matt_claydon
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| posted on 5/9/06 at 07:22 AM |
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Electronics experts - getting linear output from log potentiometer?
I've got a logarithmic pot that I need to get a linear output from. I've found lots of info on the net about getting a log output from a
linear pot - eg http://www.maxim-ic.com/appnotes.cfm/appnote_number/838 but nothing the other way around.
Is this possible? If so, how do I do it?
Cheers,
Matt.
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smart51
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| posted on 5/9/06 at 07:40 AM |
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The best way is to change it with a linear pot. Mapin.co.uk or RSWWW.com will sell you one. They are cheap.
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matt_claydon
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| posted on 5/9/06 at 07:50 AM |
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Yeah, problem is that this is the TPS on my throttle bodies and fits snugly to the spindle and mountings. If I bought an of the shelf pot then
I'd have to fiddle around trying to get it mounted properly 
Why they used a log pot I have no idea, but I've carefully measured the output and it's definitely log!
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RazMan
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| posted on 5/9/06 at 07:51 AM |
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Agreed - the electronics involved in converting the output would be a lot of hassle. Just change the pot. 
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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iank
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| posted on 5/9/06 at 07:59 AM |
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Are you sure you want linear on the throttle pot?
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matt_claydon
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| posted on 5/9/06 at 08:19 AM |
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Forget this, I've been a muppet and wired the pot up wrong giving what looked like a log output (had the wiper and ground switched). Swapped
round now and its nice and linear.
Annoying thing is I thought it might be that before and swear I checked three days ago but must just have been having a severe attack of incompetence
I think maybe I'll blame the voltmeter.
[Edited on 5/9/06 by matt_claydon]
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