I have a bose 3-2-1 system bought from USA by a friend with 120VAC, not knowing its not suitable for my country using 220-240VAC. I have decided to change the mains transformer rather than to use a step-down transformer. It's oringinal transformer has only the primary and secondary winding, and there is no specs rating printed on it. I wish to know what is the secondary winding AC voltage & Amperes of the transformer.

James Goh, March 2010

Take 2 light bulbs and wire them in SERIES - each will have 120V across it. Temporarily connect the USA transformer (off load) across one ot the light bulbs. Measure the secondary - my guess is 15V.

The amps will be the wattage rating of the device (the player should have a rating plate) divided by the voltage. i.e if an 30W machine then the primnary will be 30 divided by 240 = 0.125A and the secondary (if the winding really does provide 15V) 30W divided by 15V = 2A

Frankly I don't see it mattering too much - a transformer of about the same size will work - and it's very likely that any secondary from 12 to 24V should be OK - there will be circuitry to sort out the required DC voltages that should be able to cope with a wide variation of input volts.

Good luck...

Peccavi, March 2010