power supply Antek PS-5N70R12

cbboatworks · #1 Tue 09 October 2007, 22:29

Hello

I need some input on ordering my power supply,I have emailed Antek and ask them for a 300 Watt supply 70VDC and a small auxiliary output for the PMDX-122 (7-12VDC (non-regulated) or 9VAC, 200mA max). they responded with this stock number (PS-5N70R12) they are telling me that they do not have the 300 watt 70vdc with 12vdc.can I use the PS-5N70R12?

Thanks

Gerald D · #2 Tue 09 October 2007, 23:07

Give us links to the specs please - the part numbers don't ring any bells. How many amps do you expect your motors to draw?

Richards · #3 Wed 10 October 2007, 03:13

The PS-5N70R12 power supply is rated at 70VDC @ 7A, and 12VDC @ 1A. The minimum size transformer that is normally needed for a CNC router with four stepper motors is four times the amps required for one motor multiplied by 0.66. So, if you were using 2A motors, you would need 4 X 2A X 0.66 = 5.28 Amps. A power supply that produces at least 5.28 Amps should be used. More (higher) amps is even better.

cbboatworks · #4 Wed 10 October 2007, 04:39

Hello Gerald

The Link for the Antek PS-5N70R12 is below.also I have added the link for the motors I will be using. Thanks

Motors (MotionKing 34HS9801)
Power Supply (PS-5n70R12)

http://www.toroid-transformer.com/

http://www.motionking.com/34HS_Stepp..._1.8degree.htm

Quote:

Originally Posted by Gerald D

Give us links to the specs please - the part numbers don't ring any bells. How many amps do you expect your motors to draw?

Gene

Gerald D · #5 Wed 10 October 2007, 07:25

4 Amp per motor, times 4 motors x 2/3 (two-thirds) puts you at 10 to 11 Amps.

Multiply that by your 70 Volts and you are talking 700 to 770 Watts.

Antek has supplies either 600 Watt or 800 Watt. If you want to stick with the 70 Volt, you will have to get a 800 Watt supply. If you drop to 56 Volt you can use a 600 Watt supply.

smreish · #6 Wed 10 October 2007, 09:58

Gerald,
Is there a noticeable difference in table/cut performance between the 56V and 70V power supplies?

Sean

Gerald D · #7 Wed 10 October 2007, 11:02

I havn't played with voltages so I don't know how much difference there really is.

smreish · #8 Wed 10 October 2007, 11:19

Gerald.
I just had a wonderful phone conversation with Mariss and got my answer - along with a lot of amazing motor/driver design data!
Long story short is....anything over the the useful load/torque/speed parameters(cornering) of the machine is essentially wasted. After 15 minutes of calcs on the phone based on a Mechmate w/ 7.2 Orientals and 5 203V geckos....I needed roughly 570w @ 53 V. So....600w@56V is ideal. Now to call John at Antek and place an order.

I know that this cornering thread was covered in detail in the forum and hope to not go there again. My brain hurts from all the math!

Sean

Marc Shlaes · #9 Wed 10 October 2007, 11:36

Sean,

I know your brain hurts from the math but... short of everyone repeating the same scenarios, would you be able to make this info available for re-use by creating an Excel spreadsheet?

Would that work? Would it be appropriate? Thanks.

Gerald D · #10 Wed 10 October 2007, 12:08

Let's first help Gene . . . . . .

His motors have an inductance of 4.1mH. So his ideal voltage calculates as 1000*SQRT(0.0041) = 64 volts. His choice of 70V might be slightly high - downside is some extra heat, but upside is max performance. If he goes for 56V his motors will be cool, but the performance will be slightly off the peak. My gut feel is that the hit on performance is very small, and I would be tempted to go for the 56V for his motor. (at 600W)

Gerald D · #11 Wed 10 October 2007, 12:12

Marc, the formulae are simple - see first post in this thread:
http://www.mechmate.com/forums/showthread.php?t=56

cbboatworks · #12 Wed 10 October 2007, 14:14

Gerald I would like to thank you for answering my questions. I am now able to order my control box components. I will order the PS-6N56R12 from antek. and I will be placing my order for the motors from MotionKing # 34HS9801 on Thursday.Thank

Gene

Quote:

Originally Posted by Gerald D

Let's first help Gene . . . . . .

His motors have an inductance of 4.1mH. So his ideal voltage calculates as 1000*SQRT(0.0041) = 64 volts. His choice of 70V might be slightly high - downside is some extra heat, but upside is max performance. If he goes for 56V his motors will be cool, but the performance will be slightly off the peak. My gut feel is that the hit on performance is very small, and I would be tempted to go for the 56V for his motor. (at 600W)