AnTec Power Transformer spec Help Pleas

[colin.hepburn]

Hi All
Ok as the UK and the US have different mains voltages
US are at 120 volts and UK is at 230/240? Volts my mains is always @ 240volts
My Problem is the AnTec Transformer spec my intended TX is the AS-4T400
Outputs 4x
Power 400VA
Output Voltage Current
400V 0.5A
400V 0.5A
6.3V 4A
6.3V 4A

But this spec it for the US mains 120 voltages @60Hz so using this TX on UK 240 volts @50Hz the current would be cut in half i.e. 400v @0.25A on each winding and 2.Amps on each 6.3v heater winding is this correct

http://www.antekinc.com/details.php?p=712

[pre65]

But this spec it for the US mains 120 voltages @60Hz so using this TX on UK 240 volts @50Hz the current would be cut in half i.e. 400v @0.25A on each winding and 2.Amps on each 6.3v heater winding is this correct

http://www.antekinc.com/details.php?p=712

Same spec for 120v or 240v Colin.

I'm sure you have asked this question before and got the same answer.

Even if you use it as 400-0-400 (windings in series) the current will still be 0.5A (500ma) which is more than you are ever likely to need.

In fact, if you use it as 400v ( both 400v windings in parallel) you will get 400v at 1A.

Have you ordered one, or a pair ?

[colin.hepburn]

But this spec it for the US mains 120 voltages @60Hz so using this TX on UK 240 volts @50Hz the current would be cut in half i.e. 400v @0.25A on each winding and 2.Amps on each 6.3v heater winding is this correct

http://www.antekinc.com/details.php?p=712

Same spec for 120v or 240v Colin.

I'm sure you have asked this question before and got the same answer.

Even if you use it as 400-0-400 (windings in series) the current will still be 0.5A (500ma) which is more than you are ever likely to need.

In fact, if you use it as 400v ( both 400v windings in parallel) you will get 400v at 1A.

Have you ordered one, or a pair ?

Hi Philip
Yes you're right I have kinda asked this question before But I have came across the spec sheet for my old small Hammond TX which I used in my headphone amp which is causing me the confusion this TX gives the spec for US and UK voltages

The TX I am referring to is the 229B230 last one on the list which give the spec as 230v CT@50mA and 120v @ 100mA there lies my confusion on this subject
but maybe I am missing something I just don't get transformers specs http://www.hammondmfg.com/pdf/229Insert.pdf

I am await a reply from john on restocking he said the 20th so maybe next week I hope just ordering one for know
and i am just waiting for the set of four damper diodes to come 17 days now

[pre65]

Yes you're right I have kinda asked this question before But I have came across the spec sheet for my old small Hammond TX which I used in my headphone amp which is causing me the confusion this TX gives the spec for US and UK voltages

The TX I am referring to is the 229B230 last one on the list which give the spec as 230v CT@50mA and 120v @ 100mA there lies my confusion on this subject
but maybe I am missing something I just don't get transformers specs http://www.hammondmfg.com/pdf/229Insert.pdf

That Hammond spec refers to the secondary windings in either series or parallel configuration.

With two equal secondaries series connection gives 2 X voltage and parallel connection gives 2 X current.
So if that Hammond has two 115v @ 50ma secs, connecting in series IS 230v @ 50ma (double the volts) and connecting in parallel IS 115v @ 100ma (double the current). That is the same whether the primary is wired for 115v or 230v.

Is it starting to make sense ?

[Cressy Snr]

IS 115v @ 50ma (double the current). That is the same whether the primary is wired for 115v or 230v.

Is it starting to make sense ?

You mean 100mA? don't you Phil

[pre65]

IS 115v @ 50ma (double the current). That is the same whether the primary is wired for 115v or 230v.

Is it starting to make sense ?

You mean 100mA? don't you Phil

Mia culpa.

Glad to see you are awake Steve and checking up on me. I've amended the errant figures.

[colin.hepburn]

Yes you're right I have kinda asked this question before But I have came across the spec sheet for my old small Hammond TX which I used in my headphone amp which is causing me the confusion this TX gives the spec for US and UK voltages

The TX I am referring to is the 229B230 last one on the list which give the spec as 230v CT@50mA and 120v @ 100mA there lies my confusion on this subject
but maybe I am missing something I just don't get transformers specs http://www.hammondmfg.com/pdf/229Insert.pdf

That Hammond spec refers to the secondary windings in either series or parallel configuration.

With two equal secondaries series connection gives 2 X voltage and parallel connection gives 2 X current.
So if that Hammond has two 115v @ 50ma secs, connecting in series IS 230v @ 50ma (double the volts) and connecting in parallel IS 115v @ 100ma (double the current). That is the same whether the primary is wired for 115v or 230v.

Is it starting to make sense ?

I see what you're saying Philip but it isn't any clearer really the way I see it is if you are using the TX on a 120v supply looking at the Hammond 229230 120v is 100mA and running it on 230v is 50mA high voltage lower current

I'm sure I have seen something about this somewhere before
And my other concern about the AnTec TX
Is the 230v primary as UK voltage is more than the states 230v in most areas we are at risk of core saturation as I think Paul pointer out on here somewhere maybe this is not a concern but will still change things shoving 240 volts though a 230v TX

I think I need to get Morgan Jones book out again anyone have any good beginners links to this very subject on Mains TXs

[pre65]

I see what you're saying Philip but it isn't any clearer really the way I see it is if you are using the TX on a 120v supply looking at the Hammond 229230 120v is 100mA and running it on 230v is 50mA high voltage lower current

You are getting confused between the primary and the secondary.

