Ex Soundcraft (NZ) audio equipment
Transformer is very well made and includes the copper band, the purpose of which is to act as a shorted turn, which reduces inductive effects in the circuit from the leakage inductance formed by the leakage flux. The copper band also works as an electrostatic shield, reducing EMI.
There is also a single green wire (originally taken to earth) which is NOT connected to this copper band or the transformer frame - this must be connected to an internal shield (Faraday shield) and when this is connected to ground, it shunts some noise and transients to the ground path rather than passing them through to the secondaries of the transformer.
This transformer is designed to be as "electrically quiet" as possible, especially suitable for sensitive audio circuits.
AC Power Stepdown Transformer
New Zealand manufacture but it is NOT marked on the transformer
Iron E core
Dimensions: 73mm wide x 83mm deep x 90mm high
Weight: 2.1kg
AC input: 230 or 240V (Labelled on the core)
AC outputs:
16-0-16 - great for op amp circuits requiring a dual low voltage supply
16 - general purpose low voltage output
32 - general purpose medium voltage output (used in the equipment to power an audio amplifier module)
I do not have information about the current capability of each output but based on the equipment being powered and the size of this transformer, the 16V and 32V windings will easily provide up to 2A each and the 32V centre-tapped around 500mA (it was only powering some low current logic & signal processing boards)
It would be pretty safe to assume a total dissipation of around 100W as a conservative estimate.
All secondary windings are electrically isolated from each other i.e the 16V, 32V and 32V centre-tapped windings are all separate windings.
COSMETIC CONDITION:
Excellent condition
Laminations very tight
Very well constructed transformer
Supplied with the 4x mounting bolts
TESTING:
Thoroughly tested whilst still installed in the equipment (multiple cassette machine for auto-changing music system - model MM106)
Voltages measured were under load, very little change when no load was present either.
No audible lamination noise - laminations and windings are tight
Checked the green wire connected internally (Faraday shield) and it has no direct connection to any winding, the copper band or the transformer frame.
The secondaries voltages were not marked on the transformer so I have written them onto the copper band to help with identification.
Since removal from the equipment, this transformer assembly is now stored within sealed plastic.
