[samseide]

Well I won an ebay auction and now I have two wheelchair motors coming my way. yay!

I'm trying to build a people mover chair, like this:

but am unsure of the electronics. The way I see it, I'd like the switches to be behind the chair where someone could switch it on or off from there. I know I'd need two 12v batteries to run the motors as they're 24v motors, but I'm unsure if I would need a relay or just a switch to go between the motors and the battery. I just want a way to turn the motors on and off, not control speed or anything. Just trying to be safe and don't know what the best way to do that would be. Also, can't figure out how to wire a switch with a relay in my particular situation as the only stuff I seem to be able to find online talk about using relays to connect stuff to car/motorcycle ignitions.

I attached some pics of the motors I won.

 

[jdsteel82]

Definitely a Relay! Those wheel chair motors can draw some amps, and most switches will weld or blow up.

 

[samseide]

so when you use a relay for this instance...you hook up the positive wires coming from the big battery to the relay and then down to the motor off the relay, and hook the two wires attached to the switch to the relay? I've tried to understand relays but I'm just not grasping the concept of how they're wired up. I know the switch has to get power from somewhere but I don't know where in the wiring you would put the power to the switch or even how much power you have to give it.

 

[jdsteel82]

You pretty much got it. it should look like this
BATT +------Sw_in Sw_out----Relay coil_in Relay coil_out----BATT -Neg

Batt+-----Relay Pole
BATT -Neg---Motor_in Motor_out---Relay Normaly open throw.


I hope that helps, and doesnt make it even more confusing.

 

[pagan]

Otaku had a good explanation of relays posted here last year..

 

[samseide]

I think I found the otaku relay explanation:

http://www.hauntforum.com/showthread.php?t=10973&highlight=relay

is this the one you were talking about?

It offers up quite a bit of relay knowledge, but how do I know how much power I need on the switch side in order to switch on the motor side of the relay?

 

[bourno]

Thought over at modifiedpowerwheels.com forum may had a decent wiring diagram. Found this one. Ignore the "Bulb" part. The switch doesn't need to source much, under an amp for the relay coil. From the relay wire 87, it would go to the motor and the other motor wire would go the battery negative

 

[samseide]

that's exactly what I was looking for! haha! I'm a visual learner.

 

[jdsteel82]

that is exactly what I was trying to explain....much better in pictures!

 

[DarkLore]

...I'm a visual learner.

I illustrated the use of relays in the sticky found at the top of the Tech Terror forum (Use of Prop Controllers).

 

[Dead Things]

Power wheelchairs have 4 main components: power source (batteries), propulsion (motors), controller (computer) and activator (joystick/switches). The joystick/switches are kind of like a mouse is to a computer, it directs the action but without the controller, the joystick/switch is useless. If you have all the electronics, great, hook it up and away you go. Some of the older style power (from the 70's to early 90's) had the controller and joystick combined, newer models are seperate to allow for different types of driver controls.

 

[samseide]

I have the two motors and the wheels. The motors have the wires coming out of them, a thick red and black I'm assuming are positive and ground and a yellow and white wire. I've read that wheelchair motors have some sort of powered brake in the motor, where if the brake is not given a voltage, it is engaged, so that it keeps the wheelchair still when power isn't applied. Not sure if that's what the yellow and white wires are or not. I didn't get the controller or the batteries or the joysticks, though if I just want to have them either all on or all off, I'm hoping that isn't a problem (course I'll still have to go buy batteries. ha.)

 

[samseide]

also, darklore, that is the most concise and wonderful introduction to relays I've seen on the web! And trust me...I've been looking for one for quite awhile! ha! Thanks for that great post!

 

[Dead Things]

Wanted to make sure I had this correct before I posted this. According to my supplier, the 4 wires are as follows, red and black are + and -, the two other wires are + and - for the brake release. I thought one of them might be for reversing polarity b ut was told that occurs within the controller. Hope this helps. If you have any more questions, I'll try to get answers out of my supplier.

 

[samseide]

Yes the ends of the motors are just rubber slip on pieces and there are what appears to be large silver pieces of metal at the end of the motor where the yellow and white wire go to. I'm debating whether or not to try to take those off the motors. Seems like a waste of battery power to send power to an emergency brake when I don't really plan on having this thing be on type of inclined terrain where I would need it to shut down and hold the motor still if it loses power.

 

[Dead Things]

actually I don't think those are wheelchair motors, those are scooter motors. On wheelchair motors, the bolts section for the wheels would be at right angle to the main body of the motor. Semantics really, the function is the same. You may not be able to disconnect the brake release. I would try hooking up the batteries and see what ticks, literally. When the brake releases there is a click. Will try and get more info next week.

 

[bourno]

They look like wheel chair motors to me.

 

[Dead Things]

I'm not saying they aren't, older models may have had the hub configured in that way. Most chairs I deal with are no more than 10 years old.