Power Supply

Evolution1

I'm trying to source a transformer .
Needs to be 220v - 9V AC /AC at at least 3.34amps .

No problem if I have to do a bit of soldering .

2011

Try Maplins:

http://www.maplin.co.uk/store-locator/republic-of-ireland-region

Evolution1

I've tried radionics . CPC,
Will look at maplins

Evolution1

not much luck .

Bruthal

Evolution1 wrote: »

not much luck .

Whats the application

Evolution1

It's an alarm . Coming from the USA.
The american transformer is 110v - 9VAC @ 3.34 amps 36watts.
The panel needs this with all the gizmos attached . GSM modules use a lot of mA.
But I won't be using one . . Just the panel alone .

I have a 9VAC 1250mA transformer of the older version of the European model

Someone on boards before ordered one and lads from electrical gave him a list of components needed . But he never went through with it and stuck to his power converter which has caused him trouble .

Kristopherus

Try Amazon.co.uk.

Bruthal

Here you go. Select 9v 40va one from list. It is the first 40va in list.

Steve

http://www.merrimack.ie/

They'll build you a custom traffo but be prepared to pay a one-off price.

Evolution1

Steve wrote: »

http://www.merrimack.ie/

They'll build you a custom traffo but be prepared to pay a one-off price.

Is that the gate automation place?

Evolution1

Evolution1 wrote: »

Is that the gate automation place?

Ah yeah I know the place .
If it means getting a proper enclosure then it's worth it .
Would it cost more than €50 quid ?

Steve

Evolution1 wrote: »

Is that the gate automation place?

Yes.

Steve

Evolution1 wrote: »

Ah yeah I know the place .
If it means getting a proper enclosure then it's worth it .
Would it cost more than €50 quid ?

If it's something they stock then it's usually priced well, one-offs can be expensive though.

Evolution1

Ok thanks lads il give them a call on Tuesday

adrian92

Perhaps it may be an option to get a 220v/110v 40Watt trafo - and then link up to the US system. Perhaps something like shaver outlet would do it?

solas111

Steve wrote: »

http://www.merrimack.ie/

They'll build you a custom traffo but be prepared to pay a one-off price.

I would also recommend Merrimack Transformers. Dealt with them a few times at work and they were very helpful.

Evolution1

Il try Merrimack .
If the price is too high il order the parts and assemble .
I don't want to use any power converters.

adrian92

Evolution,

I just wonder of needless complication.

Seems just a tiny power source 220v/110v c. 50VA required.


Could buy this in a pound shop nearly

Evolution1

I'm new to transformers and any 9v 40va encapsulated transformers I've looked at dont have it clearly labeled whether its output is 9v AC .
Could someone explain the 40Va or 50Va part

solas111

The VA gives you the power output of the transformer in Volts x Amps but with a.c. there is also the power factor involved. However, since you know that you need an output of at least 3.34 Amps, you need not worry about VA. Just get something that is a bit above 3.34 A. Going too high in amps output is no harm so leave a bit of spare but don’t go too low or you may have overheating problems and eventual failure.

Most of the 9 volt stuff that you can buy off the shelf will be in milliamps and will not have a high enough output so it may not be that easy to get a ready-made transformer.

Evolution1

So Va would only be used on transformers with an AC input and AC output .
Going to wait a few days before it arrives to order the parts .
I'm guessing its just a matter of soldering the live and neutral to the input side and then soldering to the output AC terminals. .

What are the chances that the transformer will destroy the unit .

solas111

All transformers have an a.c. input and output as transformers can only work on a.c. If a d.c. output is required, something else has to be connected to the output side in order to convert the a.c. to d.c. but the transformer will be rated in VA regardless of the type of output.

You need to be careful here as there may be several terminals on either the primary 220 volt side or more likely on the secondary side. You could easily end up with the wrong output voltage and destroy your equipment. My advice to you is to get someone who knows how to do it and who has the knowledge and equipment to measure the output voltage.

Bruthal

Evolution1 wrote: »

So Va would only be used on transformers with an AC input and AC output .
Going to wait a few days before it arrives to order the parts .
I'm guessing its just a matter of soldering the live and neutral to the input side and then soldering to the output AC terminals. .

What are the chances that the transformer will destroy the unit .

VA is simply volts x amps, and is used because loads can vary in power factor, so a kw rating is not accurate for the output rating of transformers, generators etc. VA or KVA for larger transformers/generators tells us the amount of amps the device can supply. What KW this amps level can power depends on the load power factor. So the transformer can`t really be rated in KWs.

Even if you used a 10,000 VA transformer to power your device, it would work fine, once the voltage is correct from the transformer. Too small a VA wouldnt work properly though.

A multimeter should be used on the output terminals of the transformer to check actual voltage. Once its close to 9v it should be ok.

It would probably be more true that a transformer with DC output could be rated in watts alright since power factor doesnt really come into it in DC loads, but they are still rated in milliamps or amps output.

Evolution1

Won't learn anything if I get someone else to do it . I have a multimeter and access to loads of other equip .

CpC Sent me an email in regards to this transformer

http://cpc.farnell.com/camdenboss/ctfc50-9/transformer-50va-2x-9v/dp/TF01349?Ntt=TF01349

but it says 2 x 9v.
Does this mean I can connect two 9v loads .


http://radionics.rs-online.com/mobile/p/chassis-mounting-transformers/0504656/

Should the above transformer work ?

Bruthal

Evolution1 wrote: »

Won't learn anything if I get someone else to do it . I have a multimeter and access to loads of other equip .

CpC Sent me an email in regards to this transformer

http://cpc.farnell.com/camdenboss/ctfc50-9/transformer-50va-2x-9v/dp/TF01349?Ntt=TF01349

but it says 2 x 9v.
Does this mean I can connect two 9v loads .


http://radionics.rs-online.com/mobile/p/chassis-mounting-transformers/0504656/

Should the above transformer work ?

The cpc one would need you to connect the 2 primary windings in series for use with 230v, and the 2 secondary 9v windings in parallel for the 50va 9v output. The secondary could also be connected with both in series for 18v 50va.

The connections would have to be done right, but the transformer would likely come with the connection diagrams for all setups.

The radionics one also looks like it has 2 secondary windings too, so also connect them in parallel for 9v 50va capacity. They have to be connected in parallel properly, as it can be done wrong. Likely the transformer will come with connection diagrams anyway.

Evolution1

I ordered from radionics €25 quid .
Should be here tomorrow or Wednesday .