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  #61  
Old 08-30-2010, 11:55 AM
EVDL List EVDL List is offline
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Default Re: [EVDL] Jumpy Pots

My third pot from Kelly is now failing. It's an enclosed foot pedal and the
pot is a sealed Hoss WDJ 22 and doesn't feel like a cheapo, but three of
them have failed within less than a month each. The spec sheet I found
seems to show values of rotation from 20K to 100K cycles, but that's not
much in automotive use considering how often a throttle is moved during a
drive. Automotive pots seem to list millions of cycles, I just can't seem
to find one with a male shaft that will fit inside the Kelly pedal assembly.


[quote]Tom H wrote:
>
> Hello to another Tom,
>
> Sorry to be so late in responding, but I just got back from vacation.
>
> I found that the Chinese copy of the PB-6 that is available from several
> vendors has worked out better than the PB-6. I also tried the
> replacement pot that is sold by EV-parts, but that proved to be bad from
> the beginning. The discussion around my first comments suggested that
> the issue was dirt getting into the box. I taped my Chinese copy around
> all the open edges and that seems to have improved the situation. My
> Chinese copy has now been installed for over a year without any
> problems. However, I do suspect that it may go soon. It is showing
> some instability when the outside temperature goes above 90 degrees.
>
>
>
> My Logisystems controller blew out for the second time and so I am now
> switching and will try the NetGain controller that has the Hall effect
> throttle. I hope that works out better.
>
>
>
> Tom
>
>
>
> From: tomw [via Electric Vehicle Discussion List]
> [mailto:ml-node+xxx@xxx.xxxle.com]
> Sent: Sunday, August 22, 2010 6:21 PM
> To: Hruby, Tom (ECY)
> Subject: Re: Jumpy Pots
>
>
>
> This post by Tom exactly describes the symptoms my PB6 is displaying.
> It started a few weeks ago and is getting worse. The car has about 8
> months on it, same as when Tom's started acting up. Anyone found a
> better solution than the PB6? The controller is a Curtis 1238-7501.
>
> ________________________________
>
> View message @
> http://electric-vehicle-discussion-list.413529.n4.nabble.com/Jumpy-Pots-
> tp462965p2334529.html
> To unsubscribe from Jumpy Pots, click here
> <http://electric-vehicle-discussion-list.413529.n4.nabble.com/template/N
> odeServlet.jtp?tpl=unsubscribe_by_code&node=462965 &code=dGhydTQ2MUBlY3ku
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>
>
>
>
>

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  #62  
Old 08-30-2010, 07:35 PM
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Default Re: [EVDL] Jumpy Pots

Hi Tom,

Yes, I've heard dust suspected as the cause, but mine is inside an aluminum
box, and the inside of the box appears clean. Could still be the cause if
it only takes a very small amount of dust I suppose. I can install the
EVWorks Hall throttle fairly easily it turns out. The controller has 5V and
ground outputs as well as the throttle input. I just have to switch two
wires and add one. The throttle pot will mount right in place of the PB6.
That way I shouldn't have to replace the throttle every year or two. As
JRP3 says even 100k cycles isn't all that much considering all the small
adjustments you are continuously making with the throttle for grade
changes, slowing/speeding up in traffic, changing speed limits,
stopping/starting... I do a lot of driving at about the same speed so that
part of the throttle gets a lot of use, and that is where the throttle is
jumpy. I should receive the Hall throttle in a few days or so.
--
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  #63  
Old 08-30-2010, 09:16 PM
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Default Re: [EVDL] Jumpy Pots

Has anybody ever tried one of these arcade game controllers?

http://www.happcontrols.com/driving/50819400.htm

I'm considering getting it for my electric rider mower. The price is mighty
reasonable, and one would hope that a pedal made for arcade use would be
pretty durable.

