and just filtered. If you take it from #5, you will see a linear signal with a 0-5V range. With the boost gauge connected, the signal is divided by 5 to give you a 0-1V signal.

It is taken on the KLR board before the internal calibration stage, so you must handle the calibration by yourself.

Sorry to disturb the general consensus...

Tom M'Guinn

No apologies needed -- happy to get to the bottom of it. So where does the calibration occur? In the gauge? When you look at the signal with the gauge connected, you see 0-1 volt. Is that just the filtered 0-5v sensor output divided by 5? If so, is the 0-5 linear from 0 to 2 BAR absolute pressure?

pete95zhn

Thanks Transaxle,

just few thing for clarification:

- the boost gauge itself is fed with linear 0-5v signal, yes or no...?
- as Tom asked, is 0V = 0bar and 5V = 2bar ?

If these both apply, it would be fairly easy to recalibrate boost gauge to show 0-2 bar boost, and get this signal from stand-alone EMS.

Bri Bro

This is a chart of my datalogger for the boost signal. The range is set to 5 volts so:
100%=5 Volts
20%=1 Volt
Sample rate was set a 20 samples/second
Assume 1 Volt =14.7PSI (1 bar)
I had the boost set at 18 PSI since it was a nice cool day at Mid-Ohio. The reading on the chart were around 42% or 18PSI.