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Resistance to voltage conversion
Posted: Sun Jul 28, 2013 5:58 pm
by Steve
I have now fitted a new air temp sensor and a new oil temp sensor. They come with the temperature vs resistance table but I need to convert this into voltage to setup the linearisations in the sensor settings.
How can this be done?
Cheers
Steve
Re: Resistance to voltage conversion
Posted: Sun Jul 28, 2013 7:18 pm
by secure
I have made a worksheet in last years. It calculates the voltage multiplier with the entered pull-up resistor value. Syvecs is 3000 ohm.
so here it is..(revised)
http://www.syvecs.co.uk/forum/download/ ... 8af3d9452e
If you need more voltage resolution take a look at interpolation page on the same sheet.
Cuneyt
Re: Resistance to voltage conversion
Posted: Sun Jul 28, 2013 8:11 pm
by Steve
Excellent, thanks for that
Is it possible to change the sensor breakpoints or is it a case of matching it up as best as possible to the nearest voltage point?
Re: Resistance to voltage conversion
Posted: Sun Jul 28, 2013 10:00 pm
by TimH
If these are sensors supplied by me, then there are Syvecs linearisation database files on the website, to save you having to do this.
If not, then simple ohm's law applies, based on a 5V supply and a 3K pullup in the Syvecs.
And, yes, you can define all the points yourself.
Re: Resistance to voltage conversion
Posted: Sun Jul 28, 2013 10:05 pm
by Steve
I have set most of it now I think, I have set them as close to the current breakpoints using the excel sheet above.
With how they were set previously the ECU was seeing ACT of 60 when it should have been 30 and EOT of 160 when it should have seen 90 odd. So they were a little out.
The sensors were from EFI-tuning.co.uk.
Re: Resistance to voltage conversion
Posted: Mon Jul 29, 2013 1:36 am
by secure
Tim is right please check again the pull up resistor value. It should be 3000 ohm not 3300.
I revised the sheet as well.