Readybuilt power supplies for GeckoDrives

[christipher saint denis]

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]

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]

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]

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]

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

[christipher saint denis]

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]

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

[Mike Richards]

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]

Christipher,

Cheap multimeters are notorious for unreliable readings.


DocTanner

[christipher saint denis]

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]

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]

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]

"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]

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]

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]

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]

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


230

[Richards]

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]

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]

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]

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]

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]

Thanks Gerald,

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

Greg

[Richards]

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]

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]

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]

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]

Mike,

Would you mind posting a picture of your setup?

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

Thanks,
Greg

[Richards]

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]

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 ?

[Richards]

Greg,
When you use the G203 stepper drivers, on the PMDX-122, place the JP1 jumper on pins 2 and 3 to select common ground. You need to tell Mach 3 to send the step and direction pulses Active-HIGH because you are sourcing the signals. That means that the normal state of the signal, when it is off, is LOW or near ground potential. When the signal goes high, it is sourcing current and is active.

The BOB buffers the signals from the parallel port to the G20x stepper drivers. It does NOT invert the signals. The state of the signal (high or low) is passed directly to the G20x.

(The confusing part of this is that for those using the G201 or the G202, do just the opposite. Set JP1 jumper to pins 1 and 2 and set Mach 3 to be Active-LOW. The G201 and G202 sink current, so their normal off state is at 5V and their on state is at 0V.)

By the way, Greg, you're coming along a lot faster than I did when I first tried my hand at electronics.

[Greg J]

Thanks Mike,

That makes perfect sense.

As for me picking this stuff up fast ... well .... its just fun. Its bad when you go to bed thinking about all this and wake up at 0500 without the alarm wanting to read a manual.

Coffee's ready, got some reading.

Again, thanks.
Greg

[Doug_Ford]

Gerald,

Since grounding has come up as a topic over the past couple of days, could we go back a few months and discuss what you wrote in post #4 of this thread?

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.

By now, it's no secret that I'm electrically challenged so it probably won't surprise you when I say that I've read and reread what you wrote and I can't figure out how to do what you've written here. I think I understand the second half of the quote. I should run a wire from the + terminal to a terminal on the DIN rail and jumper it so that I can connect four wires to the Geckos. Same thing with the - terminal on the PS. In the first half of the quote, are you saying that I need to run a ground wire from the PS chassis to the lug on the control box enclosure in order to ground it? That would seem to make sense.

[Gerald D]

In this post (http://www.mechmate.com/forums/showthread.php?p=2669&postcount=2), the - terminal of my power supply is the screw on the capacitor, the one nearest to the Gecko's. And there you can see how busy that screw gets. The point I was trying to make in the quote above is that the little terminals of the Antek are inadequate as serving as the main terminal points and that the DIN rail terminals need to be used to "jumper" the wires together. But you got that. The first part was just to say that "many" things have to get connected to the terminal, and I wasn't trying to be precise as to "how" to connect them.

The power supply chassis is screwed to the mounting plate in the control box, which in turn is screwed to the outer control box enclosure. If you use those "star" washers, or even just spring washers, which bite through the paint, you don't need to add any ground wires across those mechanical connections - they are sound ground paths. Same with alu heatsink plate, that's also soundly connected to the rest of the enclosure.

So you have all the mechanical parts forming a single big "chassis". Now you need to connect 3 wires to this big "chassis":
1. from the negative (-) terminal of the Antek power supply (either directly or via some "jumpering" in the DIN connectors)
2. from the metal parts of the table/gantry/car/slide
3. from the building's ground in the incoming mains power cable

[gmessler]

I'm a little confused about the grounding issue as well. In the thread "my steppers giving trouble Mike says

Many engineers consider it safe to connect all DC GROUND conductors together. Many engineers also consider it safe to connect all DC GROUNDs and AC Earth GROUND together. You must verify that only the DC HOT or PLUS conductor is switched. Whenever possible, I float the DC GROUND. What that means is that there is NO connection between the DC circuits and the AC circuits except through the transformer.

As I read it there shouldn't be an issue grounding the DC negative. But would it be better to Float it?
Question is either to float or not the DC ground. Will floating that ground effect the way the shield on the stepper cables is grounded?

Also to maintain opto isolation between the PMD122 and the 203v's should you not want to connect all the DC negatives together?

