omega 24 v6
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| posted on 24/8/11 at 09:33 PM |
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What size pull up resistor
OK first the facts.
I'm fitting a dash2 digi dash from race technologies to a renault clio.
I BELIEVE the fuel tank sender to range from 0 to 300 ohhms.
I also BELIEVE that full is 0 ohms and empty is 300 ohms
The dash does not read resistance and as such needs a resistor added between v5 ref and the signal input ( potential divider setup) like this
http://www.electronics2000.co.uk/calc/potential-divider-calculator.php
This is the setup
http://www.race-technology.com/wiki/index.php/HowDoI/ConnectA1Or2WireSensor
The max current draw from the 5v ref is 100 milliamps ( and there is already a gear indicator wired to it)
So what value of resistor should I use as R1 in order to acheive what is required.
Over to the electronic gurus.
Thanks in advance.
[Edited on 24/8/11 by omega 24 v6]
[Edited on 24/8/11 by omega 24 v6]
If it looks wrong it probably is wrong.
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matt_claydon
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| posted on 25/8/11 at 06:49 AM |
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Around 300 ohms would be fine. This would give you a voltage range of 0-2.5 v, with a maximum current of I=v/r = 5/300 = 17mA.
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omega 24 v6
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| posted on 25/8/11 at 11:10 AM |
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Thanks for that Matt .
1/4 watt big enough??
i presume P=V*I
P= 5*0.017
P=0.085
[Edited on 25/8/11 by omega 24 v6]
[Edited on 25/8/11 by omega 24 v6]
If it looks wrong it probably is wrong.
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