Simple Motor Question
Simple Motor Question
(OP)
Please forgive my ignorance.
I know this is a Mickey Mouse question.
Am I right to assume ALL brushed motors are DC?
It's not a trick question.
It is just a motor I have taken from a vacuum cleaner.
I was told the control board can be by passed, but the motor I have has got brushes.
(I'm presuming the board is a rectifier / speed control as it has 2 diodes, a triac and a AS25B01 IC and a few other passive components.
Surely there is no way this motor can be connected directly to AC without the above mentioned board?
So, getting back to the question, is it true that an AC motor NEVER has brushes?
Thanks
I know this is a Mickey Mouse question.
Am I right to assume ALL brushed motors are DC?
It's not a trick question.
It is just a motor I have taken from a vacuum cleaner.
I was told the control board can be by passed, but the motor I have has got brushes.
(I'm presuming the board is a rectifier / speed control as it has 2 diodes, a triac and a AS25B01 IC and a few other passive components.
Surely there is no way this motor can be connected directly to AC without the above mentioned board?
So, getting back to the question, is it true that an AC motor NEVER has brushes?
Thanks





RE: Simple Motor Question
RE: Simple Motor Question
So is it possible to attach such a motor to AC directly, or does it need some circuit to do some rectification etc first?
Thanks
RE: Simple Motor Question
RE: Simple Motor Question
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Simple Motor Question
Thanks for clarifying that.
Does that mean the board is a speed controller?
The vacuum cleaner started puffing out black carbon dust and making strange noises.
I'm just unsure if the motor is faulty, or is the controller doing something strange, or not doing what is meant to be doing.
I just tried it directly on the AC and the behaviour is just like with the controller attached.
I've had the motor totally disassembled and couldn't see any obvious faults.
Each of the field windings measured 0.3 ohms but I've no idea if that is normal or not.
The armature windings didn't show any resistance at all, with probes attached to various commutator pads.
I will be buying a new motor but would like to have some confidence that it is the culprit.
Thanks
RE: Simple Motor Question
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Simple Motor Question
The circuit board is a bit of a puzzle. I've never seen or heard of a vacuum that had a variable speed motor. We can tell you exactly what it does if we had a picture of it.
Before spending on a new motor consider a "Hoover Air Steerable". We're pleased with its performance, use it about 3 times a week (freakin dog) and it probably costs about what your motor will.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Simple Motor Question
Ignore the capacitor desoldering.
I removed it to test it but it is fine.
RE: Simple Motor Question
RE: Simple Motor Question
RE: Simple Motor Question
A.
RE: Simple Motor Question
I began to wonder is it to make it UK / usa compatible.
The label on the cover is 220V - 240V 50Hz 1400W
I don't suppose they would label it in that way if it could cater for multiple input types.
The motor is buried inside again, so I need to remove it again to see there are details on it, but I don't think it has a label directly on the motor.
I suppose a datasheet for the AS25B01 IC might give a clue but haven't found one yet.
RE: Simple Motor Question
The minimum and the maximum value of output voltage, usually are preset with serial resistor and proper resistance of potentiometer.
RE: Simple Motor Question
All the parts on there have private part numbers for the vacuum company so you can't look them up.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Simple Motor Question
My Milwaukee Magnum drill is fed AC, but has brushes.
Items 8 and 12 here-
http://www.ereplacementparts.com/images/milwaukee/...
RE: Simple Motor Question
I couldn't find a fault and the carpet was growing a beard, so I just bit the bullet and bought a new one.
Thanks everyone for your replies.
RE: Simple Motor Question
Keith Cress
kcress - http://www.flaminsystems.com
RE: Simple Motor Question
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Simple Motor Question
The one chip looks like AS25B01. I found just a picture on a German website http://www.radiomuseum.org/tubes/tube_as25b01.html with similar connections. It's not proprietary to the vacuum cleaner maker; but it looks like it predates the conversion to the internet of specs, so there's no telling what the specs are without access to an old and large library.
The big one is an ST BTB12-600B; the discoloration suggests it fried. It's under $2 not including shipping/handling.
See the G(ate) and A2 solder pads. It matches the pinout in this document:
http://www.st.com/content/ccc/resource/technical/d...
If the motor doesn't run when the two connectors that were attached to the board are shorted, then it's possible the motor went first, taking out the Triac. Since the rest of the circuit isn't in the current path to the motor it should be OK; replacing the Triac will let the circuit work. Of course you need a motor.
I don't see any short circuit protection but I suppose if the motor fails, the rest will be discarded. If it's really bad the breaker/fuse to the outlet will stop the fire.