attention clever people

[porter_jamie]

maths n' stuff

sensor A

1v=0 bar

5v=10bar

sensor B

1V=0bar

5v=16bar

both linear.

if you use sensor B, but with sensor A settings in the readout, and get a reading of 5.5bar, how many bar do i really have. (i hope itro 3)

havnt had much sleep and my head hurts, over to you

answers with working please!

J

[rerun]

I have bad english, but I would say more like 8,8bar?

[TriGGer]

If readout shows 5.5 bar calibrated for A then it is receiving 2.75v

If sensor B is sending 2.75v then the pressure must be 8.8 bar

This is because with A - 1v = 2 bar , hence 1 bar = 0.5v

however B - 1v = 3.2 bar , hence 1 bar = 0.3125v

So if the sensor displays 1bar for every 0.5v and its displaying 5.5bar it must be receiving 2.75v from sensor B.

If sensor B is sending 2.75v it must be sensing 8.8bar.

*maybe

[porter_jamie]

If readout shows 5.5 bar calibrated for A then it is receiving 2.75v

If sensor B is sending 2.75v then the pressure must be 8.8 bar

This is because with A - 1v = 2 bar , hence 1 bar = 0.5v

however B - 1v = 3.2 bar , hence 1 bar = 0.3125v

So if the sensor displays 1bar for every 0.5v and its displaying 5.5bar it must be receiving 2.75v from sensor B.

If sensor B is sending 2.75v it must be sensing 8.8bar.

*maybe

anyone know what fuel pressure an er6 runs? (EDIT changed the fuel pump and fuel pressure reg for an ER6 pump/reg thing cos it's smaller.)

i assumed it was 3 - it can't be 8 can it? it might explain why i had to take nearly 50% out of the map at the dyno though, running a new single injector (668cc@3bar) instead of twin 250cc@3bar

trying to mackle up a pressure gauge to see what is going on. will put in the proper settings and see if it goes up to 8 bar - hope not!!

[TriGGer]

I assumed you meant 0v = 0bar and 5v = 10bar though.

The calculations are different for 1v = 0bar and 5v = 10bar.

ie 4v+- = 10bar hence 1v = 2.5bar

So, 1bar = 0.4v for sensor A and

4v+- = 16bar hence 1v = 4bar

So, 1bar = 0.25v

If the readout shows 5.5bar and hence receives 2.2v then for B to send 2.2v it must be reading 8.8

Either way its 8.8

[foo]

Sorry, fucked up the range of sensor A first time round. Bottom axis is volts, 1 to 5, left axis is bar 0-16. Hope this helps.

edited for stupidity.

[porter_jamie]

Sorry, fucked up the range of sensor A first time round. Bottom axis is volts, 1 to 5, left axis is bar 0-16. Hope this helps.

edited for stupidity.

foo - cant see the piccy. not sure if it is a setting thing on my laptop? i'm just getting a stupid 'x' where the piccy should be

[foo]

foo - cant see the piccy. not sure if it is a setting thing on my laptop? i'm just getting a stupid 'x' where the piccy should be

Seems OK from here. It's just a bog-standard .png file hosted on tinypic --unless tinypic had taken a shit when you were trying to look at it. I've just fired up Internet Exploder, and it works fine from there, as well as my normal Firefox. Sorry I can't be more help.