SIP 130 Power settings modification??

[regcheeseman]

Whenever I use my wonderful SIP I have an issue with the power settings, MIN -LOW is too low and MIN - MED seems too fierce.

I'm welding a rotten VW with 0.6 wire

Thanks to this forum, I think I've done all the other mods (liner/torch/brace/PSU) and I was wondering if anyone has done any work to get a little more control of the power output - was thinking of using an SCR setup to limit the input side???

Or should I just pension off the 20 year old SIP and treat myself to something new, I do like those do all chinese units but are they a case of jack of all trades - master of none?

I'm only a hobbiest with a family to run, so budget is pretty limited.

 

[mike 109444]

Look up buck and boost

 

[regcheeseman]

Found the urban myth thread, makes sense.

The primaries are switched by the SIP power setting switches, so if I parallel my buck/boost tranny before the switches that should give me an extra +/- power setting IF I incorporate a DPDT you mentioned.

Is +/- 12V sufficient/too much? Would a 24 or 6 V tranny make more sense - I've no idea of the output differences with the standard SIP power switches.


Cheers!

 

[mike 109444]

You need to see (meter!) to find what you have already. Get a digital meter and meter between the earth clamp (one that clamps to the work) and the welding tip (remove shroud and back off wire feed. As you work your way up through the power settings (operating the trigger) you should get aprox 14 to 25 ish volts DC you did remember to set meter to DC! write down the values that way you have a reference for any mods done. Before you leap in and go the buck and boost you could try an additional inductor to add to the existing one to boost it a bit on the low power setting.
I am stuck in hotel on poor connection so not the best location to find info for you. Will add more when on home broadband.

 

[mike 109444]

Back on me broadband...
See pics curtsey of "normspanners"
But note you are dealing with MAINS voltage. IF you don't understand, don't dabble.

 

[mike 109444]

Another option would be to add (add more?) capacitance. Is your machine one of the big old type sip's? (an IDEAL model maybe) Just looked at your first post and with the MIN MAX switches would guess not.

 

[regcheeseman]

Thank for the info

But note you are dealing with MAINS voltage. IF you don't understand, don't dabble.

I'm quite happy working with electronics, it's my bread and butter

My sip is not one of the old type, though it does seem to be doing an acceptable job of my Golf at the moment.

The hole in the floor

Fixed

 

[octo0072000]

Whenever I use my wonderful SIP I have an issue with the power settings, MIN -LOW is too low and MIN - MED seems too fierce.

I'm welding a rotten VW with 0.6 wire

Thanks to this forum, I think I've done all the other mods (liner/torch/brace/PSU) and I was wondering if anyone has done any work to get a little more control of the power output - was thinking of using an SCR setup to limit the input side???

Or should I just pension off the 20 year old SIP and treat myself to something new, I do like those do all chinese units but are they a case of jack of all trades - master of none?

I'm only a hobbiest with a family to run, so budget is pretty limited.

have you tried it on 0.8 wire i prefer to use 0.8 to 0.6 wire on thin stuff

 

[regcheeseman]

have you tried it on 0.8 wire i prefer to use 0.8 to 0.6 wire on thin stuff

I have, I prefer 0.6.

 

[mike 109444]

Hope that's not the fuel lines I see through the hole...... (brake pipes I hope )
Your welds look good to me. I think what you are looking for is finer adjustment on your SIP which is where the bigger welders score, having 6, 8 right up to 12 power settings and some (porta potty mig) I thing has 12 course and 12 fine !
When I rewound the transformer for mine (not SIP) (orignal 6 power settings) I added more taps to give 10 (I think?) power settings I can't comment on whether it's better as it was a fried transformer when I got it.
If you do go down the SCR route don't forget to post up results.
One thing I have been thinking of trying is using one of the yellow 240 to 110 v transformers which would half the input and to see what the output would be like then. Remembering that there are several devices that require the 240 in via there own transformers ie gas valve, wire feed motor, pcb ect. You would need to use the upper power levels to get back to near the original output?
Another option would be to work on the inductor coil by adding or subtracting. A coil of wire (insulated) wrapped round an iron core such as an iron pipe or similar. (could be done externally inserting in the work ground lead by clamping one end on earth lead and using car starter jump lead to continue onto the work piece. Or bypass the original coil and insert your made up one. You may then need to try other power settings to reset-up.
Keep us posted if you try any

 

[migmug]

Read this
http://www.st.com/st-web-ui/static/...ical/document/application_note/CD00003856.pdf
You may need to add a capacitor to the output

 

[regcheeseman]

Read this
http://www.st.com/st-web-ui/static/...ical/document/application_note/CD00003856.pdf
You may need to add a capacitor to the output

Thank you.

Hope that's not the fuel lines I see through the hole...... (brake pipes I hope )

Yes, they were brand new brake lines, which I cleverly chopped through with the slit disc in the grinder