Is a transformer a transformer?

[sjrixon]

I'm plotting my 'power station' for my layout. Seeing plans on here make me think this is a really good idea! Transformer, CDU, maybe a relco, all in one box that I can connect to any layout.

 

So, transformers.. The gaugemaster ones are about £18..

 

http://www.ehattons.com/7180/Gaugemaster_Controls_T1_Uncased_2_x_16V_AC_Transformer/StockDetail.aspx

 

But online you get something that appears very similar for a lot less money..

 

http://www.brimal.co.uk/index.php/online-shop?page=shop.product_details&flypage=eny_fly_brimal.tpl&product_id=1223&category_id=503

 

I'm sure it's a question of taste, but one of those a couple of 1.6a breakers from Maplin  http://www.maplin.co.uk/p/16a-auto-reset-circuit-breaker-ak08jI'm well on my way for a nice price!

[leopardml2341]

Hold on there.........

 

Some reasons why they aren't the same and flaws with your proposal......

[Grovenor]

Those are only 6VA per winding which is not enough power for most model railway applications.

What are you expecting to run with it?

Keith

[leopardml2341]

The Hattons item is a transformer that will provide 1.25A at 16v - more correctly 20VA.

 

The only item is only a 12v output providing 6VA or Approx 0.5 A

 

The circuit breakers you have selected from maplin are over rated by 40% for the Hattons item and 300+% for the online item.

 

In summary:

 

For both transformers the cb does not give appropriate [protection and in th case of the online item could cause a fire.

The output from each will need to rectified and for the online item that means you won't get 12v dc.

 

PM me with your specifics and I'll try to assist.

[Crosland]

The Gaugemaster from hattone is 2x16Vx1.25A or 40VA (volt-amps or voltsxamp or, for our purposes, power).

 

The other one doesn't make it clear whether the 6VA is per winding or total. Either way it is only good for a lot less current than the Gaugemaster one, and the 1.6A breakers will be useless.

 

Any circuit breaker should be rated less than the upstream supply. Think of your mains house wiring where you you have something like a 60A fuse before the consumer unit, then 30A fuses for each ring main in the consumer unit, then up to 13A in each plug top and finally much smaller fuses in the equipment itself.

 

Andrew

[leopardml2341]

Electricity, can't see it, can't smell it CAN feel it (sometimes fatally) - but very dangerous.

 

If in doubt - ask, don't experiment.

[Danemouth]

Electricity, can't see it, can't smell it CAN feel it (sometimes fatally) - but very dangerous.

 

If in doubt - ask, don't experiment.

 

Absolutely right Andy, caution is the watchword where mains electricity is concerned.

 

http://www.rmweb.co.uk/community/index.php?/topic/96233-mains-power-supplies-for-analogue-model-railways/

 

My advice is to stick with the Gaugemaster stuff that is designed specifically for model railways.

 

Regards,

 

Dave

[sjrixon]

So if the gaugemaster is 1.26A. 1.0A circuit breakers are the way to go?

 

http://www.maplin.co.uk/p/10a-auto-reset-circuit-breaker-ak07h

[Junctionmad]

http://www.brimal.co.uk/index.php/online-shop?page=shop.product_details&flypage=eny_fly_brimal.tpl&product_id=1228&category_id=503 would be close to the Gaugemaster one, Theres nothing special about the gauge master  transformer, just be sure you know what you are doing in all cases 

[Crosland]

My advice is to stick with the Gaugemaster stuff that is designed specifically for model railways.

 

The Gaugemaster transformer is a completely bog standard transformer. The only model railway specific things about it are the suppliers name and the price.

 

Andrew

[Titan]

A thermal cut out like the old Hammant and Morgan transformers had might be a better bet. It won't trip if you have a brief overload, like if you happen to switch a lot of points whilst powering something else, and would still give adequate protection.

[kevinlms]

Have you had a read of this 'sticky' thread?

 

http://www.rmweb.co.uk/community/index.php?/topic/96233-mains-power-supplies-for-analogue-model-railways/

 

Some of your questions, suggest that you perhaps ought to consider purchasing a ready made unit, rather than mess about with 240 Volt equipment. It is dangerous in the wrong hands. Not knowing the difference between the meaning of 1.25 Amps (Gaugemaster) & 6VA of another brand, more than hints that you don't really know what you're dealing with.

 

Zapping yourself, is no good way of saving a few quid.

[sjrixon]

Sticky yes... I know enough to be dangerous..  .. But yes It's been a while.. I'm a little rusty.

