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Discussion Starter · #1 ·
I must be missing something...

How do you turn a potentiometer through its normal 270 degrees of rotation
with an accelerator cable connected to a lever on the pot's shaft?

Thank you,

Dave Delman
1981 Electric DeLorean Project



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Discussion Starter · #2 ·
Hello Dave,

Check your controller data to see how much ohms range you need with a
potentiometer. Normally these are from 0 to 5000 ohms. A Curtis pot box
only needs to turn 90 degrees for a reading of 0 to 5000 ohms. My
controller does not start turning the motor until the potentiometer is at
about 50 ohms of where I set it for a soft start.

If you want a violent start, then set it at the point where you barely press
the accelerator. This is not recommended as where if the ohms do not go
below the start up point, the motor may not shut down.

Roland


----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Monday, September 03, 2007 8:22 AM
Subject: [EVDL] Pot Box


> I must be missing something...
>
> How do you turn a potentiometer through its normal 270 degrees of rotation
> with an accelerator cable connected to a lever on the pot's shaft?
>
> Thank you,
>
> Dave Delman
> 1981 Electric DeLorean Project
>
>
>
> ************************************** Get a sneak peek of the all-new AOL
> at
> http://discover.aol.com/memed/aolcom30tour
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

_______________________________________________
For subscription options, see
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Discussion Starter · #3 ·
Dave Delman wrote:
> How do you turn a potentiometer through its normal 270 degrees of rotation
> with an accelerator cable connected to a lever on the pot's shaft?

You either have a mechanical linkage that rotates the pot 270 degrees when the accelerator pedal moves from top to bottom. Or, you use a pot that goes from 0-5k ohms with only (say) 90 degrees of rotation (whatever is convenient for your car's throttle linkage).

The Curtis potbox takes the latter approach. They use a custom potentiometer that only needs90 degrees of rotation to go from 0 to 5k ohms of resistance. You can accomplish the same thing by using a regular 20k pot, and not using the parts of the rotation past 5k.

--
"Excellence does not require perfection." -- Henry James
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Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

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Discussion Starter · #5 ·
I can think of a few ways, but it is probably easier just to get the
right pot.

An idler that when turned 90 degrees has a 2" diameter drum pulling
1.57" of cable. This is wrapped around a 5/8" drum.

It may be simpler if you have a throttle cable. Measure the cable pull
length. Maybe change the leverage at the pedal to pull more cable then
wrap it around the appropriate sized drum.

or a 3:1 gear reduction, or chain. I use to have the perfect type of
stuff in my junk drawer from copier parts. A hobby shop may be the
answer (think battle bot hardware and RC car chain and sprocket.)

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