Hi Samoloko,
I only have what is posted on the list. I have several transformers suitable for 240V mains, but they're not made by Plitron. Anything with "240" listed under the heading "Primary" would work for you.
Several of the ATC Frost transformers have potted cores, and are quite well made. T45 would likely work for your application.
Buying a brand new transformer that is a "Lono" version and fully potted would likely cost upwards of $300 so there aren't too many around. Luckily, you can do a lot of simple things yourself that will get you there without spending that kind of money.
Let me know if anything on the list is of interest to you.
KOA,
I sent you a note... T1 is still available.
Cheers,
Owen
I only have what is posted on the list. I have several transformers suitable for 240V mains, but they're not made by Plitron. Anything with "240" listed under the heading "Primary" would work for you.
Several of the ATC Frost transformers have potted cores, and are quite well made. T45 would likely work for your application.
Buying a brand new transformer that is a "Lono" version and fully potted would likely cost upwards of $300 so there aren't too many around. Luckily, you can do a lot of simple things yourself that will get you there without spending that kind of money.
Let me know if anything on the list is of interest to you.
KOA,
I sent you a note... T1 is still available.
Cheers,
Owen
Hi tool49,
Both T9 and T10 are still available, but I have no way to contact you. I might also be driving through to Vermont this weekend, so there's a possibility I can drop them off in Montreal if it's not too far out of the way.
Let me know if you're still interested.
The following transformers are now sold:
T32
T33
T44
I will be re-formatting the list in the next day or two, and eliminating the transformers that have sold to make like easier.
Cheers,
Owen
Both T9 and T10 are still available, but I have no way to contact you. I might also be driving through to Vermont this weekend, so there's a possibility I can drop them off in Montreal if it's not too far out of the way.
Let me know if you're still interested.
The following transformers are now sold:
T32
T33
T44
I will be re-formatting the list in the next day or two, and eliminating the transformers that have sold to make like easier.
Cheers,
Owen
Hi Guys,
As promised I've made an updated list with only the toroids left for sale.
From now on I'll be posting the number of anything that sells in future posts, and when the list gets too confusing I'll update it again.
Looks like the first group of people have received their toroids, and so far feedback has been great.
As a side note, I'll be in Vermont this weekend, so please be patient with e-mail replies. I may not be able to get back to anyone until Sunday night.
Cheers,
Owen
As promised I've made an updated list with only the toroids left for sale.
From now on I'll be posting the number of anything that sells in future posts, and when the list gets too confusing I'll update it again.
Looks like the first group of people have received their toroids, and so far feedback has been great.
As a side note, I'll be in Vermont this weekend, so please be patient with e-mail replies. I may not be able to get back to anyone until Sunday night.
Cheers,
Owen
If you use the transformer at 1/2 voltage on primary you also get 1/2 voltage on secondary. Keep in mind it is the primary to secondary turns ratio(as well as input Voltage) that sets the secondary voltage.
I f the primary has 2 sets of 110 voltage then they may be wired in Paralell or series but it looks like the T6 has only one winding for primary.
I f the primary has 2 sets of 110 voltage then they may be wired in Paralell or series but it looks like the T6 has only one winding for primary.
Understood, and I thought the same, there is one one primary winding.
Maybe I misinterpreted this quote from Own:
Thanks!!
Maybe I misinterpreted this quote from Own:
So I assumed the secondary voltage in the pdf is what I would see in the 120VAC land. The secondary number is doubled in the 240VAC world. Use T6 as example, the true spec is probably 240VAC primary, 38-0-38 secondary, 700VA. But if I use it as a 120/19-0-19, I can only use it as 350VA rated (maybe a little higher due to it is for 50hz). In other words, if I need a 700VAC 19-0-19 to use in US, T6 is not the right one. It can be quite costly to buy a wrong toroid
Thanks!!
OK I missed or forgot that part about testing at 120.
You are right about the 50Hz should give you about more power reserve as inductance is not resistance loss.
I recall there is a writeup at PLitron about the losses in windings and core.
You might consider these factors as well.
So there may be a further increase in power output as the loss in the core is also part of the maximum dissipation. I do not remember the proportions of the losses.
Also the primary windings are 2x over-engineered. as far as current is considered.
I would think regulation would end up being better also.
You are right about the 50Hz should give you about more power reserve as inductance is not resistance loss.
I recall there is a writeup at PLitron about the losses in windings and core.
You might consider these factors as well.
So there may be a further increase in power output as the loss in the core is also part of the maximum dissipation. I do not remember the proportions of the losses.
Also the primary windings are 2x over-engineered. as far as current is considered.
I would think regulation would end up being better also.
