Try this :
WinZip - Free software downloads and software reviews - CNET Download.com
or that:
Welcome to ZipGenius.com - ZipGenius.com
and have fun.
Yves.
WinZip - Free software downloads and software reviews - CNET Download.com
or that:
Welcome to ZipGenius.com - ZipGenius.com
and have fun.
Yves.
I strongly recommend against using wire removed from motors or transformers for winding anything with the potential of drawing high currents, due to very probable short circuit conditions in the winding. Even modern wire can be scraped to bare copper by the physical process of removing it from bobbins and stators. In addition, if the transformer or motor has been through a heat cycle that exceeded the temperature rating of the insulation, you WILL suffer a failure in a relatively short time period. Adding high voltage to the equation, with, the corona problems inherent, will guarantee a short, smoky, smelly life cycle.
Even wire you just put on a bobbin and then removed is no longer suitable for high voltage windings. Corona starts it's insulation destruction at 30 vac rms, but the real damage begins at around 100vac rms. Corona attacks any dielectric discontinuity, like stress fractures in the coating of wound and subsequently straightened and rewound wire.
Copper wire base price has climbed 500% in the last three years. Core prices have climbed 1700% for M6, somewhat less for lower grades and we have seen about a 20% drop in all grades just recently.
Bud
I wish. The per ton additional price has increased from $57 per in 2001 to $550 per ton in April of 2010 and has fallen back to $350 per ton for April of this year. That is the raw material add on. The actual price, with new minimums in place (typically 80 to 200 pounds) and surcharges for less than one ton of material and the freight now charged from the mid west to the west coast, that was not charged until 2008, well, just over 10 times the price when landed at our door. Makes C cores ever more attractive in price. Now, if I could get three nested J core cuts, out of a wound tape core with the center nest reversed, I would change in a heart beat.
Transformers winding
Hello!
I am a coil winder located in Athens, Greece. I have just posted a thread, you can visit it at http://www.diyaudio.com/forums/tubes-valves/185956-my-little-801a-power-amplifier.html
If you think you would need any assistance, feel free to contact me.
Best regards,
P. Avgeris
Hello!
I am a coil winder located in Athens, Greece. I have just posted a thread, you can visit it at http://www.diyaudio.com/forums/tubes-valves/185956-my-little-801a-power-amplifier.html
If you think you would need any assistance, feel free to contact me.
Best regards,
P. Avgeris
For those of us not absolutely opposed to EI cores, this company had reasonable prices and no mininum order, though it has been a while since I was in communication with them. They preferred to communicate by email, if I remember correctly.
Lamination Specialties - Home
I would be interested in how it goes if any of you contact them.
Lamination Specialties - Home
I would be interested in how it goes if any of you contact them.
Usually I am ordering two types of cores, one for all power supplies and one for signal transformers. I never use E I laminations because the sonic results are poor to my ears (all else being equal of course). I only use C Cores for both power and signal transformers.
The cores I'm using for power supplies are CRGO 0.23mm maximum (0.1-0.23mm) where the signal transformers are made of a proprietary magnetic material, ordered to a factory in Far East in considerable quantities, with much tremendously increased cost.
IMHO it is of no use dismantling old transformers to take out their iron. I know several guys in Russia and S. Korea that use old iron made by Western Electric or Telefunken to wind their transformers. Cores made of most modern magnetic materials, if implemented correctly, give best results.
For anybody who would like to get involved in transformers winding techniques, there is much info spread around, but it will take some years before the results are up to the best of the commercial products. Can you make better trannies than say Tango or Tamura? By all means YES, but it will take several years to master.
The cores I'm using for power supplies are CRGO 0.23mm maximum (0.1-0.23mm) where the signal transformers are made of a proprietary magnetic material, ordered to a factory in Far East in considerable quantities, with much tremendously increased cost.
IMHO it is of no use dismantling old transformers to take out their iron. I know several guys in Russia and S. Korea that use old iron made by Western Electric or Telefunken to wind their transformers. Cores made of most modern magnetic materials, if implemented correctly, give best results.
For anybody who would like to get involved in transformers winding techniques, there is much info spread around, but it will take some years before the results are up to the best of the commercial products. Can you make better trannies than say Tango or Tamura? By all means YES, but it will take several years to master.
Can anyone recommend a good fixative to spray or brush on the windings when you finish a layer. I have noticed most commercial transformers do not use end boards to capture the winding so them must be glued in place.
Varnish or polyurethane are two choices that come to mind or old fashion rosin. All of which dry quickly with a hair dryer.
The core laminate supplier posted earlier has some good prices on 1000 piece stacks. I thank you for that direction.
Tad
Varnish or polyurethane are two choices that come to mind or old fashion rosin. All of which dry quickly with a hair dryer.
The core laminate supplier posted earlier has some good prices on 1000 piece stacks. I thank you for that direction.
Tad
A rookie tale.
