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Projects => Tech Help - Projects Page => Topic started by: mikeny on April 19, 2013, 02:22:35 PM

Title: Need help with modifying pot throttle's value using resistors
Post by: mikeny on April 19, 2013, 02:22:35 PM
Hey guys. I looking for some help with a 3 wire pot throttle for a e-scooter. Below is what I have and what I'm looking for achieve.
The pot throttle has a 10K pot in it. It has a red, a black and a green wire.
Two of wires' resistance measured at about 0-4K ohms
the other wires' resistance measured at about 6-10k
so, the motor either spins right up or it doesn't go to it's max speed when the throttle is connected.
Is there a way to modify it so that it will cover the full range of 0-10K in the same rotation range?
Thanks in advance.
Title: Re: Need help with modifying pot throttle's value using resistors
Post by: stecykmi on April 19, 2013, 11:21:09 PM
i don't think it's possible to both increase a pot's resistance and keep a minimum resistance value of 0.

you can only increase resistance by putting a resistor in series, but this means the minimum resistance will be the value of the resistor itself.

putting a resistor in parallel will allow for a minimum resistance of zero, but by definition this can only decrease the total resistance.

you'll have to swap the pot for something with a more suitable resistance. you can then try playing with this calculator to obtain the correct resistance: http://www.diystompboxes.com/analogalchemy/emh/emh.html
Title: Re: Need help with modifying pot throttle's value using resistors
Post by: stecykmi on April 19, 2013, 11:31:56 PM
additionally, if you measured these values without disconnecting the pot, you probably won't get accurate measurements.
Title: Re: Need help with modifying pot throttle's value using resistors
Post by: mikeny on April 19, 2013, 11:49:25 PM
The pot was disconnected when it was measured.
I've been trying to find a different pot but unsuccessful. The throttle uses a sealed pot. Very small in size. The throttle is not using full range of the current pot that's why it's at 0-4K. I might just seek other alternatives. I will try the calculator. Thanks.