David Roden - Akron, Ohio, USA
EVDL Administrator

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  #64  
Old 08-30-2010, 09:57 PM
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Default Re: [EVDL] Jumpy Pots

*David, That is a difficult question to answer. Back in 1979, I was a video
game service tech. for Champeen (sic) Electronics and we repaired the big
consoles 6 ft tall, 2 ft wide, and 3 ft deep in a big plywood box. I built
one into a special case to hold a 60 in. monitor that was the "Showcase " of
the Arcade who bought it. Funny because it only ran "Asteroids" a monochrome
game. To your point the only pedals that lasted had a small incandescent
lamp running on 2/3 of rated voltage for longer life and a CdS photo cell
that provided varying resistance as light level changed, and a wire link
moved a moving vane between the lamp and the CdS cell as the pedal was
pressed about 2 inches the vane moved 1/4 inch These lasted for ever.
Everything else wore out after two years or less, I know, I replaced pots
and micro-switches constantly. My dream EV would use a slotted vane moving
between two led and two photo transistor and a up/down counter like a mouse
to drive a D to A conversion ladder that would be cheep and have no wear
parts. And more linear than a hall effect device. add a third led and photo
transistor to kick the counter to zero when the pedal is all the way up for
calibration.
Regards,
Dennis Lee Miles (Director) E.V.T.I. inc.
www.E-V-T-I-Inc.COM (Adviser) EVTI-EVA Education Chapter
Phone (863) 944 - 9913*
-------------------------------------------------------------------------------------------------------------------
[quote] EVDL Administrator <xxx@xxx.xxx>wrote:

> Has anybody ever tried one of these arcade game controllers?
>
> http://www.happcontrols.com/driving/50819400.htm
>
> I'm considering getting it for my electric rider mower. The price is
> mighty
> reasonable, and one would hope that a pedal made for arcade use would be
> pretty durable.
>
> David Roden - Akron, Ohio, USA
> EVDL Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> EVDL Information: http://www.evdl.org/help/
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> Note: mail sent to "evpost" an "etpost" addresses will not
> reach me. To send a private message, please obtain my
> email address from the webpage http://www.evdl.org/help/ .
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
>
>
> _______________________________________________
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  #65  
Old 06-27-2012, 01:15 PM
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Default Re: [EVDL] jumpy Pots

OK, found the old thread with the pot suggestion from Lee,
besides the obvious to go to pick-n-pull and get a TPS
(Throttle Position Sensor) from one of the cars that has
drive by wire (which is essentially all modern cars).
My car also accepts a 0 to 3.5V input instead of the
accelerator potmeter, so I can make things work even if they
are not 0-5kOhm...

I noticed an old request from someone to convert a 0 - 5V
signal to a 0 - 5kOhm resistance. That should be simple and
only require an opamp and two identical MOSFETs. Send a
fixed 1mA current through one and compare with the input
voltage. The other represents the 0 - 5kOhm output based on
the 0-5V input.
In case it needs to be 5k - 0 or other conversions
(for example from a too sensitive linear pot to logarithmic,
which will allow smooth take-off) then that is possible also.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: xxx@xxx.xxx Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203

-----Original Message-----
From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
Behalf Of Lee Hart
Sent: Tuesday, September 29, 2009 9:04 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] jumpy Pots

[quote]Electric Blue auto convertions wrote:
> I have only had 3 pots go bad so far and they were with in the first
> year. NOW if you see what Fork lifts use, the same thing only built
> much better and are still 5K ohm they last forever, BUT if you call
> Hyster, Cat, or Clark they want between 50 and 70 $ for the pot
> itself, is it worth it> thats up to you ..Wayne ev-blue.com

Try MIL style RV4. There are many manufacturers (like the Allen Bradley
type AB I mentioned, though Allen Bradley seems to have sold their pot
business to someone, so it's under a new name). Here's an example from
Digikey:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=RV4N253
C-ND
http://www.precisionelectronics.com/MIL%20Style%20RV4%20PDF%20Download_f
iles/MIL%20Style%20RV4.pdf

Sealed, gold plated terminals, stainless steel shaft, 25,000 cycle
rotational life, about $8.
--
Lee A. Hart | Ring the bells that still can ring
814 8th Ave N | Forget the perfect offering
Sartell MN 56377 | There is a crack in everything
leeahart earthlink.net | That's how the light gets in -- Leonard Cohen

