Jaxenro

I know I can run a regular brushed motor without a speed controller, but does a brushless need one to operate correctly?

Matt Kirsch

My Feedback: (21)

Yes. A motor basically several electromagnets pushing against several permanent magnets to make the shaft spin. The electromagnets are energized in a sequence so they push and pull against the permanent magnets at the right time.

On a brushed motor, that sequence is determined mechanically, by the brushes and the commutator. As the motor spins, the brushes contact different parts of the commutator, energizing different sections of electromagnet.

A brushless motor needs the computerized controller to energize the electromagnets in the proper sequence. If you just hooked a constant current to two of the three wires, you'd just energize one section. The motor might move a little, but then it would stick in place until you disconnected the power. If you switched to a different combination of two wires, the motor might move a little more, but then it would stick in place again.

I suppose you could make the motor go around if you switched the wires around REALLY fast, but only Superman or Flash could do it effectively, or for very long

studysession

OK - I have to ask what would this be used for? Only time I know of people not using an ESC is for electric drag cars.

Jaxenro

Just curious more than anything else. I know brushed motors are sometimes used with a simple on/off switch, though less often as ESC's have become cheaper and lighter over time. Was wondering if'n the same could be done with a brushless.

studysession

I wish mate - I have more brushless motors that I have ESC's. Wish I could use a micro switch and nothing more on some of them.

I have more than 8 different brushless motors. But I do not have that many ESC's. I would love to be able to use a micro switch myself on two of my projects.

ArkyTazman

I have seen the statement several times that there's nothing basically different from a brushed ESC vs. a brushless ESC, besides the cutoff setting (and 2X price differential). My question would be, how is the two wire brushled ESC going to control the three wire brushless motor??????? Inquiring minds want to know!

Cheers'n Beers... [_])
Don

Wright Flyer

But that statement is wrong. A brushless ESC is more like THREE brushed ESC's bolted together. Instead of a single power switching circuit (bank of MOSFET transistors) it has three and this is why (until recently) brushless ESC's were 3 times the price of brushed. Due to supply and demand that's now dropping so that they're only about twice the brushed ESC price which actually makes them quite good value for money!

Cliff

ArkyTazman

Yepper, yer right, and after posting that question, I wondered where I ever got that nugget of misinformation planted in my mind in the first place, since it was obviously flawed logic. Only thing I could find was someone comparing the earlier ESC's to the new ones that have additional cutoffs for the lipos, etc., and said they saw no reason for the $$$ necessary to upgrade to a new ESC as long as everything was monitored closely... I must have subliminally compared apples to oranges by thinking old = brushed, new = brushless... Put brain in motion before engaging keyboard...

cubmstr

I am still curious as to how a brushless ESC works? I get the switching power supply bit, I more interested in how a standard brushless ESC can control the varuious styles of motors with differing poles and running at different speeds and still effectively control the motor, most are listed as sensorless but they must be using some type of feedback, yes? I have found several articles on the web on how the various brushless motors work but nothing on their speed controls.

Greg