I am trying to make a very compact converter from 220v to 110v without a stepdown transformer to be able to run US small applications like adapters in Indian voltage standards. Are there any tutorials to do such kind of a conversion? I am a novice. Any help would be appreciated.

 

Originally posted by monsterous@May 7 2006, 10:39 AM
I am trying to make a very compact converter from 220v to 110v without a stepdown transformer to be able to run US small applications like adapters in Indian voltage standards. Are there any tutorials to do such kind of a conversion? I am a novice. Any help would be appreciated.

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I think it is a dangerous idea. Any appliance that draws appreciable power is going to make a non-transformer based conversion scheme get quite hot.

 

Originally posted by Papabravo@May 7 2006, 07:46 PM
I think it is a dangerous idea. Any appliance that draws appreciable power is going to make a non-transformer based conversion scheme get quite hot.

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A SMPS might help, but it is quite complex to design, esp. AC to AC.

What amount of power are we talking about?
For exmple notebook suplies should be capable of runnig off 220V, and will also happily run from 120V DC.

 

Originally posted by kubeek@May 8 2006, 01:23 AM
A SMPS might help, but it is quite complex to design, esp. AC to AC.

What amount of power are we talking about?
For exmple notebook suplies should be capable of runnig off 220V, and will also happily run from 120V DC.

[post=16885]Quoted post[/post]​

I need 9v 1A and 7v 350mA. I think that is not a lot of power. The problem I am facing is that if I make a new adapter for every application, I have to collect all kinds of spare parts, which is sometimes impossible.

 

Originally posted by monsterous@May 8 2006, 06:30 AM
I need 9v 1A and 7v 350mA. I think that is not a lot of power. The problem I am facing is that if I make a new adapter for every application, I have to collect all kinds of spare parts, which is sometimes impossible.

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First you ask about AC/AC conversion, then you give us what sound like DC specifications. Nine watts (9V * 1 A = 9 W) doesn't sound like a great deal of power until you try to get that much heat out of a small package. So I'm confused. What do you actually want?

 

Originally posted by Papabravo@May 8 2006, 07:56 PM
First you ask about AC/AC conversion, then you give us what sound like DC specifications. Nine watts (9V * 1 A = 9 W) doesn't sound like a great deal of power until you try to get that much heat out of a small package. So I'm confused. What do you actually want?

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After I convert 220V to 110V, I will be able to use the adapters with 110V input which came bundled with different devices.

 

Why is a step-down transformer to be avoided? A 9va transformer would not be very large or very expensive.

 

Depends what your powering. Transformers are the best answer. Years ago there used to be small step down converters about that used to chop up 230v AC with a Triac, similar to a light dimmer.... usefull for heating or lighting (resistive type loads) but they used to totally fry any 110v electronic appliance or transformer front end pluged into them. Used to get a lot of customers buying them in the USA along with a stereo or something, bring em back over here...plug the whole kit and kaboodle in and WHAMMO, the blackened mess arrived on my bench soon after.