Messages

881

General Mach Discussion / Re: Power Supply Unit

« on: January 13, 2011, 09:09:08 AM »

No one can help with my previous post?

I would like to know if the transformer looks ok
If the capacitor selection range is ok
Bridge rectifier selection

If no answer, perhaps I should go to another forum to finalize this projects?

Thanks

882

General Mach Discussion / Re: Power Supply Unit

« on: January 12, 2011, 08:41:03 PM »

Ok we are getting somewhere now.......

Gerry helped me to locate the transformerand it looks good
http://www.mpja.com/prodinfo.asp?number=7846+TR

For the capacitor I will get one from the store in my area, around 30 – 50 VAC, 10000 – 20000uf

For the bridge rectifier the choices I see from the same store as the transformer are:
400PIV, 15A
1000PIV, 15A
50PIV, 25A
400PIV, 25A
50PIV, 35A

Dont know what PIV means, is my choice in one of the above?

883

General Mach Discussion / Re: Power Supply Unit

« on: January 12, 2011, 08:36:22 AM »

The conclusion so far is:

1) I would like to know if I can connect the ground wiring from tha AC along with the Ground (Black) from the DC (I plan to use a metal bar on my board and connect the AC ground plus the DC black wire there)

2) It seems that toroidal transformers are not easily available. Searching on the web I found no places where I can purchase them and eBay does not have the size I want. Antek has them but they are out of stock. Anyone knows where I can buy them?

3) Rectifiers seems that is easy to purchase

4) As I understand now, the capacitor has to be a multiple of 50VDC or perhaps more? Anyone can suggest a safe combinations (uf / vdc)?

884

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 08:32:10 PM »

Thanks for bringing it up, a very good tip

885

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 03:26:32 PM »

I have two pilot lights rated for 110VAC which I want to install on the control station for my CNC. Would they work if I supply them with 40VDC?

Also I have a toggle switch rated 10A, 250VAC which I want to control 8 LED lights. Would this switch work if I connect it to 12VDC?

I dont confuse the ground, neutral and line on the 110V circuit. I just wanted to know if I can connect the ground from the 110VAC along with the ground (Black wire) from a DC circuit

Well the store close by does not have any toroidal transformers neither rectifiers but they do have a large selection of capacitors
10000uf, 25V, $3.99 (that thing is HUGE)
8200uf, 25VDC, $2.99
5500uf, 25VDC, $1.99

When I buy the capacitor(s) how do I secure them to my board? I noticed on the .pdf document from Cambel that he has some kind of pipe clamps at the bottom. Do I buy these clamps separetly?

Anyone knows an online store to buy the toroidal transformer and rectifier?

886

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 09:26:44 AM »

The attached is part of the last page from the CambellDesigns document and I have some questions:

1- When he says all ground wires should be attached to one point, does this mean AC and DC ground?

2- Then he says to run a wire from the + terminal on one of the capacitors to a terminal strip because later    you will run a wire from the terminal to the fuse block. What this fuse is for?

887

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 08:33:12 AM »

Sounds good so far, I'm going to this store this morning to see what is available regarding toroidal transformers, capacitors and rectifiers.

Then I would like to know what gauge wiring I should use plus I want to put a fuse on both the incoming 110VAC and outgoing 25VDC. Before I proceed with the build I will post a wiring schematic including materials list and if all is ok then I will do my purchasing. Who knows, I might have a new power supply even before the one I ordered from China arrives LOL......

Nicolas

888

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 07:25:43 AM »

LOL..........thanks Rich, now I get it but I should have thought about before by myself. Guess too much to digest at once.

So now that Ian said to get a transformer with 25VAC secondary, what will be the VA of this transformer? 402VA?

889

General Mach Discussion / Re: Power Supply Unit

« on: January 11, 2011, 06:48:24 AM »

Thank you Ian for your input and lets see if I can clarify the data.

Keling told me by email that for the 4 motors I have the voltage range on my power supply should be from 24-72VDC

Probotix states in their manual that the 4 drivers I have the power supply voltage should be limited to about 42VDC (your link for the drivers is correct)

I thought about it that the transformers secondary must be available in certain std. size and my next question here would have been what size my choice should be. So you have answered my question before I even asked. I will get one at 25VAC

There is something that confuses me and I would like it to be clarified. You said the transformers secondary comes in .......25VAC. I thought that these transformers have a primary side which is the AC volts and a secondary side which is the DC volts. So is the 25 volts AC or DC?

Thanks for your time
Nicolas
 

890

General Mach Discussion / Re: Power Supply Unit

« on: January 10, 2011, 09:51:22 PM »

Thanks RICH, good explanation