Need to Make a Custom AC/DC Adapter

Thread Starter

MB107

Joined Jul 24, 2016
345
Hello Ladies and Gentlemen..

Recently I purchased a wireless foot pedal control for a welder which wasn't as wireless as I would have liked. Apparently I have to plug the wireless remote to a 120V AC to 15V DC adapter. Which means another extension chord and other unnecessary hassle. So I though I would stuff my own AC to DC power supply into the welder chassis and eliminate the external one that came with the unit. Seams easy enough but not for someone like me. My electrical knowledge is limited to 2 wires and 12V automotive circuits.

So in any case the welder operates magically with either 240 or 120V AC. It is a Lincoln Square wave 200 for anyone interested. The AC to DC adapter that comes with the welder is rated at 100 to 240V input and 15 VDC output. So I found a board mounted AC to DC adapter with what I believe to be similar ratings CUI inc VSK-S15-15U T. Specs and circuit diagrams are in the attached PDF.

Unfortunately this unit seams to require additional capacitors and MOVs and other stuff that I could hook up as shown but I found many different variations of these parts and don't know what to order. For example what voltage capacitors, and what type. So I'm wondering if its all necessary and there is an optional EMC recommended circuit is that also shown in this application. The Welder does operate with a high frequency arc that occasionally trips my GFIC circuit breakers.

If all this is necessary, can any one recommend components by part number and a source to get them. Or another adapter that has this stuff already buit in.

My other option is to solder two wires to the plug terminals on the unit that came with the welder and tie wrap it inside some where. Not what I like to do.

Any help would be appreciated.
Thank You
John
 

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Alec_t

Joined Sep 17, 2013
14,413
Unfortunately this unit seams to require additional capacitors and MOVs and other stuff that I could hook up as shown
I doubt that any of those components were used with the defective original supply, which looks to be a bog standard universal input AC/DC converter. But perhaps that's why it failed ......
Capacitors on the input and output should have a voltage rating at least 50% more than the 120V supply and 15V output respectively. The input cap should be X2 rated.
 

Thread Starter

MB107

Joined Jul 24, 2016
345
I doubt that any of those components were used with the defective original supply, which looks to be a bog standard universal input AC/DC converter. But perhaps that's why it failed ......
Capacitors on the input and output should have a voltage rating at least 50% more than the 120V supply and 15V output respectively. The input cap should be X2 rated.
Thank you for the quick reply Alec_t.

I will give it a try as is. I do have another question for you if you can help me out. In the wiring diagram the input wires show AC(L) and AC(N) which I understand to mean Line and Neutral. But in my case when I am running the welder off 240V I will be using 2 lines L1 and L2 and will not have a neutral available. My plan was to just put a fuse on both lines. Will this work?
 

Alec_t

Joined Sep 17, 2013
14,413
Should work. My only concern is that a current hungry welder could involve big voltage spikes which might fry the adapter if its input isn't protected by suppression components.
 

Thread Starter

MB107

Joined Jul 24, 2016
345
Should work. My only concern is that a current hungry welder could involve big voltage spikes which might fry the adapter if its input isn't protected by suppression components.
That's my concern so maybe I will take a stab at ordering those other components.

So far I have tried powering up the transmitter on the bench and it works fine at 120VAC with no other components, but I'm having difficulty getting power threw the connector I have chosen. The plug is a 5.5mm diameter with a 2.1mm pin. I cant understand why the one in the attached PDF doesn't work. I have tried putting the negative on both the sleeve and the shunt. Apparently shunt and sleeve are connected once the plug is installed. Not sure what the shunt is used for and I don't thing the one that came with the welder uses one. I think it should be just connected to the sleeve.

But that does bring up another issue. The sleeve will be mounted directly to the chassis of the welder meaning -Vo terminal will be connected to the chassis ground. I'm thinking I may have to isolate the sleeve since I have no idea what -Vo is referenced to.

I attached pictures of both the original plug and jack and the replacement jack I'm trying to use with the plug.
P1000211.JPG P1000213.JPG P1000214.JPG
 

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