Where to buy transformer for making DIY INVERTER

Hi all,

I am new to this forum and want help from you guys. I was following the post of making 50 W inverter at home. It is listed here http://goo.gl/tQa1V . I wanted to make it and then if successful, go for 500 W.

I then went to hall road to get the transformer mentioned in it (4A 12-0-12 V) but I was unable to find a transformer with this rating. Almost all people there had maximum 2.5A transformer.

Can anyone help me out where can I get 4A and even higher rating transformer in Lahore? What if I use 2A transformer?

Any other help related to transformer in inverter is highly appreciated.

Thanks Guys.


its output is squarewave .. where will be u uing it ?

i doubt it will be either efficient. also i m sure if u run normal ac devices on it u can destroy them ..

now regarding transformer. u may ask ups walas..

if its not available at hall road .. it difficult to get it then..

the site which makes didnt mentoned its specs.. how much current can it supply ?

if its 50 watt and output is 230 volts .. i think current will be little..

[quote=“nasirjavaid, post:, topic:”]

I then went to hall road to get the transformer mentioned in it (4A 12-0-12 V) but I was unable to find a transformer with this rating. Almost all people there had maximum 2.5A transformer.


For this inverter, a 12+12V 2.5A will also work but since it has extra winding 0.7+0.7 V bias windings, so it is hard to find such a transformer.

This 0.7+0.7 V winding is necessary because it makes this inverter self oscillating type. A simple 12+12 V transformer will not work here.

You need to get it made from some transformer maker on hall road.

Thank you all for your replies.

@Jhagra: Yes it is square wave and I plan to use it for just light and fan. I plan to add some modified/near sine wave circuit if possible. The transformer specs mentioned at site are 4Amps 50W 230V and you are right as it looks like I have to ask some UPS walas....

@Ijaz: You are right brother about 0.7V extra winding. This winding can be done on the transformer by wounding some extra copper wire. As you said 2.5A transformer so I think first I will have to try with this then I will go for the big transformer by asking some transformer maker at hall road.

My main intention is to run one fan on it and i think 100 W will be enough for this, so after success of first test project i plan to get big transformer. Can you please tell me the specs of transformer for 100 W output @230 V.

Also I am little confused with the relation of Amper & watts of a transformer. Searched google but did not find any satisfying answer

You can get transfer for 1500/= to 1600/= from Karachi's Local market that can handle almost 2 fans and 2 tubelights. (called 2+2) transformer in market.

Read this it may help you.


Thanks and best regards

Faraz Ahmed.

wow... got an answer after a long time... bye the way thanks imfaraz. I visited your link and found almost all the answers. Good skills you have there. Your UPS looks great and I hope you will provide some youtube video of how you made it. Due to no proper response here, I have asked a desi UPS maker for a 700W UPS last week and it will cost me 8000 for UPS and 11000 Phoenix 175/185 AH battery. But definitely I will love to try your provided information to make another one as I need to run PC and TV on ups in winter and desi UPS do not run PC.

Thanks for great sharing Faraz....

Well if you want to make UPS by urself here are few points.

1. Circuit (for Square wave with relay 400 to 450/=)

2. Body 400/=

3. Transformer = 1500 to 1800 (varies due to copper / iron prices)

4. Transistor or FET (For desi type UPS use transistors estimated cost including Heatsink Wire and transistors will be around 500)

5. Other stuff (sockets, AC Lead, DC Cables, Wiring cable, LEDs various other stuff) = 500/=

So it will cost you around 3800 to 4000/= to build a 2+2 (nearly 300W UPS) by yourself.

Now upgrade transformer and it will cost you 4500 to 5000/= built a 4+4 UPS (nearly 800W).

If you have questions contact me on my website ;)

Best Regards

Faraz Ahmed.

Thanks buddy. That is a great detail you have provided. I will be coming to you website for more related questions :)

............ and remember that such a ghetto home brewed setup is no where near any chaina mall that is produced on mass scale.. at least they have done some homework..

so y not buy one chinese in such a cost.. or add few thousands and buy a bit more powerful one. and this square wave thingy gona cause a lot of damage.

oh, but the ups guy said that I can run TV and chargers on this UPS and there will be no damage? Normally I plan to run only fans and savers on it :)

Nasir you have the patience to work in this much heat without any susti.Salute to you.

@Koder: Now a days I am using room air cooler :). which is sufficient to keep the room cool and when light goes, ups keeps circling my fan for 1-2 hours and i dont have to wakeup. planning to run my AC from next month when rainy season starts and humidity will be on peak. I hope you are clear now :D

How much effective is room air cooler? is it that big one which uses water or small?price etc-

Very effective. Actually in normal dry hot days we use something to cover ourselves as it throws so cool air. I have Super Asia RAC-450 P which is the biggest in its range. It is almost Rs:12000 now a days. I use AC only when there is too much humidity and cooler makes air even more humid :)

in Karachi we cant use room coolers :( as humidity matters

In karachi there is not so much heat either......as compared to punjab hot season :(