_______________________________________________
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http://evdl.org/help/index.html#conv
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| Please take those discussions elsewhere. Thanks.
|
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  #66  
Old 06-27-2012, 11:55 PM
EVDL List EVDL List is offline
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Default Re: [EVDL] jumpy Pots

When ordering the pot, be very careful to determine the length of the shaft
and make sure it's compatible with the pot already in the potbox. My first
try, I got a pot that looked compatible, but the shaft was too short to fit
correctly into the lever arm.

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Cor van de Water
> Sent: Wednesday, June 27, 2012 1:01 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
> OK, found the old thread with the pot suggestion from Lee, besides the
> obvious to go to pick-n-pull and get a TPS (Throttle Position Sensor) from
one
> of the cars that has drive by wire (which is essentially all modern cars).
> My car also accepts a 0 to 3.5V input instead of the accelerator potmeter,
so I
> can make things work even if they are not 0-5kOhm...
>
> I noticed an old request from someone to convert a 0 - 5V signal to a 0 -
> 5kOhm resistance. That should be simple and only require an opamp and two
> identical MOSFETs. Send a fixed 1mA current through one and compare with
> the input voltage. The other represents the 0 - 5kOhm output based on the
> 0-5V input.
> In case it needs to be 5k - 0 or other conversions (for example from a too
> sensitive linear pot to logarithmic, which will allow smooth take-off)
then
> that is possible also.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: xxx@xxx.xxx Private: http://www.cvandewater.com
> Skype: cor_van_de_water XoIP: +31877841130
> Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203
>
> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Lee Hart
> Sent: Tuesday, September 29, 2009 9:04 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
[quote]> Electric Blue auto convertions wrote:
> > I have only had 3 pots go bad so far and they were with in the first
> > year. NOW if you see what Fork lifts use, the same thing only built
> > much better and are still 5K ohm they last forever, BUT if you call
> > Hyster, Cat, or Clark they want between 50 and 70 $ for the pot
> > itself, is it worth it> thats up to you ..Wayne ev-blue.com
>
> Try MIL style RV4. There are many manufacturers (like the Allen Bradley
type
> AB I mentioned, though Allen Bradley seems to have sold their pot business
> to someone, so it's under a new name). Here's an example from
> Digikey:
>
> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=RV4N25
> 3
> C-ND
> http://www.precisionelectronics.com/MIL%20Style%20RV4%20PDF%20Dow
> nload_f
> iles/MIL%20Style%20RV4.pdf
>
> Sealed, gold plated terminals, stainless steel shaft, 25,000 cycle
rotational life,
> about $8.
> --
> Lee A. Hart | Ring the bells that still can ring
> 814 8th Ave N | Forget the perfect offering
> Sartell MN 56377 | There is a crack in everything
> leeahart earthlink.net | That's how the light gets in -- Leonard
Cohen
>
> _______________________________________________
> General EVDL support: http://evdl.org/help/ Usage guidelines:
> http://evdl.org/help/index.html#conv
> Archives: http://evdl.org/archive/
> Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
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  #67  
Old 06-28-2012, 12:35 AM
EVDL List EVDL List is offline
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Join Date: Jul 2007
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Default Re: [EVDL] jumpy Pots

