- Thread starter MartZ0r
- Start date
hey buddy, i havnt had chance to look at it again yet, been using my old welder to do the few bits i needed.
atm i am in the process of re-building my workshop so once i finish that i shall get back onto it.
i did get a few components ready just incase i needed them, they were pennies!
atm i am in the process of re-building my workshop so once i finish that i shall get back onto it.
i did get a few components ready just incase i needed them, they were pennies!
right, thought id let ya know i got the welder back out again. finally finished building my workshop (i rebuild 2 stroke bikes)
removed the PCB and replaced the 2 transistors near the relay on the PCB. when i re-fitted and press the ptorch trigger the relay stuck on. (the wirefeed relay)
can only assume the BC107 is not the right transistors as this hasnt happened before. relay #2 that activates the contactor still come on instantly so it has to be something else causing it anyway.
Im at a loss with it really, might bypass the part of the board that controls the second relay and make my own or source another board for the welder.
removed the PCB and replaced the 2 transistors near the relay on the PCB. when i re-fitted and press the ptorch trigger the relay stuck on. (the wirefeed relay)
can only assume the BC107 is not the right transistors as this hasnt happened before. relay #2 that activates the contactor still come on instantly so it has to be something else causing it anyway.
Im at a loss with it really, might bypass the part of the board that controls the second relay and make my own or source another board for the welder.
Wedg1e
They call me Mr. Bodge-angles
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right, thought id let ya know i got the welder back out again. finally finished building my workshop (i rebuild 2 stroke bikes)
removed the PCB and replaced the 2 transistors near the relay on the PCB. when i re-fitted and press the ptorch trigger the relay stuck on. (the wirefeed relay)
can only assume the BC107 is not the right transistors as this hasnt happened before. relay #2 that activates the contactor still come on instantly so it has to be something else causing it anyway.
Im at a loss with it really, might bypass the part of the board that controls the second relay and make my own or source another board for the welder.
Post the PCB up to me, I'll sort it for you. Can't be much wrong with it.
the thread lives on, after Weg1e fixed my welder it seems i got some more issues with the Cap's.
Just for the rercord, incase it may help someone else..
the issue that was keeping the torch staying live is we think the PCB had been bypassed before. i replaced the possible faulty components and still nothing, wedg1e took a look at it and noticed the switch i fitted was wired wrong and corrected it. when i wired it i replicated the switch i removed so looks like it was bypassed or something, there was also something briged.
onto the new problem. i have a blown smoothing Capacitor. it had been shorting out on the buss bars and i cant get it to charge up. the other 2 caps charge from my multimeter and seem fine. the shorted cap also smells horrid.
the caps are sprague Extralytic 22000uF, 40v. Been looking at these but not sure if they are ok to use. Clicky!
Goign to test the rectifier and see if the diodes are ok too. Will post back about that when i test it.
Just for the rercord, incase it may help someone else..
the issue that was keeping the torch staying live is we think the PCB had been bypassed before. i replaced the possible faulty components and still nothing, wedg1e took a look at it and noticed the switch i fitted was wired wrong and corrected it. when i wired it i replicated the switch i removed so looks like it was bypassed or something, there was also something briged.
onto the new problem. i have a blown smoothing Capacitor. it had been shorting out on the buss bars and i cant get it to charge up. the other 2 caps charge from my multimeter and seem fine. the shorted cap also smells horrid.
the caps are sprague Extralytic 22000uF, 40v. Been looking at these but not sure if they are ok to use. Clicky!
Goign to test the rectifier and see if the diodes are ok too. Will post back about that when i test it.
Wedg1e
They call me Mr. Bodge-angles
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Those new caps look OK to me... electrolytics don't last forever anyway so don't be surprised if they start going down one by one. I think I spotted 1981 as a date code on your Romarc so 30 years from a component that is notorious for failure unless charged regularly isn't bad going.
I had an experimental hifi power-amp go pop on me one day: the bang blew the paper and foil contents out of the capacitor all over my lounge, took bloody ages to clean up! Electrolytics almost always die on switch-on. If you soft-start them they last longer but who designs circuits properly...?
