BLDC motor from old Audi Turbo Alternator

My 1st attempt at making an Altermotor. 24V using a Radio control Electronic Speed Controller and a servo tester to supply Pulse Width Modulation to the ESC. I do not know the max torque or RPM. Amp draw at full speed is about 2A, really suprizing, not loaded though so Amps will increase when loaded. Still nice knowing it works and we can start doing some alternative energy stuff like energy efficient solar powered pool pump or something from this.
The only problem with ESC is that it doesn't start under load, making it a no-go as motorbike e-motor, but...I'm working on installing hall sensors and pairing it with a BLDC controller from Kelly Controllers and hoping for the best. Comments and suggestions welcome. Greetings from South-Africa.

Category:

Science & Technology

Tags:

• BLDC
• brushless DC motor
• Alternator
• ESC
• Electronics speed controller
• RC
• Altermotor
• Alternator conversion

[smittiefish]

@MrJDesign. No the rotor voltage should be well below 12V, on this setup it a 6Volt motorbike battery was run through a car's ignition coil to bring it down to about 3.5V.

What happens when the rotor coil's voltage is too high is that the ESC cannot get a position reference and the rotor will turn slowly and then stop as the ESC senses that it must be doing overcurrent. Drop the rotor voltage and give it a go. The lower the rotor voltage,the faster it will run but with less torque. Best wishes.

[smittiefish]

Hi MrJdesign, theres is no pot connected to the motor i'm afraid, that is a 3 phase brushless dc motor to electronically commutate the rotor shaft. However, the pot on the controller is a standard 5K ohm linear pot that varies the frequency at which the controller commutates the rotor shaft. The rotor shaft has 6V from an old bike battery connected to power the electromagnet onit. I hope that answers your question? Keep well.

[srobidoux]

Maybe I'm being a stickler, but unless Audi does something different than most manufactures, there are brushes in line with the field winding.

[Ramaom25]

Hello there! I'm very impress with what you done, so that I bought a alternator to try the same thing, but I don't know how to hook up. Could you tell me how did you hook up it and what do I need to buy to make it works.Thanks.

[Ramaom25]

Hello there! I'm very impress with what you done, so that I bought a alternator to try the same thing, but I don't know how to hook up. Canyou tell me how did you did it and what do I need to buy to make it works.Thanks.

[MrJDdesign]

OK, thanks for your advices. It works well, but there is a little problem with potentiometer. It runs only with RC reciever. The current from the ESC way to reciever is about 5 Amps and voltage 5 Volts. Does it mean, that my Potentiometer should have power 25W?

[MrJDdesign]

@smittiefish I tried it, but it doesn´t work. I used a 12 volt battery for a controller and that same voltage is used for rotor wires. Should it be lower?

[Hydropower72]

Hello, God job

Do you have a plan for this electric configuration. I try to make this experience.

Thanks