My setup is not a standard potbox anyway.
It has the pot mounted in a bracket and on its shaft
is a metal piece with a set screw and a U-shaped hole.
In that hole sits a pin which can slide left and right
on another shaft. Next to that is also a metal block
which pushes the microswitch as soon as entire thing
starts sliding.
That contraption is not directly operated by the cable
from the pedal, but instead a lever is mounted where the
cable pulls on one end and the other end operates this
contraption, which also has return spring built-in.
It is a very universal and clever mechanical design,
but if you look at modern TPS assemblies attached to
the pedal itself, then you wonder why we make some
things so complex.
Same here - the whole deal with the microswitch selecting
between idle run and the pot, causing the controller to
throw errors when the input voltage goes over 3.7 during
the switch...
I was thinking about the whole deal and decided that the
simples solution is to send more current through the pot.
The upper 1.2 or 1.5kOhm is working well (little use) so
if I just increase the current by 2mA then the 3.6V to 0
range is the upper half of the pot.
To avoid that the input voltage goes too high and to
get a stable idle RPM, I will simply add a so-called
programmable zener like a TL431 and re-purpose the already
present trimpot and series resistor as the 2.5V divider
for the zener. This means that I can solder the TL431 on
that combination, add a pull-up resistor to send 2mA more
into the pot, remove the microswitch wires and simply
wire the zener in parallel to the pot and I am done.
I like it whem solutions are simple.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: xxx@xxx.xxx Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203

-----Original Message-----
From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
Behalf Of Mike Nickerson
Sent: Wednesday, June 27, 2012 10:39 PM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] jumpy Pots

When ordering the pot, be very careful to determine the length of the
shaft and make sure it's compatible with the pot already in the potbox.
My first try, I got a pot that looked compatible, but the shaft was too
short to fit correctly into the lever arm.

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Cor van de Water
> Sent: Wednesday, June 27, 2012 1:01 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
> OK, found the old thread with the pot suggestion from Lee, besides the

> obvious to go to pick-n-pull and get a TPS (Throttle Position Sensor)
> from
one
> of the cars that has drive by wire (which is essentially all modern
cars).
> My car also accepts a 0 to 3.5V input instead of the accelerator
> potmeter,
so I
> can make things work even if they are not 0-5kOhm...
>
> I noticed an old request from someone to convert a 0 - 5V signal to a
> 0 - 5kOhm resistance. That should be simple and only require an opamp
> and two identical MOSFETs. Send a fixed 1mA current through one and
> compare with the input voltage. The other represents the 0 - 5kOhm
> output based on the 0-5V input.
> In case it needs to be 5k - 0 or other conversions (for example from a

> too sensitive linear pot to logarithmic, which will allow smooth
> take-off)
then
> that is possible also.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: xxx@xxx.xxx Private: http://www.cvandewater.com
> Skype: cor_van_de_water XoIP: +31877841130
> Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203
>
> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Lee Hart
> Sent: Tuesday, September 29, 2009 9:04 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
[quote]> Electric Blue auto convertions wrote:
> > I have only had 3 pots go bad so far and they were with in the first

> > year. NOW if you see what Fork lifts use, the same thing only built
> > much better and are still 5K ohm they last forever, BUT if you call
> > Hyster, Cat, or Clark they want between 50 and 70 $ for the pot
> > itself, is it worth it> thats up to you ..Wayne ev-blue.com
>
> Try MIL style RV4. There are many manufacturers (like the Allen
> Bradley
type
> AB I mentioned, though Allen Bradley seems to have sold their pot
> business to someone, so it's under a new name). Here's an example from
> Digikey:
>
> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=RV4N2
> 5
> 3
> C-ND
> http://www.precisionelectronics.com/MIL%20Style%20RV4%20PDF%20Dow
> nload_f
> iles/MIL%20Style%20RV4.pdf
>
> Sealed, gold plated terminals, stainless steel shaft, 25,000 cycle
rotational life,
> about $8.
> --
> Lee A. Hart | Ring the bells that still can ring
> 814 8th Ave N | Forget the perfect offering
> Sartell MN 56377 | There is a crack in everything
> leeahart earthlink.net | That's how the light gets in --
Leonard
Cohen
>
> _______________________________________________
> General EVDL support: http://evdl.org/help/ Usage guidelines:
> http://evdl.org/help/index.html#conv
> Archives: http://evdl.org/archive/
> Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev
>
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to xxx@xxx.xxx.edu only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
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_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
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Reply With Quote
  #68  
Old 06-28-2012, 07:55 AM
EVDL List EVDL List is offline
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Join Date: Jul 2007
Posts: 70
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Default Re: [EVDL] jumpy Pots

