Hi All,

I have a problem -- output voltage of 230V - 9V transformer is not 9V,
but around 14V!

A couple days ago I have bought a small 230V to 9V transformer, it
looks like this:
http://www.inetcat.org/stuff/transfo...ransformer.jpg.

The transformer is a part of a power supply module, it is followed by
7805 regulator. After I have assembled the circuit I have noticed that
7805 is running hotter than I expected. Soon I have found the problem
-- the output voltage of the transformed is much higher that 9V,
around 13V.

Today I went to the shop again and bought another one. Similar effect:

http://www.inetcat.org/stuff/transfo...mer-output.jpg.

A little black box on the top is the transformer. White wires go to a
wall socket, 230V AC. Two multimeters measure AC voltages, left -- on
the primary windings, right -- on the secondary one.

Why a voltage on the secondary winding is 14.4V? The multimeters are
ok, I can swap them and get the same readings. Am I lucky enough to get
two faulty transformers? It is theoretically possible, both are likely
to come from the same batch. I fail to see what else can be wrong...

I am thinking about go back to the shop and complain, but would like to
hear somebody else's opinion first. Would anyone please care to
comment? Am I missing something about AC transformers labeling?

Please help.

Kind regards,
Alex