Searching \ for '3 phase' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: massmind.org/techref/index.htm?key=phase
Search entire site for: '3 phase'.

Truncated match.
PICList Thread
'3 phase'
2009\04\15@140632 by graham foulkes

picon face
Hi, What a great group of people. Anybody got any suggestions about driving
small, high speed 3 phase motors. I have a small die grinder that runs up to
10,000 rpm. Plate says 'MOGFREKVENS H F 400 - 1200 Hz 3PH  17 - 50 volts 75
watts. The manufacture  I think it is Swedish manufactured but the motor
plate has been defaced . No 563 Rotorn Fabric Hallas Stilla PA  Inkopplad
motor is all that is ledgible.
Regards Andy

2009\04\15@143029 by Sean Breheny

face picon face
You can buy small, inexpensive variable frequency drives (VFD) which
are meant to drive small industrial motors. However, 400-1200Hz seems
very high - usually full speed is 60Hz AC input and you need to reduce
the frequency for lower speeds.

Sean


On Wed, Apr 15, 2009 at 2:06 PM, graham foulkes <spam_OUTbespoken1TakeThisOuTspamgmail.com> wrote:
> Hi, What a great group of people. Anybody got any suggestions about driving
> small, high speed 3 phase motors. I have a small die grinder that runs up to
> 10,000 rpm. Plate says 'MOGFREKVENS H F 400 - 1200 Hz 3PH  17 - 50 volts 75
> watts. The manufacture  I think it is Swedish manufactured but the motor
> plate has been defaced . No 563 Rotorn Fabric Hallas Stilla PA  Inkopplad
> motor is all that is ledgible.
> Regards Andy
>

2009\04\15@163028 by graham foulkes

picon face
Hi SeanThanks for the suggestion. It is a high spindle speed and the rating
plate states '400 - 1200 Hz'. that's the problem, most 3 phase inverters
I've checked out are either square wave, (too lossy at this frequency) or
low cycle, 60 Hz. I was hoping for a PIC based design running PWM at high
frequency.
Cheers Andy

On Wed, Apr 15, 2009 at 2:30 PM, Sean Breheny <.....shb7KILLspamspam@spam@cornell.edu> wrote:

{Quote hidden}

2009\04\15@164902 by William \Chops\ Westfield

face picon face

>>> I have a small die grinder that runs up to 10,000 rpm. Plate says  
>>> 'MOGFREKVENS H F 400 - 1200 Hz 3PH  17 - 50 volts

>>  However, 400-1200Hz seemsvery high

> It is a high spindle speed and the rating
> plate states '400 - 1200 Hz'. that's the problem, most 3 phase  
> inverters
> I've checked out are either square wave, (too lossy at this  
> frequency) or
> low cycle, 60 Hz. I was hoping for a PIC based design running PWM at  
> high
> frequency.

Check out the "brushless speed controllers" aimed at radio control  
modelers or the designs for same that you can find at places like  
rcgroups.com (though it may be difficult to find one at that sort of  
voltage; they tend to run big amps at lower voltages.   Here's one  
that claims up to 25V: http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=4315&Product_Name=hexTronik_PRO_80A_BESC_w/_PC_Programmability
 )

(for that matter, such brushless motors are all the rage, though  
perhaps not at that speed; check out recent "motor control" app notes  
from your favorite microcontroller vendor.)

I would think that 1200Hz matches up with a 6 or 7 pole motor; putting  
one cycle of a sine wave into a particular phase (along with the  
accompanying phases) turns the motor 1/6 or 1/7 of a turn.  Repeat  
1200 times per second, and you get 1200*60/n RPM (12000 rpm for 6  
poles...)

BillW

2009\04\15@195051 by graham foulkes

picon face
Thanks Bill, I will check them out.Graham

On Wed, Apr 15, 2009 at 4:47 PM, William "Chops" Westfield
<.....westfwKILLspamspam.....mac.com>wrote:

{Quote hidden}

> -

2009\04\16@022301 by Ruben Jönsson

flavicon
face
> I have a small die grinder that runs up to 10,000 rpm. Plate says
> 'MOGFREKVENS H F 400 - 1200 Hz 3PH  17 - 50 volts

If it is swedish, the word probably is HÖGFREKVENS which means high frequency.
The second letter is an O with two dots over it (&Ouml;).

/Ruben

==============================
Ruben Jönsson
AB Liros Electronic
Box 9124, 200 39 Malmö, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
EraseMErubenspam_OUTspamTakeThisOuTpp.sbbs.se
==============================

2009\04\16@091929 by graham foulkes

picon face
Hi Ruben
Thanks Ruben, my command of the Swedish language is increased by 100%, (the
rating plate is pretty beat up).
Regards Andy

2009/4/16 Ruben Jönsson <rubenspamspam_OUTpp.sbbs.se>

{Quote hidden}

>

More... (looser matching)
- Last day of these posts
- In 2009 , 2010 only
- Today
- New search...