View Full Version : DC Fan Motor

18-10-2012, 07:39 PM
Anyone has an idea how to connect this motor to an external supply?
I guess the 280VDC is the power supply for field and the 15VDC for the commutator .
But what's the 0-5VDC (control voltage ? For what purpose)
What 's the yellow wire? Seems some sort of pulse transmitter but then, for what purpose

18-10-2012, 07:49 PM
Found this interesting file

18-10-2012, 07:51 PM
Another one http://spg-usa.com/pd_brushless_oem_pop.php
Using 3 different power supplies seems a little bit complicated, isn't it?

18-10-2012, 08:06 PM
Digging deeper and deepr, this is a BLDC motor - never heard of it before - and there seems to excist controllers for this. These BLDC motors are found in every AC unit these days

18-10-2012, 10:53 PM
Hi Peter,

Yes, these motors are common in todays AC systems.
Easy to spot from the plug connector - 5 cables in a 6 or 7 pin plug, red cable up one end, then a gap, then the other cables.
Red-340V DC
Black - Neutral
White - 15V DC supply to power internal PCB
Yellow - Speed input command
Blue - Speed output signal

From diagrams I've seen the speed input signal is a pulsed input. Not sure if a PWM signal or just on frequency.
I think speed output is a pulsed one, speed determines frequency but then this a depends on the internal PCB really.
Inside the Motor has a little inverter circuit and uses the 340V DC to switch through the motor windings on the stator to work the thing. Stator is normally a 3 phase star wound affair and rotor a permanent magnet.
BLDC means Brush Less, Digitally Commutated.

Yours looks like a variable voltage from 0 - 5V DC to signal input speed on yellow then a pulsed output to indicate motor speed on blue.

19-10-2012, 02:37 PM
Connecting a stable 280VDC and a 15VDC source will not run this motor I guess.
Can this do the job you think

19-10-2012, 10:46 PM
Don't think so.

From your first diagram it looks like the motor has its own internal PCB which does the job. I suspect the controller just listed does the same thing externally and just hooks up to the stator windings.
Might be worth getting the 280V and 15V supplies to your motor, then apply a 0-5V on the yellow and hopefully it should spin.

Maybe turn it on with a long stick just in case.

22-10-2012, 09:50 PM
I would love to get or make a tester for these motors. Would 240 V AC through rectifier and capacitors give approx 280 volt DC that could work as a power supply?

22-10-2012, 10:27 PM
Probably give a bit more. 240 is the rms voltage. Peak voltage is 340V so you should be nearer that. depending on how smooth you get the waveform after the diodes would give a lower / higher average value.

install monkey
22-10-2012, 10:38 PM
isnt the 5 vdc and the 15vdc input just an alternative speed tapping for night time when fridge blinds are shut where as the 280vdc input is the hi speed normal input