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10 Build Your Own Electric Motorcycle – FULL – 10 DC Motor Control

In the simplest of all worlds we just have a big on switch on the motorcycle you’d flip it and you would just go full tilt but in reality we need to be able to control the speed of the motorcycle have smooth acceleration and be able to go whatever speed we need to and that’s where the motor controller is going to come in now remember that on a dc motor essentially

Speed is based on voltage so a 48 volt electric motorcycle is going to go faster than a 24 or a 36 volt electric motorcycle but the other thing is we’re just getting more power at those higher voltage systems so one way to control the speed would be to control the voltage but at lower voltage we also have to pull more amperage to do the same amount of work so

Wouldn’t it be great if there was some way that we could keep our full voltage and yet control the speed of the motorcycle independently of that that’s exactly what the motor controller does here in fact that’s through a process called pwm pulse width modulation imagine if you have a light switch and you can turn it on and off really fast like a thousand times

A second fast the light bulb that’s connected to it is going to turn on and off well it’s only gonna have full brightness on in full darkness off but if you were able to flip it on and off very quickly you’d be able to get a middle brightness created from full on and full off sort of creating a variable analog from a digital and that’s what this controller does

The mosfets inside the controller turn on and off very very quickly but the duration of the onto the off is variable and that way we can change the speed of our electric motor and yet keep our high voltage system so that we have as much our full torque that entire time now this one here happens to be a curtiss brand i’ve got experience with both curtis and all

Tracks i have an all tracks on this motorcycle this one just happens to be a curtiss it’s sort of a leftover controller from a different project they have a pretty good reputation and let’s start off right on the front of the controller here taking a look at the specs now on the motorcycle it’s a 48 volt 300 amp controller this curtiss one here is actually a 400

Amp controller now you’re going to want as high amperage of a controller as you can get in terms of it’s going to be how fast you can pull away from a stop sign it’s also going to be a hill climbing ability and power but at the same time your batteries aren’t going to like to put out all that much power at once and really for range they want to put out the lowest

Amount of amps as they can so what you really want is a high amperage controller that’s there when you need it but you want to minimize how many amps you’re using for cruising to maximize your range so this particular controller is 48 to 72 volts that’s kind of nice because we could run a motorcycle at 48 volts and in the future if we decided we wanted to get a

Little bit more speed and power out of it we could upgrade by adding 2 more batteries to go to a 72 volt system and we wouldn’t have to change out the controller pretty handy and in terms of the 400 amp rating on this particular controller keep in mind that generally controllers aren’t designed to do that maximum amperage continuously that’s the amperage that you

Can put through the controller for a little while doing a big hill climb or accelerating away from a stop sign you do not want to design your motorcycle to constantly pull 400 amps that’s a lot of power and the controllers not going to be able to handle that now on the back of the controller here’s the power connections on here we’ve got several different ones

We have ones for the positive and negative of the battery pack and then we also have two for going to the motor now typically on a permanent motor setup we actually only use one of those connections and rather than bore you with exactly how those connections are set up i’m instead going to point you to the instruction manual that comes with your controller now

Another great thing is that companies like curtis and all tracks put this information up on their web pages so for example here’s a diagram showing how to hook up the controller but right now even though you have an order to controller yet you can go online you can download this to get a better sense of how exactly you’ll hope that controller up now also on this

Controller we have some adjustments in this case there on the side there’s three screws here that you pull out with an allen wrench and underneath there there’s three potentiometers which are adjusted with a small screwdriver those let you make some adjustments to this including the throttle response the maximum current it allows you to tweak the motorcycle one

Reason why this is important is without a clutch and with a lesser rotation of the throttle then you might have stock you need to be able to tweak the controller a little bit to make it ride the way you want it to be you don’t want a motorcycle where the throttle is so touchy that just by going over a bump you adjust the throttle the motor responds and suddenly

It’s not much fun to drive anymore likewise how you pull out pull away from a stop sign is also important the throttle curve how far you twist the throttle how soon the controller responds that can all be adjusted right here with these connections these potentiometers that are under these plugs now on some other controllers you program them you plug in a computer

Cable and you use a small computer application to change the settings in the controller in the all tracks controller that’s on the motorcycle it’s the part of the ax line up of controllers those are programmed through a computer in this case it’s through a very basic windows application now just a couple other things to keep in mind on this control on the back here

On curtis controllers this first pin is power that operates the controller the the circuitry the logic of the controller that’s the power that’s sort of the on off switch to make this whole thing work and that’s positive pack voltage in this case it’d be 48 volts positive but on some bigger controllers it could be up to 144 volts now the big main power connector

That’s right next to it is battery negative that means that on this curtis controller the full voltage of your pack exists between these two points that are about a centimeter apart so anytime you’re working on a curtiss controller take extra special precaution anytime you’re doing any connections either here or here because it is possible to have voltage in

The capacitors of the controller so even though you already have everything turned off you have the battery disconnect pulled you can still get a pretty bad spark between these two points for example if you’re unplugging this wire here and you accidentally brush it against that connection in fact you can get enough power going through there to vaporize a speed

Connector on the end of the wire going to this connection so just a little precaution for you there another thing great about controllers like these is they have some safety features built in common among them is a high pedal lockout what that means is let’s say you have the throttle on the motorcycle turned just a little bit when you turn the power on instead of

The motorcycle instantly taking off you have to fully release the throttle and then twist it before you’ll get going again also standard on controllers are a high current protection so if it’s going too high of a current for too long it’ll drop the current this is especially good if you’re going up big hills on hot days long distances what it does is it protects

The controller so just keep in mind that there are some safety features built in and make sure you read about those in your is manual so when you’re ready to connect the controller what you’re going to do is follow the manual for how exactly you connect the power cable eng you’ll need to physically mount the controller using its mounting points to the frame of

The motorcycle and then last but not least you’re going to need to wire up the throttle

Transcribed from video
10 Build Your Own Electric Motorcycle – FULL – 10 DC Motor Control By BenjaminNelson