I'm not aware of any switching of the DC that needs to take place so I assume (bad idea) that the comment about switching the DC was a general statement.

I don't mean any disrespect Gerald or Mike. :) Just want to make sure I hook everyting up correctly and don't end up with any smoke.

[Gerald D]

No problem Greg.

In my thinking, the issue of whether or not to connect the DC negative to ground relates to potential interference of signals. It does not relate to smoke or safety. Mike is the expert with these things. I merely repeat what I've heard from a group of experienced people and what has worked for me.

[Richards]

If everything is properly grounded, using the method that Gerald has described, then having a common ground for all power supplies will work very well - and would be the best method in this case.

The main problem that I've seen in devices that have failed when a common ground point is used has been 100% due to incorrect wiring or switch failure. When a switch is used to switch only the ground side of a circuit, which should never be done, bad things can and do happen. When a two-pole switch is used that switches both the + and the - side of a DC circuit (which may be required by code for safety reasons to lock-out a circuit for maintenance), and the switch fails with the + side welded, bad things can and do happen. But I've never ever had a problem with any device that had all of the grounds connected together and only the + side of the circuit was switched.

[Doug_Ford]

Crystal clear. Thanks Gerald and Mike.

[gmessler]

Best to stick with what works. Thanks guys :)

[Robert M]

Hi All,
Anyone has/knows another source than Antek for ready built power suppliesat reasonable prices ?
Reason I’m asking is, since august 14 I have left 3 messages to John voce box at an interval of +/- 3 days each + 2 at the general reception last week asking for anyone to call back since I want to place an order for a power supply !!.
As of to day, still no reply either by phone or email :confused:???
Thanks, Robert

[Richards]

Robert,

When I first started my test-bench project, I bought an Avel Y236801 500VA 25V+25V from Parts Express (currently $79.29 plus shipping) and a PMDX-135-8020 power supply board (currently $119 plus shipping). Those two parts are all that you need to build a power supply. If your power supply requirements are 50VDC or lower and the current requirements are 10A or less, PMDX also has the PMDX-136-5010 ($55 + shipping).

I have also built several power supplies with toroidal transformer, a computer grade capacitor (large "can" type, 15,000uF or greater), and a bridge rectifier; however, finding large computer grade "can" type capacitors is becoming more difficult. The smaller "snap-cap" type, which are designed to be soldered to a mounting p.c. board, have taken over.

[Doug_Ford]

Robert,

Based on my experiences with John at Antek and Mr. Richards' reassurance, I built my own power supply. Piece of cake. Take one evening and read some of the websites and I think you'll feel comfortable enough to try it.

[Robert M]

Thanks Doug for you support :)
I’m totally in favor of your direction.
Mr Richard, you & many others out their give me the assuring push to go there, making my own. Actually, I may add, it feels more coherent with the MM approach, built your own.
Sure it’s easer & to some safer to buy one, but also fun & rewarding making one ?!
I’ll look in to that, Robert

BTW… What do you mean by Based on my experiences with John at Antek.... :eek:

[Doug_Ford]

Robert,
I guess you weren't a member of this forum when I had my problems. I ordered a PS from Antek and it took forever before I received it. I had to call several times. Then I changed my mind and decided I wanted a different voltage so I ordered another one. Both times, Antek charged my credit card on the day I placed my order. I made several calls about the second one and never received it. Finally, I gave up and built my own. It still took forever to get the charge for the second PS off my credit card. I was never cheated by Antek but I found them to be extremely slow to respond. I believe John is an honest guy but he's either very disorganized or very overworked.

[Robert M]

Hi Doug,
Thanks for your input :)
Sorry if my memory or my lack of not searching, I should of look at your personal page before asking :o
I’ve been lurking and reading on this forum since early 2006, so I’ve read some, remember some and, hate to admit at my age (43), forgot some :eek:
In your case, my hope for John is let say he’s a little victim of his success, that is overwork mixed with some disorganization??
Sorry to hear you did not get good service out of what seemed to be a fairly good business !
Regardless, I’ am still challenge & fascinated by this making my own, but if it’s = or more expensive to make, I may vote to buy ?? I’ll see the out come if John has time or means to call back and show some interest in my business, as little it may be !!
Later, Robert ;)