Where does the laser cathode wire connect to the laser PSU?

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jgecik
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Where does the laser cathode wire connect to the laser PSU?

Post by jgecik »

Hello!

I recently purchased a good chunk of the DSP upgrade kit (I didn't need the E-Stop or other accessories) and have it almost all wired up. The machine homes out correctly (as far as I can tell). Many thanks to the users on the forum for their knowledge and willingness to help!

Though, after searching the forum and finding that awesome wiring diagram and following it to the letter, I'm still a bit confused:

I have no idea where exactly the laser tube cathode goes. Here's a picture of my laser power supply:
Image

The anode is wired into the back of the supply. The inlet on the left has four slots labelled (from left to right) L-, FG, AC, AC.

The next has six slots: G, P, L, G, IN, 5V. I know this is used to hook up to the DSP card.

The far right inlet has four slots: 24, G, 5V, L. Could the cathode wire go into one of these slots?

Thank you for your assistance!
-Jordan
Raman Narayan
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Joined: Thu Apr 04, 2013 10:56 am
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Re: Where does the laser cathode wire connect to the laser P

Post by Raman Narayan »

Hi,

I do not know anything about the specific power supply you are using.
But the Catode of the tube goes to the specific cathode connection
provided. I do see a blue wire going out from the middile of power
supply chassis in the picture, and suspect that is meant to be
the cathode connection to the tube.
I do not think it is a good idea to connect cathode of the tube to the logical
gnd you find in the connectors. It might work, but not a good idea(
what happens if the logical gnd somehow is broken, it will lead to
a spark that will destroy all the low voltage logic in your controller,
since most logic chips cannot handle breakdown voltage more than
10V).

Regards
Raman
jgecik
Posts: 39
Joined: Sat Apr 13, 2013 9:16 pm
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Re: Where does the laser cathode wire connect to the laser P

Post by jgecik »

Raman Narayan wrote:Hi,

I do not know anything about the specific power supply you are using.
But the Catode of the tube goes to the specific cathode connection
provided. I do see a blue wire going out from the middile of power
supply chassis in the picture, and suspect that is meant to be
the cathode connection to the tube.
I do not think it is a good idea to connect cathode of the tube to the logical
gnd you find in the connectors. It might work, but not a good idea(
what happens if the logical gnd somehow is broken, it will lead to
a spark that will destroy all the low voltage logic in your controller,
since most logic chips cannot handle breakdown voltage more than
10V).

Regards
Raman
I don't know anything about it either, unfortunately. For most of the models that people have posted on the forum, it seems like the cathode connection is inside the unit, though peering in, I'm not seeing any place to make a connection that isn't one of the plugs. Thank you for the advice, for now, I'll have to bide my time and wait for any hints as I dig through the forum.

Thanks, Raman.
natsterrr
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Re: Where does the laser cathode wire connect to the laser P

Post by natsterrr »

On the laser psu I got from light object, there is a screw terminal on the back of the psu which is for the cathode.
jgecik
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Re: Where does the laser cathode wire connect to the laser P

Post by jgecik »

natsterrr wrote:On the laser psu I got from light object, there is a screw terminal on the back of the psu which is for the cathode.
Could I trouble you to take a picture of it? I don't think my laser PSU has a screw specifically for the cathode.
Tech_Marco
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Re: Where does the laser cathode wire connect to the laser P

Post by Tech_Marco »

jgecik wrote:
natsterrr wrote:On the laser psu I got from light object, there is a screw terminal on the back of the psu which is for the cathode.
Could I trouble you to take a picture of it? I don't think my laser PSU has a screw specifically for the cathode.
Can you post pictures from the the back of the PS. Better sent a more clear image and I may be able to recall how to connect it

Marco
jgecik
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Re: Where does the laser cathode wire connect to the laser P

Post by jgecik »

Here are some pics of my laser PSU. I bought my cutter at the beginning of 2013, so I was thinking it was a slightly newer model than what others have been working with, one that doesn't have a cathode that wires in at the rear of the PSU.

Back of the laser PSU:
http://s1199.photobucket.com/user/jgeci ... 6.jpg.html

Front of the PSU:
http://s1199.photobucket.com/user/jgeci ... aa.jpg.htm

Middle inlet on the PSU, where the DSP controller hooks in:
http://s1199.photobucket.com/user/jgeci ... 9.jpg.html

Leftmost inlet on the PSU, where the 24v power supply hooks in:
http://s1199.photobucket.com/user/jgeci ... 7.jpg.html

Rightmost inlet on the PSU. This had wires running to and from it, as I recall. Could this be where my cathode hooks in?
http://s1199.photobucket.com/user/jgeci ... 6.jpg.html

On my cutter, the cathode wire led from the tube, to the "big green" resistor (which has been removed), into a yellow wire that led to the "current indicator" (also removed). In the setup guide, this then leads to the back of the PSU, but I don't recall any wires (aside from the large, thick anode) coming from the back of my laser PSU. Could the cathode wire lead to a slot on the rightmost inlet on the laser PSU?

Thank you for your help, everyone!
Tech_Marco
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Re: Where does the laser cathode wire connect to the laser P

Post by Tech_Marco »

On the the front connector, there is one marked "L- FG AC AC" I believe the F- is the negative of the output. It should be 'ground' to the 'FG' as well. FG= Ground and AC = AC power in (110V or 220V depends on your model)


Marco
jgecik
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Re: Where does the laser cathode wire connect to the laser P

Post by jgecik »

Tech_Marco wrote:On the the front connector, there is one marked "L- FG AC AC" I believe the F- is the negative of the output. It should be 'ground' to the 'FG' as well. FG= Ground and AC = AC power in (110V or 220V depends on your model)


Marco
I have those connections, but those are the ones linked from the electrical outlet to the main on/off switch, then into the 24v power supply. I also have a 4-slot green inlet on the right side of the front of the laser PSU labelled "24V G 5V L-". Could one of these be where the cathode wire goes?

Thank you again, Marco.
-Jordan
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