Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Transformer Problem explanation needed

Status
Not open for further replies.

wf1318

Newbie level 4
Joined
Oct 31, 2007
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,334
Transformer Problem

Hello, I have some question about transformer.
I have a transformer that is 220VAC input, 12VAC output, 12VA...

My questions are:
1. What is 12VA meaning?
2. How can I know the max. current of this transformer?
3. If I swap the input & output.......therefore it will become 12VAC input, 220VAC output......so, what is the max. current of this transformer now???


Thanks!
 

banjo

Advanced Member level 2
Joined
Dec 24, 2005
Messages
651
Helped
127
Reputation
254
Reaction score
8
Trophy points
1,298
Activity points
8,070
Transformer Problem

VA stands for Volt-Amp. It is the product of the AC voltage and current. Therefore, you transformer is capable of 12V at 1A output.

If you reverse the transformer, you step up the voltage, but step down the current. Therefore, I would expect about 55mA output at 220VAC.

P.S. The VA rating of some transformers is very generous. When run continuously at that load some transformers will run hot and the output voltage may sag.
 

P

pauloynski

Guest
Re: Transformer Problem

Furthermore, the VA rating is commonly specified at "the maximum current that heats the transformer to a certain temperature, usually 70°C, with resect to an ambient temperature of 25°C using a resistive load".
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top