Another AC power transformer that I have found in my "Aladdin's cave" from a long ways back in time, it definitely was extracted from some Japanese audio gear but I did not record which item it was. My thought is (but I cannot be sure) that the gear was a solid state amplifier with that 6V supply being used for the incandescent panel lamps.
AC POWER TRANSFORMER
Country of origin is probably Japan (but not stated on the transformer)
Please be aware that there is no mention of International or Australian safety standards indicated on the labelling
ID printing on the transformer is:
5T-697 (secondary side)
2720 (each side of the frame)
No other markings other than the voltages at each terminal
Type: E iron core
Primary & Secondary are fully isolated - this is NOT an auto-transformer
All terminals are solder tag
Primary winding has terminations for 240V, 100V (100V is used by Japanese power systems)
The secondary has terminations for 33-0-33V and an additional winding for 6V - these two windings are totally isolated and not just taps.
These are all marked on the transformer insulation card/paper material ... please read my test results below to see what I actually measured, the secondaries read slightly lower voltages than indicated.
DIMENSIONS:
Body: 60mm wide x 73mm height x 64mm depth
Mounting tabs are L shaped and extend the total width of the transformer to 80mm
WEIGHT:
960g
TESTING:
I made basic resistance tests on all windings but tested the secondary outputs using ONLY the 240V input winding, not the 100V winding.
Secondary outputs measured
28.3V AC
28.3V AC
6.5V AC
Note that the printed indication of the higher secondary voltage is 33V, so this transformer is reading around 10% lower than that and this is under no load conditions. Keep this in mind, it means that under load you MAY only have around 50V AC available from the 33-0-33 winding.
The low voltage 6V winding is fine
I also checked the insulation resistance between both the primary and secondary windings to the transformer frame - here I am reading infinity using a 500V megger.
COSMETIC CONDITION:
USED
Clean
NO signs of previous stress at all
ALL solder terminations are secure and undamaged
NO damage to the windings insulation
This transformer is now safely packed into a sealed clear plastic packet, waiting to do some work once again