Incidentally I'm getting a bit miffed seeing MIG sets claiming to be XXX Amps output when the components are clearly under-rated - 130A diodes in a 160A set?! My 200 has 175A diodes if I recall correctly. Even my TIG set only has Triacs rated for the exact claimed output - 170A. I'd be speccing at least 20% overhead. I accept that the set is probably capable of a split-millisecond peak output of rather more than the component rating but that's like the days when Amstrad used to claim 200W output from a plastic midi-system. They dressed it up as PMPO (Peak Music Power Out) which was some industry techno-horsecr@p-speak created to impress the chav in the street when ghettoblasters ruled. In reality it was about 2W RMS, the only number that really matters
I had an experimental hifi power-amp go pop on me one day: the bang blew the paper and foil contents out of the capacitor all over my lounge, took bloody ages to clean up! Electrolytics almost always die on switch-on. If you soft-start them they last longer but who designs circuits properly...?
Incidentally I'm getting a bit miffed seeing MIG sets claiming to be XXX Amps output when the components are clearly under-rated - 130A diodes in a 160A set?! My 200 has 175A diodes if I recall correctly. Even my TIG set only has Triacs rated for the exact claimed output - 170A. I'd be speccing at least 20% overhead. I accept that the set is probably capable of a split-millisecond peak output of rather more than the component rating but that's like the days when Amstrad used to claim 200W output from a plastic midi-system. They dressed it up as PMPO (Peak Music Power Out) which was some industry techno-horsecr@p-speak created to impress the chav in the street when ghettoblasters ruled. In reality it was about 2W RMS, the only number that really matters
Those new caps look OK to me... electrolytics don't last forever anyway so don't be surprised if they start going down one by one. I think I spotted 1981 as a date code on your Romarc so 30 years from a component that is notorious for failure unless charged regularly isn't bad going.
I had an experimental hifi power-amp go pop on me one day: the bang blew the paper and foil contents out of the capacitor all over my lounge, took bloody ages to clean up! Electrolytics almost always die on switch-on. If you soft-start them they last longer but who designs circuits properly...?
Incidentally I'm getting a bit miffed seeing MIG sets claiming to be XXX Amps output when the components are clearly under-rated - 130A diodes in a 160A set?! My 200 has 175A diodes if I recall correctly. Even my TIG set only has Triacs rated for the exact claimed output - 170A. I'd be speccing at least 20% overhead. I accept that the set is probably capable of a split-millisecond peak output of rather more than the component rating but that's like the days when Amstrad used to claim 200W output from a plastic midi-system. They dressed it up as PMPO (Peak Music Power Out) which was some industry techno-horsecr@p-speak created to impress the chav in the street when ghettoblasters ruled. In reality it was about 2W RMS, the only number that really matters
Wedg1e, at my service again.
you know RMS, constant power used to wind me up so bad. people claim they have a 1000w argos stero that out performed my 300w RMS cerwin vegas. Nice.
the diodes were 130A each and one side of the transformer has one each, so wouldnt that allow alot of ampage overhead? maybe this machine is just too small for my needs then.
and another note on the amp speculations. do you think that is the case in this situation? rather a more peak power 160 rather than a useable 160? older machine tend to be more honest rather than todays machines here marketing is so competetive?
i picked up 2 x 22000uF capacitors today. the ones i linked to.
is it worth still putting in my two original ones that still work? not sure if you can mix caps but i cant see any harm myself, they are the same voltage ratings.
oddly enough i never welded on power 1 or 2, but i tested it today and noticed the wirefeed struggles. the motor humm's at around 1/4 of the max wire speed and start's to turn about haly way. Seems a bit odd, like you dont have full feed range. il take a look at that tomorrow too.
Wish i had the cash for another welder, i go away on hols monday! i should cancel it and get a portamig instead lol. i like fixing things and messing with stuff but when you need to use it it's just annoying!
Martin
is it worth still putting in my two original ones that still work? not sure if you can mix caps but i cant see any harm myself, they are the same voltage ratings.
oddly enough i never welded on power 1 or 2, but i tested it today and noticed the wirefeed struggles. the motor humm's at around 1/4 of the max wire speed and start's to turn about haly way. Seems a bit odd, like you dont have full feed range. il take a look at that tomorrow too.
