Two hub motors and controllers one throttle
- Thread starter hurty
- Start date
yopappamon
10 kW
How are you going to syncronize the two motors so they don't fight each other?
Try one throttle, it might work.
Try one throttle, it might work.
Rassy
1 MW
Hi Hurty. This has been hashed over several times. The answer is a qualified yes. Whether brushed or brushless the best results are achieved when both systems are "identical". I.e. one throttle paralleled to both controllers, which are both wired to one battery pack of adequate AH. The motors and wheel sizes should also be the same.
I have done several projects involving either two or three hub motors running from a single throttle. I've done this with both brushed and brushless.
As long as everything is "identical" as described above the motors do not fight each other at all. In fact, I think they tend to help each other when accelerating or hill climbing, meaning the effect from the two motors is more than double that of a single motor.
Good luck with your project.
I have done several projects involving either two or three hub motors running from a single throttle. I've done this with both brushed and brushless.
As long as everything is "identical" as described above the motors do not fight each other at all. In fact, I think they tend to help each other when accelerating or hill climbing, meaning the effect from the two motors is more than double that of a single motor.
Good luck with your project.
cell_man
100 kW
I use 2 identical controllers and hub motors on my bike with a single battery. I just common the signal wire on the throttle to both controllers and only use the 5V and gnd from 1 of the controllers. It works for me but not saying it's the right or only way to do it.
If you're gonna use 2 motors you need to consider what you are trying to achieve. If you want better acceleration and hill climbing stick to the standard motor for the wheel size. If you want to increase the max speed you'll need higher RPM motors than you would ordinarily use. I'm really happy with the power and speed a pair of strong geared hub motors give me. I chose a faster winding that gives me good max speed in a dual setup without going to very high volts. This route does require a good high C battery though.
If you're gonna use 2 motors you need to consider what you are trying to achieve. If you want better acceleration and hill climbing stick to the standard motor for the wheel size. If you want to increase the max speed you'll need higher RPM motors than you would ordinarily use. I'm really happy with the power and speed a pair of strong geared hub motors give me. I chose a faster winding that gives me good max speed in a dual setup without going to very high volts. This route does require a good high C battery though.
Rassy
1 MW
cell_man said:
I've seen where others have done it this way too. I just paralleled all three throttle wires together on my first experiment, and since it worked have always done it that way. So I guess either way works ok. Somebody did not parallel their batterys together, and the batteries tried to balance through the little throttle wires and components, which of course fried something.
rkosiorek
100 kW
Rassy said:
you should only use the +5V from one of the controllers to the common throttle. reason is that this is an output signal and is not designed to be an input. and these are not usually designed to handle a reverse current. if the +5V is higher on one of the controllers than the other this can feed back through the 5V regulator on the other destroying that regulator.
but this is a cautionary thing. just because it could happen, it does not mean that it will necesarrily happen. but in my mind why take the risk.
rick
grindz145
1 MW
The problem is that, if there are differential impedances between the two signals, they will fight eachother. I know Methods did have trouble with it and I think he only solved it by using 2 throttles built into one.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=12356&p=222185&hilit=2wd+methods#p222185
It's just a voltage divider circuit so in theory it shouldn't be a big deal, but it is a high impedance input and it seems somewhat easy to throw off. It is definitely possible though, I just cant think of a nice simple circuit that I can offer to assure it will work well.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=12356&p=222185&hilit=2wd+methods#p222185
It's just a voltage divider circuit so in theory it shouldn't be a big deal, but it is a high impedance input and it seems somewhat easy to throw off. It is definitely possible though, I just cant think of a nice simple circuit that I can offer to assure it will work well.
cell_man
100 kW
rkosiorek said:
That was why I didn't want to connect all in parallel and I didn't think it necessary. I measured the 5V line on the throttle and there was a small difference between the controllers, but I very much doubt this would cause an issue. I thought I might need to parallel the Gnd as well but it worked just fine with just the signal paralleled to the 2nd controller.
I agree you would want to common the battery negative if running a separate battery for each controller.
rkosiorek
100 kW
i've done this numerous times. as recently as last week, even.
i made up a cable wired this way for some guy in California who is going to use a pair of 5306 motors in the rear of a huge 10 passenger double decker Rhodes Car Quad.
it should be interesting to see how this all works out for him. the car gas 6 adult size seats with pedals and an upper deck with seats for the kids. no pedals on the upper deck. i've never seen a picture of the whole thing. i wonder how tippy it's going to be.
rick
i made up a cable wired this way for some guy in California who is going to use a pair of 5306 motors in the rear of a huge 10 passenger double decker Rhodes Car Quad.
it should be interesting to see how this all works out for him. the car gas 6 adult size seats with pedals and an upper deck with seats for the kids. no pedals on the upper deck. i've never seen a picture of the whole thing. i wonder how tippy it's going to be.
rick
CORBINFIBER
100 W
you can control 3+ hub with one throttle
Kingfish
100 MW
I have one throttle powered by the +5 VDC of both controllers.
The controllers are Lyen 12FET 4110 Extreme Modder, and they share everything = even-steven. The +5 supply line to the Throttle already has an onboard diode to prevent reverse current. :wink:
The controllers are identical except I have the front down-rated by 10% power over the rear to prevent the front wheel from slipping at a dead stop.
The motors are identical (9C Disc F & R) except that I have a 26" rim on the front, and a 24" rim on the back. Both run 2.5 inch wide Hookworms.
