Help with a transformer

1/9/2011 4:28:07 PMJ-F

Hi,

I think I have a power transformer and I would like to know the voltage of the wires by color.

I made pairs of wires:

green + green = 0.3 ohm
red + green/white(?) = 8.3 ohms
brown + black/brown = 0.3 ohm

,- 1.4 ohm ------ black/white(?) ----,
|---------------- black | 0.4 ohm
'- 1.4 ohm ------ black/beige(?) ----'

where green, red and green/white are solid and other wires and stranded.

Look to be weird. I am lost.
Please help! :)

J-F

1/10/2011 2:49:20 PMEdd

Sir JF . . . . .

You might try this for a psuedo dynamic testing.

Figuring . . . that the:

Green---Green is a filament winding

Brown---Black/Brown is another filament winding

Red---Green/White is a single HV winding

That leaves the Black /Beige and the Black /White as being the primary, and uncertain,
if the Black is tied in to that winding , by the figures that you gave.

Considering the above info to be right, use the current limiting capabilities of a 60-100 watt
incand lamp in being in series with one leg of your 120VAC line input and see if the lamp takes
an initial slight lighting on plug in and then a settling down to a degree of glowing.

If no brilliant lamp lighting on power up you then might be correct on the primary winding input assignment.

Sample the AC output voltages from the windings . . . then go for the full 100 watt lamp in the series arrangement, to see if all is still OK and then see what the new output voltages are.

The actual output voltages should require a 10-20 percent loading down of a winding to bring it down to the expected output voltage design spec of the transformer.

The OTHER possibility . . . if this is not a RADIO type of transformer . . . that it might be a control type of transformer with that Red---Green/White winding being the primary, and the Green---Green and the
Brown---Black/Brown being the lowest voltages and the Black /Beige and the Black /White being an intermediate AC voltage . . .like 24VAc or so and the Black being its centertap.

Currently not knowing if this is a tube radio related transformer . . . . I probably would initially assign that Red---Green/White winding as being the primary in my initial testing . . . and lean upon this unit being a control type of transformer.

The voltages read for the Green---Green and Brown---Black/Brown windings will tell you a lot, either way that you test it out.

Thassit . . . . .

73's de Edd

:Hi,
:
:I think I have a power transformer and I would like to know the voltage of the wires by color.
:
:I made pairs of wires:
:
:green + green = 0.3 ohm
:red + green/white(?) = 8.3 ohms
:brown + black/brown = 0.3 ohm
:
: ,- 1.4 ohm ------ black/white(?) ----,
: |---------------- black | 0.4 ohm
: '- 1.4 ohm ------ black/beige(?) ----'
:
:where green, red and green/white are solid and other wires and stranded.
:
:Look to be weird. I am lost.
:Please help! :)
:
:J-F
:

1/11/2011 7:23:52 AMJ-F

Yes, black is the center tap.

Can I assume that the primary winding is the one with the higher impedance?

Because the transformers I was able to identify (2 of them), have a primary between 4 and 15 ohms, while all the secondary from 0 to 2 ohms. I am sure that they are power transformer for tubes.

For others, I'm really not sure. Is there a color code for the wires?

1/11/2011 5:27:25 PMEdd

Sir . . . . . JF
Do the evaluative testing as I described, initially using the highest Z winding as the AC primary and see if the AC output from the windings resemble any common voltages.
The RETMA common color coding for transformers are as shown below.

BUT in some RCA solid state power transformers of the 60-70's I have seen green /red, green /black and black used for the primary windings markings .

Le coleur codes du transformateurs:

73's de Edd

:Yes, black is the center tap.
:
:Can I assume that the primary winding is the one with the higher impedance?
:
:Because the transformers I was able to identify (2 of them), have a primary between 4 and 15 ohms, while all the secondary from 0 to 2 ohms. I am sure that they are power transformer for tubes.
:
:For others, I'm really not sure. Is there a color code for the wires?
:
:
:
:

1/11/2011 5:42:18 PMJ-F

Merci pour le code de couleur! :)

Thanks a lot for the infos!