So I've bought all the parts for my twin 400w kollmorgen electric bicycle project. I've received the motors but the rest of the parts are on the way. Aside from a new rear wheel to mount on the front fork (fwd) the only thing I did not purchase was a throttle. I need to run both motors evenly but both require a 5k pot.
1) Can I run two of these motors(controllers) off a single 5k pot?
2) If not does anyone know of a source to find a dual 5k pot(six wires, two pots connected on a single shaft)?
3) Will a pot with ohms over 5k work?
4) The professor at the college's electronic department, I go to, told me about voltage controlled pots for a more accurate equalization of both motors. Does anyone know where to purchase them? I stumped the guy at radio shack with this and all these questions, it was funny.
I've used this site A LOT while researching how I was going to go about building my bike and my plan actually evolved two or three times for the better because of you guys. This is my first actual post on the forum but not the last. Thanks. -Ryan
Yeah, you can.
I've seen dual linear 5k pots, but only as a part; I've never seen a dual 5k throttle.
Three wire pot throttles typically work as voltage dividers. With suitable current and voltage levels coming from the controller, any pot would work. However, since the current from the Kollmorgen controller's throttle out is limited, higher than 5k wacks out the throttle response. Less than 5k and more voltage from the + throttle lead gets leaked into the ground of the lead, meaning you won't ever be able to go full throttle. In short, only a 5kΩ 3 wire resistive throttle will work on a Kollmorgen without modification.
DigiKey probably has them (they have like everything), but that's overkill. Since the Kollmorgens are designed to work properly with a 5% tolerance on the throttle, it shouldn't make any difference in the throttle response.
To actually run them off one throttle is simple: Hook the throttle up to one motor as you would normally, and connect an extra signal wire to the second controller. Note that while this should work in theory, I have not tried this. If you want I have four Kollmorgens lying around doing nothing. I could try it out if you want.
Welcome, BTW. :)
The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai
I have two brand-new Kollmorgens and am interested in putting dual motors on a scooter. Was hoping to hook them to one common 5K throttle, but unsure of the wiring. So, if you'd be willing to do a quick test, there's likely at least two of us that would be interested in the results. Thanks.
Harlow
*"digipot" not "voltage controlled pot" is what the teacher meant, I think*
Thanks for the test work. I would try but I don't know a lot about electronics and even less about how to fix them if something inside the controller were to burn up. This is asking a lot but if you could let the motors run for a while maybe even with some load, so as to rule out the possibility of them "eventually" frying. Anyways... Much Thanks. -Ryan
go green
If it doesn't work there's one at the bottom of the page here:
electricscooterparts.com - Throttles
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
That's a dual pot and exactly what I need thanks.
go green
So I got the dual pot and it worked fine. I got crazy one late night and tried it on one pot and it worked too. Now I'm running one magura 5k twist throttle for both motors and it works fine. Just thought I'd let you all know. -Ryan ps: check out my site about my bike, electricky.googlepages.com (no www.).
go green
hi i just bought a kollmorgen 300w motor with built in speed controller and have wired it up like the diagram says but it doesnt work could anybody please give me a hand with this thanks
monty