Choosing the right AC-DC Power Adapter

Hi All,

I got the following power adapter which i want to get another one of. Its hard to find the same one, just wanted to know how important the voltage and current is if the power is met?

Thanks

Obviously, the input (mains) side must be the same at 230V.
The output is DC 14.5V which you want to match as close as possible but as long as the current rating is not less than 530mA, any adapter will do. The current rating tells you the maximum you can draw from the adapter so if you use one with a higher current rating it just means a bigger safety margin.

Brian.

betwixt said:

Obviously, the input (mains) side must be the same at 230V.
The output is DC 14.5V which you want to match as close as possible but as long as the current rating is not less than 530mA, any adapter will do. The current rating tells you the maximum you can draw from the adapter so if you use one with a higher current rating it just means a bigger safety margin.

Brian.

Click to expand...

How close would it have to be? Preferrable to be lower or higher?

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the closest I can find is 12V if i wanted to go lower with 600mA or 1.5A or 2.5A? Isnt lower voltage actually bad as much as high voltage?

Have a look at the machine you are plugging it into to see what its specification says. Often they will give a range such as 9V-12V.

Keith

Do as Keith suggests first.

The voltage and current ratings are quite different things and you can't substitute one for the other. Too little voltage will stop your device working properly, too much will damage it but as stated, most devices will work over a range of voltages and a little more or less won't do any harm. I would guess 12V is a bit on the low side when it should be 14.5 though but you might get away with it. Remember that the manufacturer will have allowed for variations in component values and in the AC mains supply voltage but without intimate knowledge of the design it isn't possible to give an exact answer whether it will work or not.

The current rating tells you how much the adapter can supply safely without being overloaded. The actual amount drawn depends on the demands of the device it's feeding. As long as it can satisfy the device it will be OK but using an adapter with higher current rating is fine, it just means there is more available in reserve than you need.

Brian.

It is quite common for DC power adapters to have very poor load regulation. I have seen nominal 9 vdc adapters that actually put out 16 v under no-load conditions. Often they count on the device it is plugged into to have it's own regulator. I can't tell if your 16.5 v adapter is regulated or not. Some probing of the device under no load and under full load might be enlightening.