 

The second transformer was 2x15v 50VA.. So unless my knowledge has really gone to pot then it's 50/15 which is 3.3amps over the pair. So you would 'guess' about 1.5 per output, on par with the gaugemaster one. I'd linked the wrong one in my first post, I'd meant to link the 15v version. However that's nearly the same price as the known gaugemaster one, so not quite the saving I initially thought. 

[Suzie]

Very few applications nowadays require AC which means that you can avoid messing about with big, heavy, expensive, (and in the case of open frame potentially dangerous for the unwary)  transformers.

 

If you can make use of DC something like a ready made switchmode PSU will make life a lot easier and use less power.

 

Which things require AC? off the top of my head only a few motorized accessories and the Lenz LS150 accessory decoder.

 

Most CDUs can be run happily from a suitable DC supply.

[sjrixon]

I'm powering a Gaugemaster HH so needs to be AC. Just trying to play out the options as it's been a while ☺

[brianusa]

All these tales of transformers and fuses, etc, are very interesting.  As a tinplater with a room size layout, I run old Lionel transformers that are around fifty or sixty years old.  They still have the same two pin plugs and original flex and power points an accessories on the layout.  This includes twenty points with associated bulbs and various lights in accessories.  The actual running is by more modern means, a solid state MTH dual transformer capable of 24VAC which runs two circuits and a nine car illuminated passenger train draws about 5A or more.   PAT testing is unheard of over here but you don't hear of any layouts going up in flames.

 

Brian.

[Suzie]

I am not familiar with the HH, but I suspect that it will work just as well on DC.

[CourthsVeil]

Afraid, Suzie, but in this case you are wrong.

Indeed the Gaugemaster HH requires AC. But surely it doesn't need 50VA, rather 16V @ 1.25A.

 

What – apart from the train – are you to power with your 'power station' ?

 

BTW I fully agree with what has been said in post #12...

 

Sorry

   Armin

 

 

 

edit: 1st sentence added

[sjrixon]

Thanks for all the help on this one.. 

 

I just want to build a unit with a transformer, connecting to a CDU and the Gaugemaster handheld. Then I can use this for any layout, rather than building them into a control panel. I've done this before (Having stripped a H&M for the transformer) but just wanted to confirm and check a few bits and I had read some contradictory information on the web (no really ).

 

I'm going to stick with the gaugemaster, add some thermal cut outs and be very safe

[leopardml2341]

Thanks for all the help on this one.. 

 

I just want to build a unit with a transformer, connecting to a CDU and the Gaugemaster handheld. Then I can use this for any layout, rather than building them into a control panel. I've done this before (Having stripped a H&M for the transformer) but just wanted to confirm and check a few bits and I had read some contradictory information on the web (no really ).

 

I'm going to stick with the gaugemaster, add some thermal cut outs and be very safe

Don't forget to let us all know how you get on ?

[sjrixon]

Will do.. Don't hold your breath though, these things take time..

[Crosland]

The second transformer was 2x15v 50VA..

 

Look at the link again

[leopardml2341]

Look at the link again

 

I thought same as you at first, but see below - same post, second paragraph, fourth sentence.

 

Sticky yes... I know enough to be dangerous..   .. But yes It's been a while.. I'm a little rusty.

 

The second transformer was 2x15v 50VA.. So unless my knowledge has really gone to pot then it's 50/15 which is 3.3amps over the pair. So you would 'guess' about 1.5 per output, on par with the gaugemaster one. I'd linked the wrong one in my first post, I'd meant to link the 15v version. However that's nearly the same price as the known gaugemaster one, so not quite the saving I initially thought. 

[BlackRat]

So if the gaugemaster is 1.26A. 1.0A circuit breakers are the way to go?

 

http://www.maplin.co.uk/p/10a-auto-reset-circuit-breaker-ak07h

If you don't know any better, then a most definite yes!

 

The boxed one is excellent and more or less, ready to go and more importantly for you.......SAFE!

[CourthsVeil]

@Suzie:
When I said “in this case you are wrong” I was wrong   period

 

I had a rethink and tried my Gaugemaster HH with UNsmoothed DC as it comes out of my transformer with bridge rectifier attached (i.e. @ 50Hz ! ). Sure, it works, says my little cheap oszilloscope.
Just some 0.8V less than with plain AC (same transformer), but it works.

 

What does not work, is if we feed the HH with flat DC, i.e. out of a battery. Result in this case: 0.0 V…

 

I remember seeing a circuit supposedly showing the innards of the HH (don’t ask where in the depths of the Inet). Didn’t understand it, but it had two thyristors… No wonder it wants "wavy current".

Btw: typical of thyristors, this controller produces sharp spikes (rising flank) – which is why Gaugemaster do advise against its use with coreless motors.

 

I’m sorry

  Armin