Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Robhi on December 15, 2007, 06:55:19 AM
-
hello,
Could I use a PS that is used for a printer for my:--
The XS-3525/8S-4 Stepper Motor Driver Board
The Perfect Choice For Your Sherline or Taig Four Axis CNC Retrofit
Four axis bipolar drive
±2.5 Amp/Phase PWM controlled drives
up to 35 Volt (w/BEMF)
FULL, HALF, QUARTER, & EIGHTH step/Full Step .
The PS that I would like to use is input 220 volte, output is 24VDC/5.0A .
I do not know if that would work.
any help of you will be appreciated.
thanks
Robhi
-
5Amps might just be on the low side depending on how many motors and their current ratings.
Hood
-
If three motors turn on simultaneously they could sink 7.5 amps - way beyond the capabilities of your power supply. If you have four motors - 10 amps.
You could be clever and only run programs that do not move more than 2 motors at once - but ????
A simple way I have my power supply is from two 12 volt leisure batteries which I charge up now and then. The advantage with batteries is that the overall voltage is steady at 24 v (in series) , no matter what the current drawn way beyond the 10 amp mark. It is a bit expensive - about £80 (UK) but, I find, very simple.
I have the input protected by a diode bridge in case I connect them the wrong way round inadvertantly.
-
Hi, thanks for your replies.
the motor that i have are the followings:
220Ncm - 10mm Shaft - Hybrid Stepper Motor
Arc Code AC571157525M
Type Hybrid Stepper
Holding Torque 220Ncm
Step Angle 1.8°
Rated Voltage 7.5V
Rated Current 2.5A/Phase
No. of Wires 8
Size 57x57x115mm
Shaft Dia. 10mm
Shaft Length (Front) 30mm
Shaft Length (Rear) 30mm
Net Weight 1.74kg
I would like to run the three of them at once ( as am not too clever to run only 2), they would be wired in bipolar parallel,
so as you said I might have a PS of 24VDC/7.25 Am or more.
Am I right?
Robhi
-
I think the accepted figure is 2/3 of the total motor current as you are unlikely to be using all 3 axis at full current at the same time. However I would still be wary of using a power supply that is borderline, best bet is to get yourself a toroidal transformer, a rectifier and a capacitor and build yourself a power supply. Bob Campbell has a good pdf on how to work out the figure for the various components of a power supply, you will find it here http://campbelldesigns.com/files/power-supply-part-1.pdf
Hood
-
You are using the same motors as I am. They work very well. I run mine on 24 volts, they get slightly warm but not hot, even when stood a long time.
Unlike an ordinary motor, a stepper motor comsumes power even when stood - the current keeps the rotor fixed in the one position. I think your 5 amp supply will struggle. You will find that the voltage output will dip as the motors take power. The Stepmaster cards I used at first carried a warning not to let the voltage drop below 12v, or everything would overheat.
Try it and see - start by using only two motors connected and see how the supply voltage holds up.
-
hi,
thankx for replies, they are great and useful.
thankx again
robhi