Author Topic: Converting Wheelchair controller to hand throttle  (Read 1262 times)

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Offline catch22Topic starter

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Converting Wheelchair controller to hand throttle
« on: December 18, 2010, 07:31:43 PM »
Hi.  I am new to this board and a novice when it comes to DC systems.  I am building a small wood car.  I have purchased a set of 24V wheelchair motors with the controller and throttle.  This is a joystick system.  I am planning to change this to a twist throttle and set this up as a pedal throttle.  The controller is a Penny & Giles.  The joystick has 4 wires. 

I want to use reverse for the car.  In the wheelchair, you would just go backwards on the joystick to get the unit to go backwards.  I know I will need to add a switch to activate the reverse.  In looking at schematics for the P&G.  It shows the red wire as the reverse. 

Can someone give me assistance in how to hook up the reverse so that I can run it off the hand throttle. The hand throttles come with three and 4 wires.


Offline Soeren

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Re: Converting Wheelchair controller to hand throttle
« Reply #1 on: December 21, 2010, 02:47:20 AM »
Hi,

For starters, post all the wiring diagrams that you have.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline catch22Topic starter

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Re: Converting Wheelchair controller to hand throttle
« Reply #2 on: December 29, 2013, 06:10:46 PM »
Well, I set that project aside for a few years, but am back at it again.  I have a older sunrise healthcare 2 Fracmo motor unit with a Penny & Giles. controller.  Controller has a 5 wire (black, red, yellow, green, blue) PWL joystick and I want to convert this to a twist grip controller.

This unit will power a childs scale model car, so it needs only to go forward and have a switch to go backward.   Twist controller has 4 wires.  Black, Green, Red, Yellow.   

I tried for a number of months to get a wiring diagram for the P/G controller, but the company could not find one for this old a unit. 

I am open to any thoughts and even changing to a different controller if needed. 

I have added pictures of the unit, the pin connector for the joy stick, the wires for the twist controller and the motor.  The plate on the motor and controller are very scratched/faded but I can probably do a transfer of the information off the motor if that would help.


Offline jwatte

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Re: Converting Wheelchair controller to hand throttle
« Reply #3 on: December 29, 2013, 06:58:58 PM »
So, if you want to change out the joystick, I suggest you should focus on replacing the joystick, and providing wiring diagrams of the joystick.

My guess is that the joystick has one common terminal, and four direction terminals (wires.) You should be able to figure out which ones change, and how, when you move the joystick, using a multimeter.

Once you have figured out how the joystick is wired/connected, it should be reasonably simple to provide another control that behaves in the same way, at least for the forward/backward direction.

Offline Tommy

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Re: Converting Wheelchair controller to hand throttle
« Reply #4 on: December 30, 2013, 07:11:16 AM »
Quote
I am open to any thoughts and even changing to a different controller if needed. 

catch22, while it possible to use the P&G controller, it's far easier to use something like a sabertooth
http://www.dimensionengineering.com/products/sabertooth2x60

with P&G controller you'd need a special manufacture supplied device to change things like acc/dec and
speed profiles, with controllers like the sabertooth they can be set using your pc.

Tommy
 
   

Offline catch22Topic starter

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Re: Converting Wheelchair controller to hand throttle
« Reply #5 on: December 30, 2013, 07:20:47 PM »
Thanks Tommy


I have been reading some of the posts on the sabertooth and that is a consideration.  As this is a scale model car, I was hoping to keep the costs down.  But that is something I have been considering.

Jwatte.  That sounds like something I can do.  I could not find anything on this joystick, but I have seen some diagrams that discuss what wires do what.  I will work on seeing if I can figure out what does what.

Bruce.

Offline Tommy

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Re: Converting Wheelchair controller to hand throttle
« Reply #6 on: December 31, 2013, 05:47:38 AM »
Quote
I was hoping to keep the costs down.
catch22, I have used the P&G speed controller for an application, and like you was faced with
very little manufacturer's support or searchable documentation, but with a volt meter I was able
to measure the values on the wires for the joystick(while under normal power on conditions), it
turned out to only need two analog voltages, one for speed and one for direction.

these two analog voltages ranged between 1Vdc(max speed reverse) to 4Vdc(max speed forwards)
and 2.5Vdc as motor stopped, if the analog voltage went under 1Vdc or over 4Vdc the speed controller
would go into a fault mode(disabling the drive), also if the controller was turned on without both analog
voltages at 2.5Vdc the controller would fault out. these safety features plus the controllers plug & play
electric motor brake control makes it an attractive option(until the controller has a problem).

to keep costs down you should be able to get by with a sabertooth 2x25 as a speed controller.

Tommy   

 

 


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