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-   -   Readybuilt power supplies for GeckoDrives (http://www.mechmate.com/forums/showthread.php?t=54)

christipher saint denis Sat 31 March 2007 14:20

Readybuilt power supplies for GeckoDrives
 
Here are photos of my AnTeck PS-8N70Rxx power supply. The close-ups are the 70Vdc 11A unregulated output block and the 5v 1a regulated output block. I drew in the + c - marking because they did not show up in the close-up of the 70Vdc output.

http://www.mechmate.com/Forum/messages/17/3716.jpg

http://www.mechmate.com/Forum/messages/17/3717.jpg http://www.mechmate.com/Forum/messages/17/3718.jpg

Gerald_D Sun 01 April 2007 07:24

That terminal block for the output is going to cause some headaches......

Gecko wants you to take a wire from each drive directly to the power supply. With 4 Gecko's, it is going to be impossible to get 4 wires safely under each screw of the terminal block.

I wonder if the chassis of your supply is connected to "-" terminal of the output?

christipher saint denis Sun 01 April 2007 11:13

I can call the Anteck tomorrow and ask if the chassis of my supply is connected to "-" terminal. Is there any other way I can tell?

mutimeter reading from the output terminal block:
35Vdc between + and -
70Vdc between + and c
70Vdc between c and -

Is this what I should expect?

As far as wiring the Geckos to that output block what do you suggest?

Thanks again for you time.

Gerald_D Sun 01 April 2007 12:45

Christipher, you should be reading 70V DC between + and -, not 35V DC.

When the power supply is switched off, AND HAS BEEN OFF UNTIL THE +/- voltage HAS DROPPED TO 0V, ie. the capacitors have discharged, measure the ohms between the chassis and the terminals.

Standard practice with a Gecko supply is to connect the - to the chassis, to the whole control box, and that is also connected to the ground of the incoming 110V line. Which means a lot of points need to be connected to those terminals. In your case, take good wires from those two terminals to the connectors on the DIN rail. The DIN rail connectors are easier to bridge for multiple wires.

christipher saint denis Sun 01 April 2007 13:33

I measured the ohms between the chassis and the terminals and there is no continuity between them.

christipher saint denis Sun 01 April 2007 14:50

I downloaded my multimeter manual and learned how to read the multimeter correctly. Those readings I posted earlier were incorrect.

multimeter reading from the output terminal block:

49 Vdc between the + and -
http://www.mechmate.com/Forum/messages/17/3722.jpg


My 110Vac power line in reality measures closer to 98Vac. Is that why I am only getting a 49Vac output from my power supply?

James Webster Sun 01 April 2007 15:27

Is the power only 98VAC everywhere in your house, or just at that outlet?

Mike Richards Sun 01 April 2007 17:48

That reading is curious. Even if you had 120VAC available, the unregulated DC would be about 60V. My 50V toroid transformer produces a measured 70VDC (50 * 1.4 = 70V).

You have something connected to the output of the power supply (red wires). Is it possible that your load is too large for the power supply? (I can't imagine Geckos and steppers pulling an 800VA down that far. The four G202s or four G203s that I use and four 3-amp motors don't pull my 500VA supply down at all.)

DocTanner Sun 01 April 2007 18:53

Christipher,

Cheap multimeters are notorious for unreliable readings.


DocTanner

christipher saint denis Sun 01 April 2007 21:42

I will purchase a better multimeter and try taking some new measurements tomorrow. There was no load on the supply when the reading was taken. Those two red wires were attached to empty terminal blocks on my din rail.

Thanks for the help.

Gerald_D Sun 01 April 2007 22:55

Christipher, in the photo with the meter I see you used 2 red wires from the power supply terminals. May I please make a very strong suggestion that you use 2 different colours for + and -. It is too easy to make mistakes when they are all the same colour.

I also believe there is something wrong with your meter. Maybe it was damaged at some time, or maybe it needs new batteries.

Christopher Saint Denis Tue 03 April 2007 18:44

I went and purchased an Idea #61-702 multimeter, which was ten times the cost of my cheap multimeter.