Cor,
Perhaps you should draw something up and post it (you could use the free
schematic/layout
program www.expresspcb.com for example). Sometimes my attention span is not
very good when reading a description without a schematic where I can visualize
it immediately.
I does sound like this will work since the program just looks for an accelerator
input of less than 2.5V
when the start switch is open (indicating there is a problem since the start
switch is open and it appears
as if the accel is pressed,)
LDA ACC_AD ;ACC<2.5V
CMP #80H
BHI S_CKA
STPEN: BRCLR 0,PORTA,FR_T ;1=ST OPEN
LDA #05H ;FLT 5

Here's the situation I believe your seeing, FLT 7 when voltage is too high
(above 3.7V)
CA_T: LDA ACC_AD
CMP #0BDH ;3.7V,189
BLS IATT
BSET 3,AFLAG
BRSET 7,EFLAG,IAT ;1=TMM FLT
LDA #07H ;FLT 7,ACC>3.7
BSET 1,BFLAG ;FLT FLAG
JSR DISP




----- Original Message ----
From: Cor van de Water <xxx@xxx.xxx>
To: Electric Vehicle Discussion List <xxx@xxx.xxx.edu>
Sent: Thu, June 28, 2012 2:31:50 AM
Subject: Re: [EVDL] jumpy Pots

My setup is not a standard potbox anyway.
It has the pot mounted in a bracket and on its shaft
is a metal piece with a set screw and a U-shaped hole.
In that hole sits a pin which can slide left and right
on another shaft. Next to that is also a metal block
which pushes the microswitch as soon as entire thing
starts sliding.
That contraption is not directly operated by the cable
from the pedal, but instead a lever is mounted where the
cable pulls on one end and the other end operates this
contraption, which also has return spring built-in.
It is a very universal and clever mechanical design,
but if you look at modern TPS assemblies attached to
the pedal itself, then you wonder why we make some
things so complex.
Same here - the whole deal with the microswitch selecting
between idle run and the pot, causing the controller to
throw errors when the input voltage goes over 3.7 during
the switch...
I was thinking about the whole deal and decided that the
simples solution is to send more current through the pot.
The upper 1.2 or 1.5kOhm is working well (little use) so
if I just increase the current by 2mA then the 3.6V to 0
range is the upper half of the pot.
To avoid that the input voltage goes too high and to
get a stable idle RPM, I will simply add a so-called
programmable zener like a TL431 and re-purpose the already
present trimpot and series resistor as the 2.5V divider
for the zener. This means that I can solder the TL431 on
that combination, add a pull-up resistor to send 2mA more
into the pot, remove the microswitch wires and simply
wire the zener in parallel to the pot and I am done.
I like it whem solutions are simple.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: xxx@xxx.xxx Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203

-----Original Message-----
From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
Behalf Of Mike Nickerson
Sent: Wednesday, June 27, 2012 10:39 PM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] jumpy Pots

When ordering the pot, be very careful to determine the length of the
shaft and make sure it's compatible with the pot already in the potbox.
My first try, I got a pot that looked compatible, but the shaft was too
short to fit correctly into the lever arm.

Mike

> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Cor van de Water
> Sent: Wednesday, June 27, 2012 1:01 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
> OK, found the old thread with the pot suggestion from Lee, besides the

> obvious to go to pick-n-pull and get a TPS (Throttle Position Sensor)
> from
one
> of the cars that has drive by wire (which is essentially all modern
cars).
> My car also accepts a 0 to 3.5V input instead of the accelerator
> potmeter,
so I
> can make things work even if they are not 0-5kOhm...
>
> I noticed an old request from someone to convert a 0 - 5V signal to a
> 0 - 5kOhm resistance. That should be simple and only require an opamp
> and two identical MOSFETs. Send a fixed 1mA current through one and
> compare with the input voltage. The other represents the 0 - 5kOhm
> output based on the 0-5V input.
> In case it needs to be 5k - 0 or other conversions (for example from a

