hi,
i have this Parmeko oil-filled transformer,
and i dont understand the primary windings description?
it's quite clear the secondaries are 200-150-0-150-200
but the primary is a bit confusing 0.5.90.115 ???
how do i connect for 230vac operation?
and what does this 400c/s stand for?
please help me to understand it.
best and thank you.
K
i have this Parmeko oil-filled transformer,
and i dont understand the primary windings description?
it's quite clear the secondaries are 200-150-0-150-200
but the primary is a bit confusing 0.5.90.115 ???
how do i connect for 230vac operation?
and what does this 400c/s stand for?
please help me to understand it.
best and thank you.
K
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Hello,
I am almost sure you can not use it.
The 400 means it is made for 400herzt a frequency often use if they wanna make a transformer in a small space. The same transformer usable for 50 or 60 hertz will be a lot bigger.
If you just bought it the seller should have mentioned it because it can not be used in a place were audiophiles usually live.
Normally used i think in submarines, planes.
Greetings,Eduard
I am almost sure you can not use it.
The 400 means it is made for 400herzt a frequency often use if they wanna make a transformer in a small space. The same transformer usable for 50 or 60 hertz will be a lot bigger.
If you just bought it the seller should have mentioned it because it can not be used in a place were audiophiles usually live.
Normally used i think in submarines, planes.
Greetings,Eduard
Hello,
It is cycles per second. Sometimes you also see 400hertz indicated on chokes or transformers.
I have American transformer that can be used from 50 to 1000 hertz.
USA uses 60 hertz, Europe 50 hertz in most or all countries. Can use 50 hertz in USA but the other way round it will usually heat up quickly.
Greetings,Eduard
It is cycles per second. Sometimes you also see 400hertz indicated on chokes or transformers.
I have American transformer that can be used from 50 to 1000 hertz.
USA uses 60 hertz, Europe 50 hertz in most or all countries. Can use 50 hertz in USA but the other way round it will usually heat up quickly.
Greetings,Eduard
Although the transformer may not be usable as a power transformer, quite a few diy guitar amps have used power transformers in place of output transformers. Your transformer could have a life as a valve amplifier output transformer.
The calculations and opportunities are not easy to appreciate if you don't have much experience with valve amps. The basic VA rating of the transformer appears to be about 100VA (the photo doesn't fully show the secondary rating but it looks like 290mArms winding current in FWR configuration), so the transformer could be ok in a circa 50W guitar amp.
A quick look at it indicates an 8 ohm speaker output could present a 2.1kohm PP primary impedance, by using the 90-to-115 taps of each primary connected in parallel for the speaker winding, and the primary uses the full 200-0-200V taps for a push-pull stage. That low PP primary impedance would suit line TV tubes like 6CM5/EL36, 6DQ6A and 6CD6G. Alternatively, using a 16 ohm speaker would then allow an amp to suit normal tubes like EL34, 6550, 6L6GC.
The calculations and opportunities are not easy to appreciate if you don't have much experience with valve amps. The basic VA rating of the transformer appears to be about 100VA (the photo doesn't fully show the secondary rating but it looks like 290mArms winding current in FWR configuration), so the transformer could be ok in a circa 50W guitar amp.
A quick look at it indicates an 8 ohm speaker output could present a 2.1kohm PP primary impedance, by using the 90-to-115 taps of each primary connected in parallel for the speaker winding, and the primary uses the full 200-0-200V taps for a push-pull stage. That low PP primary impedance would suit line TV tubes like 6CM5/EL36, 6DQ6A and 6CD6G. Alternatively, using a 16 ohm speaker would then allow an amp to suit normal tubes like EL34, 6550, 6L6GC.
It´s not to be used with, say, 5V source, but to provide some voltage adjustment:
115V source : 1 to 4
110V source: 2 to 4
90V source: 1 to 3
We are used to find "fine tuning" taps at the "high end", say 220-240V , or 100-110-115-120V, etc, but they work just as well at the other end (near 0V connection), all that matters is tap to tap voltage difference.
You can´t, it´s a 115V max. primary, and to boot:
400 Hz so you can´t use it on 50/60 Hz mains.
As said above, it´s quite possibly a surplus airplane transformer, where weight is critical.
There are many 110/115V ships, but there weight is not a problem, so 50/60 Hz is normal.
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Just noticed this thread ,Parmeko I know very well its transformers were high end in top British tube radios and British audio .
VERY well made so much so that the UK government awarded them military contracts ,many were potted ( fully enclosed ) ,that particular transformer I recognise and Kropka235 should NOT bin it.
Its taken from a WW2 RAF bomber so it could be worth $$$ to a British collector .
Considering a large number of Spitfires have been bought by the USA/Canada I think those US aircraft collectors might be interested .
Submarines also used them and America also used 400Hz or cycles as the old term was named .
Also fitted to military aircraft were battery powered ( input ) motorised frequency convertors/generators , one guy I knew ran a 400Hz communications receiver with one ---it was a bit noisy of course
There is a whole list of reasons why they were used including powering airborne communications equipment etc.
I actually had one of them taken from a WW2 aircraft communications unit , it also had transmitting tunable capacitors of several 1000 volts insulation using ceramics and wider spacing vanes --try buying one now at £1 or two as they cost way back then.
VERY well made so much so that the UK government awarded them military contracts ,many were potted ( fully enclosed ) ,that particular transformer I recognise and Kropka235 should NOT bin it.
Its taken from a WW2 RAF bomber so it could be worth $$$ to a British collector .
Considering a large number of Spitfires have been bought by the USA/Canada I think those US aircraft collectors might be interested .
Submarines also used them and America also used 400Hz or cycles as the old term was named .
Also fitted to military aircraft were battery powered ( input ) motorised frequency convertors/generators , one guy I knew ran a 400Hz communications receiver with one ---it was a bit noisy of course
There is a whole list of reasons why they were used including powering airborne communications equipment etc.
I actually had one of them taken from a WW2 aircraft communications unit , it also had transmitting tunable capacitors of several 1000 volts insulation using ceramics and wider spacing vanes --try buying one now at £1 or two as they cost way back then.
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