"You get what you pay for."

Once again I find truth in the old saying.

The readings from the new multimeter seem on par with expectations. My incoming 110v line reads 123 Vac and the output from my power supply reads 68.8 Vdc.

Gerald,
Thanks for the heads-up concerning wire coloring. A nest of red wires can get pretty disorienting. It was especial silly of me considering I had a spool of white and black sitting in the next room. I wired up the Pmdx-120, one Gecko G203, a stepper, and the relay for the router. I have got motor movement and I can turn a 110v light bulbs on and off through Mach 3 with m3, m5. All that with out any fireworks and smoke!

Thanks for everyone?s input.

Gerald_D Tue 03 April 2007 23:09

"I have got motor movement and I can turn a 110v light bulbs on and off through Mach 3 with m3, m5. All that with out any fireworks and smoke!"

I don't think you realise how much pleasure I get out of hearing something like this! CONGRATULATIONS!

Greg J Sat 28 July 2007 14:50

I've mounted all the hardware and working on the wiring.

Quote from an earlier post,
"Gecko wants you to take a wire from each drive directly to the power supply. With 4 Gecko's, it is going to be impossible to get 4 wires safely under each screw of the terminal block."

What is the proper way to wire the Gecko's to the PS??

Greg

Gerald D Sat 28 July 2007 21:26

Greg, which Gecko's do you have? With the G201's a lot was said about exact wiring methods, adding fuses and capacitors. Now with the G203, nobody seems to worry about these things any longer.

How big a wire can you fit to your PS? What does the terminal on your PS look like?

Richards Sat 28 July 2007 21:37

Greg,
Take a look at the photos that Gerald posted:

http://www.mechmate.com/forums/showthread.php?t=282

The terminal blocks make wiring simple and easy to trace when things break. You can buy terminal blocks with built in fuses for the positive (+) power lines.

Greg J Sun 29 July 2007 09:29

1 Attachment(s)
Here's a pic of my setup (and I used IRFANVIEW :))

I'm using the G203V drivers and the PS-3N70R9 power supply. I am using terminal blocks, but it looks like there isn't any more room for the wires than the terminal block on the PS. The wires from the PS to the drivers will be either 18 or 20 awg. I'm not using sheilded cable for the kitchen project.

Greg


Attachment 230

Richards Sun 29 July 2007 11:20

Terminal blocks can be fitted with jumpers that screw several blocks together so that they act as one block. If you do that, then you could have one wire going into a set of four blocks and one wire out of each of the four blocks, each going to a separate G203. Most terminal blocks have a threaded hole right in the middle of the top that is designed to receive a jumper.

Greg J Sun 29 July 2007 11:42

Thanks Mike,

WOW, my terminal blocks have a threaded hole right in the middle. Never even noticed. Doesn't take much to get us ME's going.

I'm assuming that you can buy standard jumpers? I'll search Factorymation's web site and start looking.

Greg

Greg J Sun 29 July 2007 11:57

Found the jumpers. They have 2 and 10 pole.

I assume that to jumper 4, you just cut a 10 pole down to 4?

Greg

Greg J Sun 29 July 2007 13:16

Jumper'ing the terminal blocks makes since. But, somewhere on this forum, it was mentioned that the Gecko's didn't like being wired to a "rail" (I think it was mentioned in my posts on the electrical schmatic).

What's the difference between jumper'ing terminal blocks and a "rail".

Greg

Gerald D Sun 29 July 2007 22:55

The neatest solution that I can think of for this case (4 wires into 1 terminal) is a neat solder job. Use about 1" of the thickest wire that the terminal will take, solder the 4 wires to it, put a heat shrink sleeve over the whole lot.

It would help if Antek provided more terminals.

The G203 does not need an external fuse - it already has an internal fuse.

Greg J Mon 30 July 2007 05:59

Thanks Gerald,

I ordered some jumpers last night. I'll try both methods and send the results.

Greg

Richards Mon 30 July 2007 08:42

I'm a little confused about the difference between between connecting four 'regular' conductors to 1-inch of a heavy 'master' conductor and using four terminal blocks jumpered together with a heavy jumper. The M4 size blocks that I use are almost exactly 1-inch per four blocks.

