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The picture below shows an old Siemens controller for an AC system.
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The picture below show a Brusa controller that is available for a wide variety of battery supply voltages. Brusa also recommend their own motors to be used as a package.
----The picture below show a Brusa controller that is available for a wide variety of battery supply voltages. Brusa also recommend their own motors to be used as a package.
----The picture below shows a Curtis 1231C controller. This is probably the most widely used DC motor controller in car conversions. This controller can operate up to 144v at 500A. This will give a reasonable acceleration at that voltage and current. These controllers are very simple to set up and will work with a wide variety of DC series motors. The power control comes through MOSFET (Metal Oxide Semiconductor Field Effect Transistor) that use a high frequency switching technique that controls the average voltage fed to the motor. This voltage corresponds to the position of a potentiometer in the throttle box connected. A potentiometer is a rotary variable resistor. These normal have three terminals; 2 are each end of the resistance track and the other is the wiper. The wiper is connected along the resistance track depending on how much the shaft it is attached to is rotated. This gives a variable resistance. This is the same as the volume control on a radio that has a rotary control. The throttle potentiometer is operated by pressing the throttle pedal. The controller then meters out the power to the motor through the transistor bank (MOSFETs). I am not sure if Curtis have resolved this, but there used to be a nasty whine when pulling heavy loads on initial pull away. This was one of the reasons I did not choose a Curtis Controller. The Zilla controller from Cafe electric is another DC controller, but the business side was a bit rocky, so supply of these controllers is tetchy. They are well sought after as there tends to be 1K and 2K versions that can deliver 1000A or 2000A respectively. This is a mighty lump of power and will put a big grin on the face of the lucky owner.
---- The picture below shows the Zapi H3D DC motor controller and it's programmer unit. This was my controller of choice. Its delivers up to 800A at 120v. That puts a smile on my face. One of the selling points of this controller for me was that it has regenerative braking so I can re-charge the batteries when slowing down or braking. By way of a few control relays I was able to set up a sport / economy switch, so I could limit the driving current and provide bigger regen amounts (economy) or have full driving current and a small amount of regen (sport mode). The economy mode tends to be jerky, so I only use it when I am trying to eek out the range from the batteries. I also got this with a large heat sink for air cooling and forward / reverse and regen contactors as well as a main contactor. The Zapi controller was designed for retro-fitting a Fork Truck with a modern controller, so this provides some nice little extra features that can be used on a car. I use the auxiliary steering contactor output to control a 120v relay linked to the control of my 12v power steering pump and so I get power steering from when I first touch the throttle until 5 seconds after the motor stops. This 5 second delay is programmable. I tried different settings and 5 seconds seems to be about right for normal driving, useful little feature. There are many others too. As my conversion was my first, I wanted as many options to try out different driving situations and set-ups as possible. The Zapi controller gave me this. Be warned that Zapi recommend that you do not attempt a gear change with regeneration enabled as a sudden change in motor speed / load can damage the output transistors. That was what I was told, so I worked out some relay logic to disable regen whenever I pressed the clutch pedal therefore regen is only active when the drive is mechanically fully engaged. It was fairly straight forward to connect up to the motor.
----Before I installed anything into my car, I set it all up on my garage floor. I mounted a plank of wood on the wall and fixed the throttle box to this and some old light switches that could provide the key switch inputs etc. Then I got the whole system working. From that point on, it is just about figuring how to mount everything and repeating the wiring in the car. when I looked at the the system on my garage floor and then at the car, fear set in that it would not all fit in the car. This is understandable. The Ford Probe is quite low, so the height problem is exaggerated, but I got it all in after about 3 attempts. More about that later.
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I hope this has provided some insight into my choice of motors, but yours is based on your own desires. Mine was most definitely not the cheapest solution. For AC and DC systems, more voltage normally means more ability to make the motor go faster. In order to push your car up to speed requires current. More current generally means more torque from a given voltage and this is perceived as acceleration. So for racing, you want a high voltage high current motor controller. AC systems are best here as the motors are capable of much greater speeds with minimal gearing. These systems are more expensive generally. Hub motors do not actually go very fast as they are connected directly to the wheels. However these motors can work at very high voltages too. These are also quite expensive generally. I have seen DC motors doubled up by joining the shafts of two motors mechanically and running from 2 Zilla controllers (checkout "white zombie" on YouTube), but this is not for everybody and can be very costly. Most people converting to electric just want an electric car to behave similar to a normal petrol car for their money, and not too much money either. If you really want to do things on the cheap then you must admire the efforts of forkenswift. A quick search will find details of this Geo Metro with the drive system and motor etc. from a scrap forklift truck. This has got to be the cheapest way to do an electric car conversion. However, this is not for the feint hearted. There is a lot more work needed to match things together and much more research required to track down parts etc. Of course the bonus is the cost. I believe that I have gone midway, ordering some parts at normal rates and getting some parts by arranging my own shipping, scouring salvage yards and eBay to save money.
I have given some examples of motor controllers that I know of, and there are many others that are worth mentioning, but a bit of searching on the web will soon reveal the characteristics and cost of these controllers. I can make updates to this page if you have specific questions. Please use the comments section at the bottom. If you believe that my commentary is in some way wrong or misleading then please use comments. If you have anything else that you want others reading this page to hear about then please leave a comment.
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