A question about transformers

[Mike555]

I'm kinda confused about the mA and A markings in some transformers.
What do they actually mean? Do they mean that the transformer outputs, for example 500mA or that it can do up to that point?
Thanks in advance!

 

[GonzoEngineer]

It is usually the maximum current it is rated for, I believe...

 

[davenn]

yes, thats the maximum current the transformer can supply
Depending on what the load (of your circuit) is on the transformer, the load may draw part or all of that.

This is a common misunderstanding amongst new comers to electronics
the common question is ... will my 12V 300mA device blow up if I put it onto a 12V 10A rated power supply ?

Answer ... no it wont, the device will just draw the 300mA it requires from the PSU

Dave

 

[Electrobrains]

In general about transformers: They are usually very tough fellows!

The rated power (VA, not Watt), voltage and current of a transformer are referring to a max. continuous load on the secondary side at a specified temperature (often 40°C).

That load can without problems be exceeded by great factors for shorter time (seconds, minutes).

If Miguel Lopez reads this, maybe he also has a formula for overloading transformers...
Basically it has to do with the inner temperature of the transformer and that the isolating materials will not get damaged.

 

[Mike555]

Thanks to you all now i understand the differences
Have a nice day