9-0-9 500mA - my transformer heats up tremendously

[shreekalak]

my transformer is heating

i am using a 9-0-9 500mA transformer which drives my pic 16f73 and a LCD 16*2 attached to it.
when i switch on the power within 5 min my transformer heats up tremendously..
i am not able to understand the problem..
please help me soon..
its urgent..
i m stuck at this point..

 

[Awarapunshee]

cause of transformer heating

There are many possibilities.

Check the transformer can supply the current required, for this, just disconnect the 9-0-9 terminals of the transformer from the circuit and give it 220VAC (or 110VAC what ever your input supply is) and check after 5 minutes, if it heats up, then the problem is obvious, i.e Transformer. post the result for next action.

 

[shreekalak]

transformer heating

i checked it but at this time transformer doesnt heat...
i have given this supply to 7805 and then to pic micro controller..
please tell me the problem..
help me urgently...

 

[shrikant_varpe]

why my transformer is heating

current require for backlight is more try LCD display without Backlight, otherwise u need more current rating transformer.

 

[Awarapunshee]

Re: transformer heating

i checked it but at this time transformer doesnt heat...
i have given this supply to 7805 and then to pic micro controller..
please tell me the problem..
help me urgently...

measure the voltage across the transformer while connected with the circuit, if it is below then the current requirement of your circuit is high. Use the higher rating transformer. What about the 7805, is it also get hot?. and secondly is the power of LCD through this regulator? Does LCD has any heater plate etc.

 

[shreekalak]

Re: transformer heating

my 7805 is connected to the transformer doesnt heat up...
but there is one thing which i have used is i m using two different transformers of different ratings which gets supply from same mains point...
can that be a problem???????

 

[FvM]

Re: transformer heating

i have used is i m using two different transformers of different ratings which gets supply from same mains point... can that be a problem???????

Yes, if in- and outputs are connected in parallel. Your circuit gets more unclear, actually. Why don't you show the exact circuit?

 

[Awarapunshee]

Re: transformer heating

my 7805 is connected to the transformer doesnt heat up...
but there is one thing which i have used is i m using two different transformers of different ratings which gets supply from same mains point...
can that be a problem???????

If you told it before than it will be obvious. And even you neither upload your circuit and nor give us the exact picture in writing.

 

[pranam77]

transformer heating

Hai shreekalak
Hope you are from India. Here we find many sub standard transformors where they mention as 500Ma but actually as per winding wire guage, it will be only 300-350 Ma. This is a main cause of heating nothing else. First connect the circuit to a regulated lab power supply with 5 volts output. then measure current required. Use a transformer with 4 times the required capacity. Eg: If you get 200 ma with Lab supply, use 1Amp transformor. Or get a good transformor like "Denen, Coil n core" etc which will naturally cost double of the normal transformor you have at present. These will have the rating specified but will come at a price. Good luck