I’ve got a pair of Quad ESL-63 double C-core transformers that will one day (hopefully) be converted to a pair of 1.5K transformers for an EL84-in-parallel amp (Broskie’s five-per-channel EL84 ‘the simplest possible’ amp). Each double C is 48mm wide, 58mm tall and 50mm deep, made of very thin laminations (13mm ‘leg’ thickness). Why 1.5K? Well, to acquaint myself with winding transformers I started with a layered choke. Two hours later: aching back, dozens of @#$%^&! words and with a mess of a choke I gave up… I continued the following day with much more patience. The choke was fine this time around, but it took almost 4 hours (of hand winding it)!!! Right there and then I realized that, when everything’s put in perspective, all those expensive OPTs are not really expensive… Originally I wanted to use the Quad cores to wind a pair of 5K OPTs but when I calculated the 1) cost of wire and all other accessories 2) time needed to wind all those thousands of turns 3) my almost complete absence of practical know-how – well, I decided to try a lower load… Less turns plus thicker wire should theoretically equal something attainable. Still, I’m in no hurry or, translated – presently I don’t have the courage to try a real OPT… On the other hand, being a DIY by nature - I just have to try it one day…
By the way, I managed to salvage the coils from the above mentioned transformers. Each one measures 3.12KOhms DCR. Can they be used for something, anything instead of being discarded?
I’ve got a pair of Quad ESL-63 double C-core transformers that will one day (hopefully) be converted to a pair of 1.5K transformers for an EL84-in-parallel amp (Broskie’s five-per-channel EL84 ‘the simplest possible’ amp). Each double C is 48mm wide, 58mm tall and 50mm deep, made of very thin laminations (13mm ‘leg’ thickness). Why 1.5K? Well, to acquaint myself with winding transformers I started with a layered choke. Two hours later: aching back, dozens of @#$%^&! words and with a mess of a choke I gave up… I continued the following day with much more patience. The choke was fine this time around, but it took almost 4 hours (of hand winding it)!!! Right there and then I realized that, when everything’s put in perspective, all those expensive OPTs are not really expensive… Originally I wanted to use the Quad cores to wind a pair of 5K OPTs but when I calculated the 1) cost of wire and all other accessories 2) time needed to wind all those thousands of turns 3) my almost complete absence of practical know-how – well, I decided to try a lower load… Less turns plus thicker wire should theoretically equal something attainable. Still, I’m in no hurry or, translated – presently I don’t have the courage to try a real OPT… On the other hand, being a DIY by nature - I just have to try it one day…
By the way, I managed to salvage the coils from the above mentioned transformers. Each one measures 3.12KOhms DCR. Can they be used for something, anything instead of being discarded?
Nice tale fullrange!
It has always amused me to watch customer companies decide that their transformers are just to d%!n expensive (usually 1/2 of all material costs for just the OPT's) and embark upon "making their own". Never occurs to them to ask we who are foolish enough to be lodged in this industry, just what our profit margins might actually be. As an industry, we make the grocery industry look highly profitable.
And when you wander off to China, where they work very hard and have many clever and skilled people in the work force, you find not enough middle class middle management supervisors. So you end up with very inexpensive transformers, where a critical piece of tape was not applied and the things fail at a 100% rate. And yet, the rest of the construction is first class in workmanship. The point being just what you have discovered, the grass always looks greener where you cannot see the bare patches.
Incidentally, we take one hour to wind one 10 interleave Out Put coil and one hour and forty five minutes to wind a 16 interleave coil, for our level three OPT's. So, your times are not out of the ordinary!
Bud
It has always amused me to watch customer companies decide that their transformers are just to d%!n expensive (usually 1/2 of all material costs for just the OPT's) and embark upon "making their own". Never occurs to them to ask we who are foolish enough to be lodged in this industry, just what our profit margins might actually be. As an industry, we make the grocery industry look highly profitable.
And when you wander off to China, where they work very hard and have many clever and skilled people in the work force, you find not enough middle class middle management supervisors. So you end up with very inexpensive transformers, where a critical piece of tape was not applied and the things fail at a 100% rate. And yet, the rest of the construction is first class in workmanship. The point being just what you have discovered, the grass always looks greener where you cannot see the bare patches.
Incidentally, we take one hour to wind one 10 interleave Out Put coil and one hour and forty five minutes to wind a 16 interleave coil, for our level three OPT's. So, your times are not out of the ordinary!
Bud
I am not fast Tony. The women who made 75,000 power transformers for Mackie Designs first mass market mixer are the fast ones. 7 windings, 90% build, operating at 121 deg C in the mixer, utilizing metalwork that had been heat treated to Osteonite temp to provide -40 db of field suppression. Then they embalmed that in an M6 sheet stock sarcophagus to obtain the next -60db down.
With the approaching end of our careers in this odd industry my CEO / wife and I have reduced our production to a few fairly small OEM accounts for commercial power and a few Guitar Amplifier companies, like THD, Soldano, Fortin, Anderson, Club and Rhodes. We also supply the SLO clone market through our distributor, C3 amps. We will likely be finished with this part of our lives in 3 to 4 years, assuming our health lasts to our 70's.
I can rarely make two of anything to the same level. I can do all of the activities needed with a high level of skill, but I don't deal with repetitive actions well.
Bud
With the approaching end of our careers in this odd industry my CEO / wife and I have reduced our production to a few fairly small OEM accounts for commercial power and a few Guitar Amplifier companies, like THD, Soldano, Fortin, Anderson, Club and Rhodes. We also supply the SLO clone market through our distributor, C3 amps. We will likely be finished with this part of our lives in 3 to 4 years, assuming our health lasts to our 70's.
I can rarely make two of anything to the same level. I can do all of the activities needed with a high level of skill, but I don't deal with repetitive actions well.
Bud
Neither do I
When people ask how much the discount is for X pieces, I usually say that a series production will be more expensive than a single pair; I am not a machine.
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