In a more traditional application where voltage rails are used, such as seven foot rails that can be found in some rack-mount computer stacks, you could have a voltage drop along the length of the rail. That's one reason that many industrial systems use a 48-volt rail. The 48-volts is reduced to 24V by resistors and regulators on each board that is plugged into the master rail.

The G201 stepper driver, that didn't have built in 470uF caps, was particularly sensitive to daisy-chained power supplies and poorly designed rails. The G202 and the G203 don't normally need external 470uF caps.

In my designs, I use grounding terminal blocks for all ground connections. Those blocks are mounted next to each other on one end of the DIN rail. Most text books tell us to use a single grounding lug bolt as the common connection for all ground leads. I go for 'easy' instead of 'perfect' and use the terminal blocks. All of the AC Neutral leads to all devices are assigned its own terminal block and all terminal blocks are jumpered together. I use the same method for all DC return leads. AC hot leads and DC positive leads start out the same way with either the AC hot or the DC positive supplied through jumpered terminal blocks, but, I always use a fused terminal block between any device and the power supply. (I even do that for the G203 because it's easier for me to replace a fuse in a terminal block than it is to take the cover off the G203 for maintenance.)

Gerald D Mon 30 July 2007 10:25

Mike, I am not happy with the G203's internal fuse either. Aside from the fact that it is under the cover (which can only be removed if the Gecko is off the heatsink), nobody stocks it in this country. It is a very specialised fuse. A second, external, fuse might not be the first to go - my luck says the internal one will go first.

On the terminals, my slight resistance is just in finding enough space to mount the 8 terminals. Greg's DIN-rail is relative short. And his rail's location makes a long path from the PS to the Geckos. If he were to go with terminals, then a second DIN-rail would be in order.

Life would have been so much simpler if Antek supplied more connection points on the PS.

Marc Shlaes Mon 30 July 2007 12:15

Don't I recall that someone on this forum has a pretty decent relationship with Antek? Could we specify to them what would be a perfect configuration for the MechMate? Then the new guys (like me :eek:) could simply order a MechMate power supply. :):)

Richards Mon 30 July 2007 13:57

Gerald,
The G203 fuse is a pain to get to. Under normal usage it should never need replacing, but if and when it does need to be changed, it will take some time. Since the Gecko G203 internal fuse is rated at 5A, I use a 4A external fuse, with the hope that the external fuse will blow first.

You're right about the space taken by the DIN rail and terminal blocks. My test setup has a rail that is 20-inches long. At the moment, 19-inches are filled with terminal blocks - and there are still more circuits to add.

As long as the connecting wire between the power supply and the drives is heavy enough, length should not be a problem. I use 16-gauge wire with a 4-foot run without problems on my test bench.

Greg J Mon 30 July 2007 15:22

Mike,

Would you mind posting a picture of your setup?

I'm wondering if I've left something out.

Thanks,
Greg

Richards Mon 30 July 2007 17:17

Greg,
My two test benches are just rat's nest wiring which were never intended to be seen by anyone but me. The truth is that I add and subtract components everytime that I turn either of the test benches on. My intent is to never use either the G202 test bench or the G203 test bench in actual production until something fries in my Shopbot controller. Until then, I'll probably add and remove various types of switches, sensors, I/O devices, etc. to see how each new component works with Mach 3 and either the PMDX breakout board or the Gecko G100 module.

Greg J Mon 30 July 2007 20:38

Mike,
I understand. Thanks.

This may not be the appropriate thread (or forum for that matter), but, I'm reading the manuals for Mach3, PMDX-122 and the Gecko G203V. The Mach3 wants settings for the Motor Outputs configuration. The step and dir pin #'s are self-explanatory. I don't understand the lowactive checkmark for the step and dir. I understand the meaning of lowactive, and Gecko's require an active-lo signal (I think). Where does the BOB come into play since it's between the parallel port and the gecko drivers.

Do I want "LowActive" for step and dir in Mach3 ?


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