Looking for a controller

[ronald44181000]

I'm in the process of gathering all the sub-assemblies that are required to finish builing a recumbent tadpole trike that I've designed and I'm in need of some help. What I'm looking for is a controller that I can place between the 36 volt, 500 watt hub motor that I'll be purchasing from Golden Motors and the Permanent Magnet Alternator that will be chained into my front sprocket. My intention is to take the power generated from the pedals and transfer this directly into the alternator and to then have the alternator power the hub motor directly and have any residual power fed to the batteries or vice-versa. Does anyone have any ideas as to how I can go about this?

 

[amberwolf]

Well, you'd just use any controller rated at least as high as what that motor requires.

I assume that you have the batteries being charged from the PMA, and the system then runs from the batteries. That's the best stable way to ensure constant power available to the controller, unless you are producing a lot of excess power at the PMA and regulating away whatever isn't used. (which is inefficient, losing potentially a lot of your pedal energy).

If you are running the controller directly from the PMA, then you must always pedal at the same rate and never stop or slow down or speed up, to ensure the controller can get constant power, or else you will have to setup the PMA/pedals to always produce more power than you will need even at slower pedalling speeds.

But either way, the controller remains the same--whatever is needed to run that motor.

There are some in the for sale section that might work; I thought I saw a used one last night for cheap that might.

 

[CowtownPeddler]

Pardon my ignorance, but I don't see any efficiencies in this setup. Basically, you would have to pedal harder to generate enough power for the hub, which would then assist.

Given the inefficiencies in the conversion of mechanical -> electricity -> hub power, you would end up working harder than if you just left the bike unpowered, at least this is my understanding....

 

[el_walto]

i don't understand why you would setup an ebike like this. You are just wasting energy. If you want Regen, use a hub motor for it.

 

[dogman dan]

Give him a break, it'll be cool and he can pedal slowly at the stoplights and keep the watts flowing. I agree, the losses will make it less efficient than just putting the pedals into a chain drive, but he'll be able to pedal a very constant cadence regardless of the speed he's going, or even while stopped. This could very well make a less efficient setup worth it to him. At worst, it's still better than the experience of the don't bother to pedal riders, or the pedal but in too low a gear to matter riders. Trying to run this bike charging only by pedaling would be too much work to be worth it though. Good only for a road warrior, thunderdome world.

A good source for the controller would be ebikes-ca. Justin is selling a nice infineon now, and I bet he can supply correct halls sequences for a GM. You would want a start immediate for sure that uses hall sensors since you can't pedal first very well with the pedals driving a generator.

Run the generator to the battery, and then the battery to the controller so the power supply is constant, as Amberwolf suggests for sure. The battery could even be pretty small, but Idealy get enough to go a significant distance, and then use pedal power to extend that range. A small battery might not like the charging and discharging whipsaw it would get from starts and hills. A large battery will experience lower c rates doing the same riding and last longer.

 

[CowtownPeddler]

I wasn't trying to give him a hard time, just trying to understand the nature of the setup.

If you were to run the generator through the gearing, you could have a lot of fun with this setup. I don't think you would get any satisfaction by trying to use the hub motor for regen. I'm pretty sure that some of the smaller RC motors could be modified (or not) to work with the infineon controller and provide some regen capability. Doubt there would be much mechanical resistance and the motor choice would really be key to the amount of energy captured.

Certainly, I would use the knowledge gained to apply to something like a wind-powered battery charger or something of the sort.