> too sensitive linear pot to logarithmic, which will allow smooth
> take-off)
then
> that is possible also.
>
> Cor van de Water
> Chief Scientist
> Proxim Wireless Corporation http://www.proxim.com
> Email: xxx@xxx.xxx Private: http://www.cvandewater.com
> Skype: cor_van_de_water XoIP: +31877841130
> Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203
>
> -----Original Message-----
> From: xxx@xxx.xxx.edu [mailto:xxx@xxx.xxx.edu] On
> Behalf Of Lee Hart
> Sent: Tuesday, September 29, 2009 9:04 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] jumpy Pots
>
[quote]> Electric Blue auto convertions wrote:
> > I have only had 3 pots go bad so far and they were with in the first

> > year. NOW if you see what Fork lifts use, the same thing only built
> > much better and are still 5K ohm they last forever, BUT if you call
> > Hyster, Cat, or Clark they want between 50 and 70 $ for the pot
> > itself, is it worth it> thats up to you ..Wayne ev-blue.com
>
> Try MIL style RV4. There are many manufacturers (like the Allen
> Bradley
type
> AB I mentioned, though Allen Bradley seems to have sold their pot
> business to someone, so it's under a new name). Here's an example from
> Digikey:
>
> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=RV4N2
> 5
> 3
> C-ND
> http://www.precisionelectronics.com/MIL%20Style%20RV4%20PDF%20Dow
> nload_f
> iles/MIL%20Style%20RV4.pdf
>
> Sealed, gold plated terminals, stainless steel shaft, 25,000 cycle
rotational life,
> about $8.
> --
> Lee A. Hart | Ring the bells that still can ring
> 814 8th Ave N | Forget the perfect offering
> Sartell MN 56377 | There is a crack in everything
> leeahart earthlink.net | That's how the light gets in --
Leonard
Cohen
>
> _______________________________________________
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>
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  #69  
Old 06-28-2012, 12:26 PM
EVDL List EVDL List is offline
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Default Re: [EVDL] jumpy Pots

I don't see why it is so hard to have a pot go from 0 to 100 ohms on the first
half of the throw and 100 to 5000 ohms on the second half. It's the way a gas
engine works. Electric has no lag therefore it's jerky. I have a standard
Curtis pot and it is tricky to start. My daughter won't even drive it. I'd
love to find a specialized pot. Maybe a series of pots in parallel or series.
I start my ev in first gear and leave it there until I get to 25mph. Once
started and rolling no problem. It's overcoming the start with just the right
push that is tricky. Worst case my car bucks like a bucking bronco. Lawrence
Rhodes....but it is possible but takes about 5 seconds to do smoothly.

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| Please take those discussions elsewhere. Thanks.
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  #70  
Old 06-28-2012, 12:45 PM
EVDL List EVDL List is offline
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Default Re: [EVDL] jumpy Pots

Some controllers have that feature built in. For example, you can set what percentage PWM half-throttle is. If you set it to, say, 30%, then the first half of the throttle is 0% - 30%, and the second half of the throttle is 30% - 100%.

Bill

----- Original Message -----
From: Lawrence Rhodes <xxx@xxx.xxx>
To: xxx@xxx.xxx.edu
Sent: Thu, 28 Jun 2012 14:16:46 -0400 (EDT)
Subject: Re: [EVDL] jumpy Pots

I don't see why it is so hard to have a pot go from 0 to 100 ohms on the first
half of the throw and 100 to 5000 ohms on the second half. It's the way a gas
engine works. Electric has no lag therefore it's jerky. I have a standard
Curtis pot and it is tricky to start. My daughter won't even drive it. I'd
love to find a specialized pot. Maybe a series of pots in parallel or series.
I start my ev in first gear and leave it there until I get to 25mph. Once
started and rolling no problem. It's overcoming the start with just the right
push that is tricky. Worst case my car bucks like a bucking bronco. Lawrence
Rhodes....but it is possible but takes about 5 seconds to do smoothly.

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to xxx@xxx.xxx.edu only.
| Multiple-address or CCed messages may be rejected.
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| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev

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