HISTORY:
This E iron core AC step-down transformer was extracted from a Weconic power amplifier, designed in Germany but manufactured in Taiwan. This means that the transformer is most likely Taiwanese made to German specifications. The label on the transformer (PRO1) refers to the equipment, not the transformer part number and in fact there is no transformer manufacturer indicated or safety standards mentioned.
It looks impressive but I would only use this "conservatively", meaning that it may not be wise to exceed total power output beyond around 250VA as I do not know how this transformer may perform "under pressure"
Please read on if interested, full physical and some technical details are below ...
UNIDENTIFIED MANUFACTURER - AC Power Transformer
Most likely made in Taiwan
Wound for Australian conditions i.e 240V/50Hz primary, not 220 or 230V
Nice Copper flux band
Physical: E core laminated
Type #: PRO1
Primary AC Voltage: 240V
Secondary Voltage 1: 35-0-35V @ 3.9A
Secondary Voltage 2: 15-0-15V @ 500mA
ALL windings are completely isolated, this is NOT an auto-transformer design.
Printed on the transformer label are the winding voltages and a schematic and the wires correspond with the label i.e where 0V is indicated, the wire next to that text is indeed the OV (centre tap) point.
Secondary windings terminate with two 3 pin female plugs, just cut these away if direct wiring.
Primary winding is flying leads
Frame has a standard 4x mounting slot arrangement, no mounting screws/bolts supplied - some heavy duty bolts would usually be used here.
DIMENSIONS:
120mm height x 98mm width x 93mm deep
Base mounting area is 100mm x 120mm with 6mm x 10.5mm slot holes in each corner for mounting
Secondary leads are all 140mm length
Primary wires are 140mm & 260mm length (one is shorter than the other)
WEIGHT: 5.2Kg
COSMETIC CONDITION:
USED
CLEAN
NO damage to the laminations or frame
NO damage to the side mounted winding exit strips (plastic)
Light topside discolouration is obvious, this is oxidisation and ONLY on the top - this is where air flowed from the working environment through the amplifier case vent slots.
TESTING:
This is what really matters, how does it perform?
Prior to equipment dismantling, this equipment was functioning just fine but then over time a couple of physical issues occurred which rendered the equipment inoperable (failed special power switch and a broken spline pot shaft)
Let's kick this transformer into life and make some voltage measurements ....
NO power on surge current which can create a clunk or buzz when first powering up a high current transformer, even without load.
I have not loaded up the secondaries so I could not check properly for lamination buzz but with no load it is very quiet (as it should be!)
Measured AC secondary voltages as 29.84V (14.92-0-14.92) & 69V (34.5-0-34.5) NO LOAD
I was a little surprised at these voltages, with no load I would expect a bit higher than this as these secondary voltages will sag slightly when under load so I feel the realistic expectation from the high current secondary (35-0-35) is more likely to be around 30-0-30 under full 4A load conditions.
It's a bit tough when there are no manufacturer specifications to check on ...