Hi SheldonD and pchw,
You guys are both mostly correct, but as Sheldon said, the copper losses are only part of the equation. If you run a 240V transformer on 120V you do double the current in the primary and secondary, which in turn doubles the copper losses. Core size, and core losses are a big part of the equation too. You'd have to chop up a transformer and figure out the wire size used on the primary and secondary, then figure out the A/mm^2 you're comfortable with and sort out the VA from there.
I can't say for sure with any of these transformers, but they're likely not VA limited based on copper losses, which means you certainly wouldn't have to halve the VA rating when used at 120V. The fact that they were designed for 50Hz use also means that they're 10-20% over what would be needed at 60Hz.
Just the same, it should be clear that the parts listed with 240V primaries are indeed 240V transformers, and all the voltages stated in the list are with 120V input. As far as de-rating the VA, I'll leave that up to the individual buying the parts. There is a hilarious tendency on this site to badly over-buy when it comes to transformer VA, so I'm pretty sure nobody has anything to worry about. The fellow looking for a 250VA transformer for a 20w/ch chip amp is a perfect example of the overkill I'm talking about. With a decent size cap he could get away with a 50VA transformer and still be over-doing it.
On that note, if you're building a class A amp that draws 700 watts, then buying a 240V 700VA toroid and running it on 120V is probably not wise. Please plan accordingly.
I'm in Vermont now and managed to drop off a few toroids to a couple of fellow audio junkies in Quebec along the way. It's always great to meet people face to face and see what it is they're doing with the giant pieces of copper and iron I'm selling. I'll answer all emails tomorrow night.
Enjoy your weekend, and feel free to contact me with any questions.
Cheers,
Owen
You guys are both mostly correct, but as Sheldon said, the copper losses are only part of the equation. If you run a 240V transformer on 120V you do double the current in the primary and secondary, which in turn doubles the copper losses. Core size, and core losses are a big part of the equation too. You'd have to chop up a transformer and figure out the wire size used on the primary and secondary, then figure out the A/mm^2 you're comfortable with and sort out the VA from there.
I can't say for sure with any of these transformers, but they're likely not VA limited based on copper losses, which means you certainly wouldn't have to halve the VA rating when used at 120V. The fact that they were designed for 50Hz use also means that they're 10-20% over what would be needed at 60Hz.
Just the same, it should be clear that the parts listed with 240V primaries are indeed 240V transformers, and all the voltages stated in the list are with 120V input. As far as de-rating the VA, I'll leave that up to the individual buying the parts. There is a hilarious tendency on this site to badly over-buy when it comes to transformer VA, so I'm pretty sure nobody has anything to worry about. The fellow looking for a 250VA transformer for a 20w/ch chip amp is a perfect example of the overkill I'm talking about. With a decent size cap he could get away with a 50VA transformer and still be over-doing it.
On that note, if you're building a class A amp that draws 700 watts, then buying a 240V 700VA toroid and running it on 120V is probably not wise. Please plan accordingly.
I'm in Vermont now and managed to drop off a few toroids to a couple of fellow audio junkies in Quebec along the way. It's always great to meet people face to face and see what it is they're doing with the giant pieces of copper and iron I'm selling. I'll answer all emails tomorrow night.
Enjoy your weekend, and feel free to contact me with any questions.
Cheers,
Owen
Recieved both Piltrons a few weeks ago, only was able to get to it a few nights ago...looks good...Thanx - I have always read how Piltrons were the Cat's Pajamas...
I noticed that the Piltrons I have (29-0-29 590VA) are smaller/weigh less than what I thought they would be...
For instance I have a Antek 22-0 22-0 400VA that weigh about 30 - 40% more than the Piltron...it is potted tho....
Please don't get me wrong, I am more than happy with the purchase, but is this normal?
I noticed that the Piltrons I have (29-0-29 590VA) are smaller/weigh less than what I thought they would be...
For instance I have a Antek 22-0 22-0 400VA that weigh about 30 - 40% more than the Piltron...it is potted tho....
Please don't get me wrong, I am more than happy with the purchase, but is this normal?
Hi John,
Glad to hear everything got to you safely! As for the size/weight thing, it's a bit of a toss up. The VA rating depends on the core material/shape/quality, the copper area, temp rise, regulation and a bunch of other things. I have a few Antek transformers in some tube amps, and they're also physically larger than their VA would imply.
You'd have to do a side by side comparison to check for vibration, noise, heat, and regulation under similar loads to really see which of the two are best.
Cheers,
Owen
Glad to hear everything got to you safely! As for the size/weight thing, it's a bit of a toss up. The VA rating depends on the core material/shape/quality, the copper area, temp rise, regulation and a bunch of other things. I have a few Antek transformers in some tube amps, and they're also physically larger than their VA would imply.
You'd have to do a side by side comparison to check for vibration, noise, heat, and regulation under similar loads to really see which of the two are best.
Cheers,
Owen
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