I am trying to make an electronic speed controller with throttle receiving system. I am wondering what MOSFET should be used. I have a BLDC motor which i have made out of 12V 32 A car alternator. Also what parameters should be identified if i am wanting to use the servo tester like throttle.

 

Welcome to AAC!
A servo tester, if of the type used with remote-controlled models, is not suitable for controlling the alternator as a BLDC. The tester generates pulses at ~50Hz, with a pulse width in the 1mS-2mS range only. A BLDC controller (such as one of these) is much more complex and works at a higher frequency, but can be readily obtained off-the-shelf, probably cheaper than building one yourself.

 

Welcome to AAC!
A servo tester, if of the type used with remote-controlled models, is not suitable for controlling the alternator as a BLDC. The tester generates pulses at ~50Hz, with a pulse width in the 1mS-2mS range only. A BLDC controller (such as one of these) is much more complex and works at a higher frequency, but can be readily obtained off-the-shelf, probably cheaper than building one yourself.

These controllers that you mentioned are 48V. Will I be able to connect 48v controller to the 12V alternator turned motor ? If yes, do I have to provide 48V DC supply ?

 

These controllers that you mentioned are 48V.

Only some. They come in various types/voltage-ratings. Choose one that can handle 12V input.

 

Will the 12V alternator converted to bldc motor wouldn't be able to take more than its rated 12V capacity now that the cut out is removed?

 

What cut-out? As for the motor accepting more than 12V, it probably will but how much more depends on the alternator specification and how you've converted it.

 

Will the 12V alternator converted to bldc motor wouldn't be able to take more than its rated 12V capacity now that the cut out is removed?

They used to make a "box" that you could get 110V AC out of a 12V alternator one without the built in regulator. The same magnet wire is used in the stator of the alternator that is used in a 220V induction motor. So I don't understand why 48V would be a problem to the alternator.

In your alternator to motor conversion, are you still using the winding's on the rotor or are you going to put permanent magnet in the place of the wound coil?

 

I am trying to make an electronic speed controller with throttle receiving system. I am wondering what MOSFET should be used. I have a BLDC motor which i have made out of 12V 32 A car alternator. Also what parameters should be identified if i am wanting to use the servo tester like throttle.

How did you convert an alternator to use as a motor? I would like to that too.

 

How did you convert an alternator to use as a motor? I would like to that too.

The best info I found was on "Endless Sphere". There are a couple of way to do it there just join and search the forum.
https://www.endless-sphere.com/forums/viewtopic.php?t=84537

There was also some info at DIYElectricCar - https://www.diyelectriccar.com/forums/showthread.php/car-alternator-e-bike-motor-89145.html

Much more if you Google

 

They used to make a "box" that you could get 110V AC out of a 12V alternator one without the built in regulator. The same magnet wire is used in the stator of the alternator that is used in a 220V induction motor. So I don't understand why 48V would be a problem to the alternator.

In your alternator to motor conversion, are you still using the winding's on the rotor or are you going to put permanent magnet in the place of the wound coil?

I am using the same rotor and stator only the Rectifier and the regulator goes out

 

Welcome to AAC!
A servo tester, if of the type used with remote-controlled models, is not suitable for controlling the alternator as a BLDC. The tester generates pulses at ~50Hz, with a pulse width in the 1mS-2mS range only. A BLDC controller (such as one of these) is much more complex and works at a higher frequency, but can be readily obtained off-the-shelf, probably cheaper than building one yourself.

I would need a controller without hall sensor as I have not built the hall in my motor. Plus, I would need higher current rating close to 40-50A. Any suggestions where I can get this ?

 

I am using the same rotor and stator only the Rectifier and the regulator goes out

Well from what I learned a few years ago when looking into motors, if you haven't rewound the alternator stator into a different configuration, you are making a DC three phase motor NOT a BLDC. Why I say this is that an alternator has the stator wound in a distributed configuration. This means that the stator coils a distributed around the whole of the stator core like in an induction motor. And that is different than how a BLDC is wound, they are wound as "salient"poles individual poles.

To understand what I'm talking about look for images of a alternator winding pattern then look for a BLDC winding pattern. The difference will surely be able for you to see.

 

Any suggestions where I can get this ?

Do some googling for on-line suppliers.