IT MAKES NO DIFFERENCE RUNNING THE PRIMARY ON 115V (USA) OR 230v (UK).

[Cressy Snr]

I see what you're saying Philip but it isn't any clearer really the way I see it is if you are using the TX on a 120v supply looking at the Hammond 229230 120v is 100mA and running it on 230v is 50mA high voltage lower current

I'm afraid Phil is right Colin.

When a transformer steps down a voltage it steps up the current at the secondary.
You need to stop thinking about voltage and current and start thinking in terms of power instead.

When a transformer does its transforming, ignoring losses due to heating of the copper coils and a few other bits, the power you put into the primary has to come out at the secondary, otherwise we would be defying the laws of physics, specifically energy conservation ie energy cannot be created or destroyed, only changed from one form to another.

Therefore looking at your 120V at 100mA that's 12 watts you can put in at the primary.
Now look at 230V at 50mA, thats still 12 watts you can put in at the primary.

So if these are isolation transformers, which judging by the specs they look to be, that means that the primaries are probably the same as the secondaries, either 115V (parallel the primaries for the USA) or 230V primaries in series in the UK.

It is still 12W in and 12W out.
The secondaries will draw current according to what you have on the ends of them.

If you have the 230V series wiring on the primary side and you connect series wired secondaries to something that draws 100mA there will be smoke and a horrible smell, because you have just tried to draw 24W of power from a transformer rated for 12W.

You can only draw 100mA with your secondaries parallelled (115V) if you have the primaries in series. Because then the transformer is stepping the voltage down and the current up, which brings us back to equilibrium.

You can't have both sets in series and draw 100mA, which the spec makes clear.

Regarding the Antek transformers you were referring to at the beginning

Look at the VA rating (that's Watts to us simple folk)

Right....the secondaries will put out 400W of power into the HT line to feed whatever is drawing on them.

So... the primary must supply that 400W or it defies the laws of physics.
If the primaries are wired in parallel they draw their 400W from the USA mains at a certain current (they can't do anything else if the secondary is drawing that power level.

If the primaries are in series (UK) the primary still has to draw 400W cos thats what the secondaries are demanding but in series the step down ratio is double that of the USA connection.


Soooooo. If the step down ratio is double then the higher electromotive force from the UK mains (voltage to us simple folk) will cause the transformer primary to draw only half the current that the USA connection would have done, but still allow the secondary to provide the 400W that the circuit is asking for.

It is this doubling of the step-down ratio from US to UK spec that allows us still to draw 400W from the wall socket whatever country we live in, and the transformer will not burn out.
As Scotty would say " its the laws of physics Jim, ye cannae change them"
Does that make any more sense.

[colin.hepburn]

Thanks for the Lesion Steve and Phillip
I wasn't saying Philip was wrong by any means
I just seem to be stuck on this confusion with the way TXs are rated by the difference countries like UK /US and Germany which started all this off when my Ask Jan TX burned out

All I want to do when buying a TX is to know what secondary Voltage I want and important the current I need and basically forget about it

Example if I have a TX of 400v and I need a current of say 150/200mA I want the TX to be well over rated and give me the required 400/450v but say double the current at 500mA as I don't want to have a repeat of the Ask Jan TX saga and won't have to worry about what current I draw from it with other amp

I need to know I have something like twice the current in reserve as I am using to be happy about it

[pre65]

Don't worry Colin. That Antek will be more than man enough for what you need.

Andrew I is going to run two 833a (GU_48) from one 360-0-360 Antek (to start with) and it will cope with them.

[andrew Ivimey]

I'm expecting it may get toasty warm after a while though

[colin.hepburn]

Hi All
Right I have received my AnTek AS-4T360 today looks good
But wiring is a little confusing so can anyone who has this AS-4T360 TX confirm the wiring for it
1. Mains side
Connect centre RED/BLACK together for 230volts
2. Main side also has a static shield wire is this wire connected to chassis of left unconnected
3. Secondary side for 360v CT
4. Connect YELLOW 0v /White 360v FOR.CT 360-0-360V
5. What is the function on the 70v winding and how is this used
Is this Correct See wiring Diagram?
Thanks

[pre65]

Hi Colin, mine don't have the 70v tap, but it would be useful if you needed to go fixed bias for the output valve.

The 70v winding could provide a positive (for class A2), or negative (for class A1) bias supply depending how you wire it up.

[colin.hepburn]

Hi Colin, mine don't have the 70v tap, but it would be useful if you needed to go fixed bias for the output valve.

The 70v winding could provide a positive (for class A2), or negative (for class A1) bias supply depending how you wire it up.

Hi Philip
Thanks
Right the 70v tap is unused for now then so I tie it up out of the way for later use we can come back to this when required
Still need to confirm if
Q4. Connect YELLOW 0v /White 360v together FOR.CT 360-0-360V is this correct and
Q2 Main side also has a static shield wire is this wire connected to amp chassis or left unconnected