Help with power adapter!!
 

Alright so here I am in Europe. My laptop charger works fine, my camera power adapter works fine... they all go from 110-250V, which the higher is used in Europe.

EXCEPT- My rechargable shaver does not work here! It is strictly 110V.
So I need a way to power this baby up, or it is beard city for me for 6 months.

Looking on the wall wart charger for the shaver, it outputs 3.6V and 1.2 milliamps. Here in Turku Finland I went to an electronics store and found a variety of adapters-transformers. The problem is, that I cannot find exactly a 3.6v 1.2MA output from them. I can get CLOSE, say 3V at 1.5MA or else 4V at something like .5MA, etc. But not exactly.

I plan on buying a local adapter, and just cutting the cord from my North American power adapter and hooking it on to the new one so it will connect to my shaver.

But, how close do I have to get in terms of actual specs, can I go over/under voltage? What about ma? Will something relatively close work for me? Is it better to be under or over?

Thanks

When you see the current (listed in Amps) you are seeing a maximum rating. Current is dependent on voltage being applied to a resistance (the resistance is your razor). Voltage = Current * Resistance. The resistance of the razor stays the same, so if you double the voltage you will double the current drawn. Not good.

Power = Voltage * Current

So back to your predicament. 220V is twice your 110, so in order to deliver the same power (wattage) you must halve the current. So that 0.5A may make sense (it doesn't make sense if it is already DC at that point).

I would think a 4V DC output wouldn't damage the battery. Most products have something called a "voltage regulator" which keeps the input voltage (or output voltage) within a very tight range (a few hundredths or less of a volt). You are taking a slight chance though as you were not meant to 'fiddle' with it. Buying a converter is a sure bet.

--Joey

Hey Joe, thanks for the advice. Basically I still need a little clarification -

Does the original input specs of the power adapter still matter? This may sound confusing, but should I just worry about what the device "wants"? and not about what the adapter used in North America?

Should I not try and find an adapter that offers as close as possible to what the device wants? That is 3.5V @ 1.5MA? OR, according to what you are saying.... I should search for something 3.5V @ .75MA ??
Is it better to under shoot or over shoot in terms of voltage and MA? I could get close at 3V .5MA, at least as far as what the electronics stores in this small finnish place offer. I will look again for a more closer adapter when I am in Helsinki this weekend. I know that by operating it at different Vs and such, you take a risk - aka reducing the life of the battery - but I dont really care, as long as it lasts a few months.

Any more advice? thx

OK I skipped all the electrical talk :confused: but after all this trouble wouldn't it be worth it to just buy an electric razor w/ a European plug?

^ ^ I agree!!

Right. Get the voltage as close to 3.6V as possible (3.6 is fairly common you should be able to find it). Good luck!

--Joey

I have to keep this shaver going. It has never let me down or abandoned me when the going got hard, so I will not to the same to it... to her.

:batman:

Alright, so I will try and find a 3 or 4 volt replacement power. Milliamps don"t matter? Or do they scale with the voltage as a constant?
Thx

^Yes, the current scales linearly with the voltage (that is double the voltage double the current, halve the voltage and you'll halve the current)

The only thing I would pay attention to regarding current is how much your razor draws. Let's say it 2mW. P = VI so 2mW = 3.6v * I thus I = 0.56mA

So now let's say you get a 4V adapter your current will be 4/3.6 * 0.56mA = 0.62mA. If for some reason your 4V adapter had a current rating of 0.6mA you might have a slight problem. If it has a current rating of 0.75mA then you are in the clear.

Typically the plug off an adapter corresponds to the voltage so be prepared to strip the wires and do a little rigging :)

--Joey

Hey man, thanks for all the help!!!!

Alright, so positive and negative polarities matter?
I do not have access to a test light or multimeter, so any easy way to tell without starting a fire? I mean for when I splice, im guessing the wires comin outta the adpater dont necessarily match, the left and right prongs of the plug.

You got it. The polarity won't matter (likely) because either it is right and it charges, or it is wrong and it won't (just flip it).

I think I am going to clean this explanation up and sticky it since the issue comes up frequently. Good luck!

--Joey

Good idea !

:wacko2:...very very generous of you, for those of us with normal IQs... :insane: