Mains adaptor for portable CD player

[MalcolmY]

The operating manual for my recently purchased Sony CD player (Model D-EJ021) says I should use a mains adaptor with rating of 4.5 V / 700mA.
I have a couple of mains adaptors, one with rating 4.5 V / 800mA and the other with 4.5 V / 300mA. Can I use either (or both) of these or do I have to try to find a 700mA adaptor - which local Comet / Currys don't stock?
(Yes, I know I can run it with just the AA batteries but I'd like to use an adaptor!)

[squarebear]

I would advise you use the adapter it specifies or else you risk damaging your CD player.

[ABerrant]

The amperage marked on a power supply is the nominal maximum current the attached appliance is able to draw. (It's a bit more complex than that but not relevant to include the full explanation).

If the CD player requires 700mA it is able to draw that from a supply rated at 800mA but not from one rated at 300mA. The CD player decides the current draw, not the supply, but the supply cannot give more than its maximum.

[paintpowder1]

I agree:if you use any mains adaptor set at the required voltage,then using one with a current rating of 700mA or higher will be perfectly fine.

[Buenchico]

I'll agree with both ABerrant and PaintPowder1, with just one proviso. There should be a little diagram on your 800mA adapter showing whether the centre pin of the connector is positive or negative. There should be a similar diagram on your CD player. Please ensure that they're both the same.

Most modern electrical devices are fitted with a diode, in the power input circuit, which prevents damage if a 'wrong polarity' power supply is used. (If so, and you've got the wrong polarity on your adapter, the CD player won't work but no harm will be done). But there are still some manufacturers who omit such a diode; using the wrong polarity with such a device would be disastrous.

Chris

[beso]

In my experience most appliances are not fitted with a diode and wrong polatity will destroy them.

You must also be careful with using a transformer adaptor that is too powerful as they will have a higher no load voltage that may damage the appliance. However the 800mA adaptor is probably close enough.

There are also variations of the centre pin size in otherwise identical looking sockets.

[Davethedog]

Didn't it come with an adaptor?

[MalcolmY]

Dave-t-d
No, it doesn't come with an adaptor and the assistant in Comet said they don't sell them. He suggested going "across the road" (Currys) and the said, "Naw - try Comet!"