Car alternator hack

[1wicked2008]

??? what r u doing exactly nothing !!!

[22filin]

Great job!

What is the frequency of the oscillator ?or

You can get the outline circuit of your generator 555

in my email box filin206@rambler.ru

Thanks

[n3glv]

Every car alternator I have ever been inside had SLIP RINGS and BRUSHES.

(They are electro-magnetic)

The only way this would work is if the rotor had a PM field. Was it modified?

[OrmuScout]

@n3glv Yes, a bit, I removed the rectifier bridge and used an old computer PSU to supply the field current to the rotor. The ESC was connected to the stator windings.

[juancarlosruiz1985]

This would benice for a e-bike conversion.

[chilidress]

how many amps(max) does it draw if you are trying to stop it with your hand or what's the stall amperage?

[chilidress]

rpm? torque?

[OrmuScout]

@chilidress I haven't tested yet.

[chilidress]

time to make E-bike

[Albear20]

this + 1/5 scale RC = EPIC WIN

[chinowa69]

lol brush less dc motor are patent from so long ago



[theCTCamp]

Your biggest problem is under a decent load, the alternator won't be able to hold much higher than 16v. Without a load it can go upwards to 35 - 40v without overheating, but once you put a strain on it, drops off quick.

[RODALCO2007]

That alternator runs very smooth

That RC controller puts out a 3 phase 12 Volts supply i guess.

[generator5500w]

@RODALCO2007 yea that's right, it 3 phase outlet

[wudz337]

Thanks for the reply, in the mean time I have been testing a Sensor-less ESC as I did not want Hall Sens,but at present only testing on12v with a three phase brushless motor and in test can drive a max of 10amps at a max of 50v. The Mosfets have as yet no heat sinks but hope to parallel up the six Mosfets. Good to watch the ESC find the Phase and direction in a couple of seconds...got the alternator ready once got the Fet's heatsinked. The ESC is a commercial unit but will modify as we go along.

[wudz337]

Thanks for the reply, in the mean time I have been testing a Sensor-less ESC but at present only testing on12v with a three phase brushless motor and in test can drive a max of 10amps at a max of 50v. The Mosfets have as yet no heat sinks but hope to parallel up the six Mosfets. Good to watch the ESC find the Phase and direction in a couple of seconds...got the alternator ready once got the Fet's heatsinked. The ESC is a commercial unit but will modify as we go along.

[MrMaleBee]

how long can you run this before it burns out?

Thanks

[OrmuScout]

@MrMaleBee

Very long, it doesn't even get warm when running with low load. I haven't tested it with heavy loads yet.

[wudz337]

Sorry ESC side of the circuit interests me, have you details of the output circuit.

Cheers John

[OrmuScout]

@wudz337

I used a commercial RC aeroplane ESC which is connected to the stator coils. The ESC control signal is generated using a simple oscillator based on the NE555 timer chip and the rotor (field) windings are connected to an old PC power supply.

[wudz337]

hi,

How are you feeding the field coils, are you using power Mosfets driven by the 555.

Any circuit for the power side of the speed control would be great...

well done

John

[MrJDdesign]

Hi, I´m trying to do something similar, but I have two questions. First, what did you do with the rotor wire? And secondly, what is the little circuit you connected to ESC? Is it a simple potentiometer, or something more? What type od potentometer did you use?

[OrmuScout]

@MrJDdesign

I used an old PC power supply to supply the field current to the rotor winding. 3.3V and 5V voltages seem to work best when there's no load but it depends on the alternator.

The ESC (at least most ESCs) is controlled with a standard 50Hz servo control signal (1ms pulse = power off, 2ms pulse = full power). I used a simple oscillator circuit based on the NE555 timer chip to generate the signal. Search for "ne555 servo tester" if you need circuit diagrams.

[MrSensible1]

Hi I'm trying this also but can't get mine to crank very fast. I read somewhere that we need to limit the current to the rotor windings to reduce the magnetic field ??? how are you changing the speed in this video ? by limiting the current or changing the voltage ?? Thanks

[OrmuScout]

@MrSensible1

Yes, lower field current allows the motor to spin faster but it also reduces torque. If you have an adjustable power supply you can easily test how the field voltage/current affects the alternator.

[d3adp001]

now thats pretty cool. would work for a large scale rc car.

[bootywild]

What size ESC did you use?

[OrmuScout]

@bootywild

It's rated at 70A constant current. Check item 11983 at DealExtreme for more information.