3Phase Brushless DC Motor Drive

799

08:25:04

Sensor-based control of a Three Phase Brushless DC Motor with Hall Sensors. 

these motors are common in floppy disk drives and some hard disk drives.  In this example the hall sensors are located on the far left and indicate the polarity of the armature above the stator. 

The U, V, W phases have three states each: high, low, and floating. As each hall sensor changes state, logic controls the fets to switch the phase high (source current), low (sink current), or off (block current)

found all of this from atmel:
http://www.atmel.com/images/atmel-2596-sensor-based-control-of-three-phase-brushless-dc-motors_application-note_avr443.pdf

published 12 years ago

Sine_eyed

12 years ago

Cool circuit! The clean layout and good description make it easy to follow- nice job. Are those the little, kinda more flat motors you find in cd/dvd rom drives or am I thinking of steppers?..

UncleRick

12 years ago

I am curious, faceblast. Now I do not have any real experience with brushless motors, but, that being said, let me ask a couple of questions. I am presuming that the pulse sources at the left side, are acting as the Hall effect units. As I understand Hall effect devices, their outputs are un-powered transistor (open collector&emitter), requiring pull-up (or pull- down) resistors to carry their signals to the next stage, are they not? I wouldn't expect them to drive LEDs directly, without some sort of current source. Of course I could be wrong. Could you clarify that operation for me, please? TIA. :-)

faceblast

12 years ago

LEDs are just indicators for illustration purposes in simulation. Driving LED from a hall sensor requires an amplifier as the output is about 6 pissamps.

faceblast

12 years ago

@Sine_eyed exactly that. There are a multitude of different types of motors. I'll put another circuit up showing different types of motors being simulated

UncleRick

12 years ago

Pissamps?? I don't remember that term, from school. <grin> I'm trying to find a conversion algorithm for it, with no luck. lol!

rbrtkurtz

12 years ago

Pissamps lol. I like your style, Faceblast.

faceblast

12 years ago

faceblast

12 years ago

@UncleRick I found a fan in my junk with a four terminal hall sensor chip with switching built in; it's driving the coils directly with no extra parts. Can't see the number or manufacturer though :(

UncleRick

12 years ago

Thanks faceblast. I looked around and found there are many different interfaces including several analog circuits. So much for this old dog to learn. ;-)

abdula

10 years ago

Its so hard to me :(

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.