Wish i had the cash for another welder, i go away on hols monday! i should cancel it and get a portamig instead lol. i like fixing things and messing with stuff but when you need to use it it's just annoying!
Martin
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If one cap has failed due to age, the others may not be far behind, good idea to replace them all if affordable.
Thanks robotstar5, good thinking.
fitted the caps today and what a difference it has made!
penetration seems more "consistant" and the arc is so much more stable. it no longer sounds fierce and more of a consistance sizzle
best way i can explain it!
that was just with the 2 new 22000uF caps fitted so i may get some more later on.
i do have one more question though, just to help me understand it a bit more.
looking at the transformer its wound completly different to any i have seen before. it doesnt seem to have a primary "side" as it looks like both sides make the current by joining each side with the rotary switch. i think the primary side is actually inside each of the coils.
does this mean half the load of the welder goes though each of them? that would be 80 amps going though each one or doesnt it work like that? only asking because that would mean the diodes actually have a percentage of amp overhead.
fitted the caps today and what a difference it has made!
penetration seems more "consistant" and the arc is so much more stable. it no longer sounds fierce and more of a consistance sizzle
best way i can explain it!that was just with the 2 new 22000uF caps fitted so i may get some more later on.
i do have one more question though, just to help me understand it a bit more.
looking at the transformer its wound completly different to any i have seen before. it doesnt seem to have a primary "side" as it looks like both sides make the current by joining each side with the rotary switch. i think the primary side is actually inside each of the coils.
does this mean half the load of the welder goes though each of them? that would be 80 amps going though each one or doesnt it work like that? only asking because that would mean the diodes actually have a percentage of amp overhead.
shenion
Tool Pack Rat
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The primary is usually on the inside as the secondary ha sthe most heat.
If ther is just 2 diodes, then it is a half-wave bridge (center-tapped transformer.) Each diode get the current 50% of the time; or average half the current.
If ther is just 2 diodes, then it is a half-wave bridge (center-tapped transformer.) Each diode get the current 50% of the time; or average half the current.
Wedg1e
They call me Mr. Bodge-angles
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I know what you mean, that transformer design is a bit odd, it's like (well in fact it is) two transformers wound on one frame.
The primary of each is the innermost winding, each primary is rated for 110v. The selector switches connect the winding 'tappings' in series to give the various output steps. I think for 110v markets the switches would be wired to the main contactor differently but the end result would be the same. My Oxford 300 has the same circuit design and in fact has two massive copper links that can be configured for 110 or 220 mains; looking at the diagrams for both sets it'd make sense if the Romarc worked the same way.
As for the diodes, on each mains half-cycle one or other of them is conducting, but as the total current flowing in a circuit is the same wherever you measure it, then as only one diode is conducting at any time, it must be carrying the full rated current, not half of it... I think
shenion
Tool Pack Rat
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As for the diodes, on each mains half-cycle one or other of them is conducting, but as the total current flowing in a circuit is the same wherever you measure it, then as only one diode is conducting at any time, it must be carrying the full rated current, not half of it... I think
Yes, each gets the full current, but only half the time. The diodes are rated on the average current. The peak is usually several times higher.
Thanks for that info guys. it basicly gives a bit of a clue that the whole "easi-mig 160" doesnt mean this one is actually 160 amp judging by the diode ratings.
i have managed with the welder and its got me by and done the job. has been a pain here and there. Eventually i will invest in something better and up-to date.
i have managed with the welder and its got me by and done the job. has been a pain here and there. Eventually i will invest in something better and up-to date.
it's doing the job as i say. there are other issues with the welder that i recon are just down to it's age. flat spot in weld selection witch i recon is a bad wirespeed pot.
the power is there now since i changed the caps. for and some reason after a few seconds of feeding the torch vibrates, kinda like the wire is dragging or something you can feel it grinding. does it with a new tip that hasnt been used too.
it's a new liner too. very odd
