DIYbanter - View Single Post - Repairing Grundig cd-player, transformer identification problem

Gary Tait

wrote in news:1177524925.077103.37250
@u32g2000prd.googlegroups.com:

Hello!

I have a over 10-year old Grundig model CDC477 (5 cd changer) with a
dead transformer and i need to replace it. The problem is that I don't
know the exact mA and V ratings for it. I tried to contact Grundig and
AMC about it but they haven't answered.

The transformer is made by AMC and it has the following markings:
1st line: AMC-logo and "95" "30"
2nd line: "99.2139302FM"
3rd line: "3104 113 70491"

The input voltage is 230V. The transformer has two outputs which each
have 3 wires. The first has white, green, white. The second has blue,
red, red.

These wires go to some sort of circuit with mainly electrolytic
capasitors (16V and 50V types) and diodes. From this circuit leaves 7
wires which are marked to be +10V, -10V, +3V9, GND, -27V, 4V8~ and
4V8~

Those 4V8 AC lines come straight through the circuit I described
above, so one of the transformer outputs is 4V8 AC. But what might be
the other output?

This really sounds like a puzzle, but thanks in advance ;-)

I am guessing the unit has a VFD, which the 4V8~ would be the filament,
the -27 the drive, and a very small current. Depending, the 3v9 could be
a logic frequency.

I would think there would be`separate supplies for the motors, logic,
and audio circuitry.

Outward guess, one winding is the centre tpped 4v8, the CT to ground.
The -27v derived from the other winding with a doubler, the CT making
10V or so, either way.

I think the 10V supplies might be 500ma each, the 3v9 maybe 1A, if it
does the main system logic.