The only time I have contention is on flat level ground with no wind (meaning a stiff tailwind) and then I can tell one motor kinda wants to lead and the other to follow. This is not a problem if you put it in Cruize: One will end up doing all the work and the other will add just enough power to keep it freewheeling. When a hill approaches, the lazy motor will kick in. The motor that leads is arbitrary.
99% of the time I can't tell if there's contention. It just works. 8)
Take a look at my build thread in the sig; I have the wiring diagrams posted there. It's pretty easy actually.
Enjoy, KF
The controllers are Lyen 12FET 4110 Extreme Modder, and they share everything = even-steven. The +5 supply line to the Throttle already has an onboard diode to prevent reverse current. :wink:
The controllers are identical except I have the front down-rated by 10% power over the rear to prevent the front wheel from slipping at a dead stop.
The motors are identical (9C Disc F & R) except that I have a 26" rim on the front, and a 24" rim on the back. Both run 2.5 inch wide Hookworms.
The only time I have contention is on flat level ground with no wind (meaning a stiff tailwind) and then I can tell one motor kinda wants to lead and the other to follow. This is not a problem if you put it in Cruize: One will end up doing all the work and the other will add just enough power to keep it freewheeling. When a hill approaches, the lazy motor will kick in. The motor that leads is arbitrary.
99% of the time I can't tell if there's contention. It just works. 8)
Take a look at my build thread in the sig; I have the wiring diagrams posted there. It's pretty easy actually.
Enjoy, KF
zombiess
10 MW
The Xie Chang based controllers many of us use do not share one throttle well. The solution is cheap, but you need basic electronics skill to build it. It's two NPN transistors setup in an emitter follower arrangement which act as a buffer. I implemented this same setup on my throttle interface and it works good to use 1 throttle on 2 controllers with no odd current sharing issues.
CORBINFIBER
100 W
cell-man said how =) along with high C-rating and BMSamps is recommended additionally no syncing is required other than using matching components ,,, (above picture post) ,,,not pictured here is third controller, battery, CF aero fairings and cargo basket)
rkosiorek
100 kW
nieles
10 kW
d8veh said:
what about a single supply op-amp as a voltage follower? only two parts needed. the opamp and a socket to solder the wires to.
any obvious flaws i am overlooking?
Kingfish
100 MW
I use one CA per controller. KISS.d8veh said:
~KF
WhatcomRider
100 W
I routed the single-wire throttle output of my CA V3 stand-alone directly (using a splitter cable) to the throttle inputs of 2 identical 6 FET cellman controllers that power two 350W MAC motors. I installed switches to independently turn each controller on or off. This configuration works well. I usually run the rear motor only - turning the front motor on just for hills.d8veh said:
zombiess
10 MW
nieles said:
You can use an op amp, I tried this myself with an LM358, the problem is you need to supply a voltage higher than the maximum voltage you are buffering. So to use an single supply op amp you need to use an external battery. Using the following setup you don't have this problem and you can power it directly from the controllers throttle power supply which is usually 4.2V.
This is the solution.
Use a pn2222a NPN transistor with a 1kohm resistor going to the base. Throttle signal wire (usually green or white) goes to the 1kohm base resistor. Controller V+(red) and throttle V+ go to the collector. Controller GND (black) and throttle GND are tied together. Re represents your load which is the controller so no resistor is needed.
Build two of them with the throttle signal going to the two 1kohm resistors, all grounds tied together, all V+ tied together. Add more of the same circuit if you need one throttle to run more controllers.
I gave it a try today with a single pn2222a, and I got output from 0.25v to 2.5v. I changed the resistor to a 10K one and it increased slightly to 0.3v to 2.7v. I think that's much too low. Open circuit voltage on my controller was 4.9v and decreased to about 4.00v when I connected it. Have you any suggestions?
Since I got no suggestions, I tried splitting my Cycle Analyst throttle output. I'm now running three motors and three controllers from a single throttle connected to the Cycle Analyst. I'm using two different batteries, so I had to tie the two 0v power wires to stop the throttle value floating on the third controller with different battery. I didn't try it untied, but I'm sure it wouldn't have worked. You should be able to do something similar with any microprocessor that can give a throttle output.
John in CR
100 TW
I can tell you that the CA3 likes having it's throttle wire split to multiple controllers even less that the Infineon type controllers like sharing a throttle. It may work fine at modest power, but not at high power. I was doing it thru a CA3 and at first I was getting the same result, which was an inability to get to full throttle. As I approached WOT power would drop off significantly as one controller hogged the signal. Another symptom was flakiness at WOT with no-load. I was using it for a few rides and Saturday it fried something in the throttle circuitry of the CA. It kinda works, so I was able to ride home, but it was like a loose wire in the throttle and it was the same result not even with just one controller.
There's no way I would tie controllers together only at the throttle using multiple battery packs. That seems like begging for trouble with the good chance that voltage differentials between the 2 batteries under load feeding into the throttle wire. I run dual controllers and the bike does have multiple packs in parallel, but the battery leads are paralleled to within a few inches of the controllers and the negatives flow through a single stand alone shunt.
Zombiess Throttle Tamer is a great solution, though you'll need to talk to him about how to deal with 3.
John
There's no way I would tie controllers together only at the throttle using multiple battery packs. That seems like begging for trouble with the good chance that voltage differentials between the 2 batteries under load feeding into the throttle wire. I run dual controllers and the bike does have multiple packs in parallel, but the battery leads are paralleled to within a few inches of the controllers and the negatives flow through a single stand alone shunt.
Zombiess Throttle Tamer is a great solution, though you'll need to talk to him about how to deal with 3.
John
