# help w/transformer id/markings ?

Discussion in 'Electronic Repair' started by robb, Nov 4, 2007.

1. ### robbGuest

i have a transformer that i am trying to understand what it
suppose to produce from the different wwires

the transformer only has these markings
92-326-416-91 115v 60hz
30/8/2 x 2.3v
VDE0551 UL

i have googled these numbers to no end

do these numbers give some clue as to nature of transformer ?
or enough info to find a suitable replacement ?

or enough to test it andhow would one test a transformer kjust
check volts at various pins

any help or links describing the meaning of numbers would be
greatly appreciated

thanks,
robb

2. ### JamieGuest

lets see.
115volts input at 60 hz.

30 volt out tape, 8 volt out tap, and 2 2.3 volt taps.
hows that for guessing ?

3. ### robbGuest

Thanks Jamie.
but that I can find those values on various combinations of
taps/pins (along with other values) but they are not what i would
expect ?

that is the transformer has the 2 - 115v input pins and then 8
output connectors,
the 8 outputs *by continuity tests are grouped 3/3/2 and the
voltages are not a predictable pattern

i get something like this where (#) is an output connection and
___ covers continuity group

_________________ __________________ __________
(1) 2.73v (2) 2.73v (3) (4) 8.22v (5) 16.42v (6) (7)
28.8v (8)
\ / \
/
` 5.45v ' ` 8.22v
'

does this make sense >

thanks for help
robb

4. ### JamieGuest

I think what you have is a CT (center tapped) 1,2,3. 2 being the tap for
common to drive a full wave 2 diode rectifier or, used 1 and 3 to drive
a full wave bridge for 5 volts. The next set is also a CT with 8 volts
from CT to CT or, 16 volts if you don't use the CT. and the last one
is just a 28 volt out or 30 as indicated on the xformer with no CT>

Not sure what type of logic this is driving how ever, I would guess
that it maybe supplying a 3.3 V regulator from the 1,2,3 points and
a maybe a five volt regulator from 3,4 and 5 points.

You can also config it so that when using a bridge rectifier, you can
get a + and - supply with respect to common via the CT>

5. ### robbGuest

thanks Jamie,
this transformer connects to two bridge rectifiers. 28 v goes to
rectifier to power a VFD
and the 8 or 16 v to a rectifier to power a dual full bridge
driver *L298* and then the 5v for ICs ?

i guess i was expecting more predictable voltages like 5/12 etc.
but was getting 5.27, 8.32 etc...
so iwas not sure if maybe there was a problem with the
transformer.

thanks for the help,
robb