On 2019-10-01 19:07, Bo-Lennart wrote:
Den fredag 27 september 2019 kl. 19:48:15 UTC+2 skrev Bo-Lennart:
Hi all out there.
I found a transformer in my basement. I don't know if its a audio-output transformer or just a power transformer.
On top it's stamped "GALVIN MANUFACTURING CORPORATION",
and a model #: "25B31296-E" and a serial# ( ???? ) "138226"
At bottom there is 8 solder lugs, stamped: "1 to 8".
And at one side is 8 screw connector, labeled as "3A 12 11 2B 2A 10 1A 9".
To me it looks more like a tube output transformator, more than a power transformer.
It seems to be from the 1940 or somewhere around there.
Anyone know what it is, and have some kind of "schematic" of the transformer.
Many thanks in advance
Bo-Lennart Karlsson
Falun, SWEDEN
I have uploaded som picture of the trafo. And I made a schematic of the
transformer.
Here is the links:
https://i.ibb.co/Jx3RtLR/20190929-155553.jpg
https://i.ibb.co/mh0k6rB/20190929-155912.jpg
https://i.ibb.co/z4PV2JZ/20191001-164147-001.jpg
https://i.ibb.co/QYVPqwR/20191001-164228.jpg
https://i.ibb.co/NKDynrF/20191001-164522.jpg
https://i.ibb.co/0Qq2xf0/20191001-164553.jpg
https://i.ibb.co/c2Rtcqw/20191001-164606.jpg
Well, I'm an old man (turned 70 early this yr), and I started my electronic profession very young. At that time the car radio had VIBRATOR to make 12V (or 6V) transformable.
And I start to think that it's a such transformer.
The screw-terminal could be switchable between 12 and 6 Volts use ?????.
How about that? Anyone have a better suggestions?
Best regards
Bo-Lennart Karlsson
Falun, SWEDEN
Hi,
Never knew Motorola started as Galvin Mfg Corp:
https://en.wikipedia.org/wiki/Motorola.
That tranny could be a real museum piece!
Could you double check the inductance between 7-8?
The combination of much higher inductance and still a low DC resistance
looks suspicious. Was it not 3.08 mH? Then it could be the separate
filament output for an HV rectifier tube.
The HV output for a vibrator transformer would have high resistance
(like 4-5-6) but a much higher inductance than the input windings, and
it isn't. Also suspicious.
Some 50 years ago I've repaired an old 12V (or 6V?) input tube
car-radio, and it had a vibrator inverter. However, the transformer was
much less complicated: just two primary and two secondary windings.
There was no rectifier tube, the vibrator also rectified the HV. The
tube filaments were directly run on the incoming 12Vdc.
Arie