230V to 12V 1A Transformer - Where to buy?

[crosstalk]

Can someone give me some pointer where to buy a good 230V to 12V 1A step down transformer?

230 Primary.
0-12 Secondary.
1 Amp.

I am from Kolkata and good quality transformers seems to have vanished from the marketplace here.

Either they are not of 1A and sold as 1A and then, they generate hum that can be heard normally (without any speaker connections).

A normal EL Type transformer will do.

 

[Fantastic]

Just do a Google search for EI transformer manufacturers in Kolkata or India. Of the many you will find, there is Delta from Delhi, Miracle from Bangalore and so many others who will wind what ever you want and ship it to you.
I'd say you should stick to suppliers in Kolkata. I'm sure there are many good manufacturers there.

Humming transformers without any connections are due to poorly installed cores or lose windings. Both cause increased loss in the transformer.
This generally shouldn't happen nowadays. It doesn't if you buy from a good manufacturer.

 

[saheb11123]

Gemini radio and NG they seem to produce okay-ish quality EL traffo. I have one if you'd like then can take it.

 

[IndianEars]

If you plan to use this to generate 12Volts DC @ 1 ampere, and the application is not too demanding by audiophile standards, do consider readily available 12VDC SMPS (Wall Wart) power supplies. They are built into the moulded plug and are made for replacements for Cable TV and DTH Set Top Boxes.

They are available in Mumbai's Lamington Road for Rs 150 to Rs 225.

Yes, they ACTUALLY deliver 1 Amp @ 12 Volts

 

[crosstalk]

Indian Ears,

Thanks for the tip. How about using a laptop adapter and regulating it via 7812?

 

[crosstalk]

Gemini radio and NG they seem to produce okay-ish quality EL traffo. I have one if you'd like then can take it.

Saheb,

What is the make? PM me a price if you would.

 

[saheb11123]

The brand they sell at chadni (the place I suggested) is golden. They would cost you around Rs 200 for 2 amps.

The one I have you can take it if you like , you don't have to pay me anything for that.
:-D

 

[tiger0691]

Go to any shop for electricity.
You can get it in your local market.

 

[turgid]

Hi,

You can get them made from a seller in E-bay.in.

They will ship it to your door

I got 240to3V, at 350mA ...let me know if you can't find it. I will post their number.

Best regards,
A~

 

[Fantastic]

Indian Ears,

Thanks for the tip. How about using a laptop adapter and regulating it via 7812?

The laptop adapters I have used so far are all 19 V. Yes you can use a LM7812 to drop it down to 12 V. You might need a heatsink to dissipate the heat lost on the regulator. 7VxI load ( in amps) in watts is the heat loss. The electronics market has a huge range of heat sinks off the shelf.
Look up selecting a heat sink on Google and it might tell you what size to pick. If you have an idea of what shape you are looking at , it will be easier to select the size. For low currents you could get away with a plain piece of sheet aluminum , usually 1.6 to 2 mm thick. But you NEED to know how much it has to dissipate.

What is your load current ?

 

[IndianEars]

crosstalk said:

Thanks for the tip. How about using a laptop adapter and regulating it via 7812?

Sorry I was travelling and could not respond.

Yes, using a Laptop PSU with a series regulator would be Great.

An LM317 with a few more components would even out perform the 7812 for audio duty.

I totally agree with Fantastic's advice.

 

[G Annaji]

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