OK, I have a quick question... Why do some "wall wart" power adapters (transformer from AC to DC) work with 110v/60hz and 220v/50hz.. but others do not? Don't they all have the same electronics inside, with the only difference being the output voltage and amperage? Don't they all use the same sort of AC to DC conversion that would work with both input voltages/frequencies? Is the only difference that some are marked to work with both, and others are not? In other words, am I safe to plug in my power adapter for my router into 220v/50hz even if it isn't marked for 220v/50hz? (I bought my router in Canada, but just moved to France, and I didn't bring a power convertor because all my other adapters say they work with both voltages and I just assumed this one would work, too...) It DOES say that it is marked for 110v 50/60hz, which is kind of strange since we don't have 50hz in north america... so why would they indicate both frequencies but only one voltage? Thanks for any help.
Because some contain circuitry to take both, others don't. No, no. No. No. No, its likely to blow up if its not rated for 220. because its has the circuitry for both 50 and 60 Hz but only 110v.
OK, thanks very much. I guess I'll probably have to get something like this shipped to me in France. (About $50 USD after shipping...) http://www.amazon.com/gp/product/B0...7966?v=glance&n=172282&s=electronics&v=glance Cheers!
Actually, most wall warts don't use circutry, but rather a transformer, which has a number of turns of wire on it for a specific voltage. To change the voltage, you need to change the number of wire windings. The reason for the 50/60hz markings is that things like the converter that you linked to do not convert frequency, only voltage. In other words, it outputs 110v @ 50Hz, or 220v @ 60Hz, depending on the input.
Its pretty simple, ones that say 110V only, or 220V only are typically based on transformers. Double the input, double the output, halve the input, halve the output. The only thing frequency should affect there is the amount of ripple, not too much of a problem. Adaptors that are for both 110 and 220 are most likely a switch-mode power supply, frequency could possibly affect the design a bit more with these, but it should be labeled for you to know. Switch-mode power supplies use capacitors, inductors, transistors, and a controller chip to keep the voltage output constant regardless of the input, to a point anyway.
The ones that do both voltages use a switch mode power supply which are pretty flexable about their input voltages. The ones that cannot are basically a transformer, bridge rectifier, RC ripple filter network, and maybe a regulator. They can take both 50 and 60 HZ because someone set up the RC ripple network to handle 50hz. You can replace the power supply with a generic one so long as the polarity and voltage are the same, and it's output current rating is the same or higher as the power supply you are replacing.
I'm sure they have transformers in france that would be suitable... They have electricity over there don't they? *grin*
Ok, here's another question - similar in nature. The adapter that I have for my device says it is: Output: 5.0v / 2.5A I was able to find another adapater that works with 220v/50hz, but the output is: 5.0v / 2.0A Can I use this adapter for my device? Will .5A cause a problem? Thanks!
No, we typically design power supplies to act as a voltage source. This means that it maintains a constant voltage, but have a variable current output. The current rating is the maximum current the supply can source at the given voltage before it damages itself. IF a device uses less current than the maximum rated current, then only the desired current is supplied, not the full current that a supply is rated for.
Sometimes regulators can accept quite high voltages and take them down, albeit generating quite a bit of heat. The ones I found can go from 35v down to 5v. So I'm guessing they have a 20:1 transformer or something of the sort, and whether it's 6v or 12v, it will still be brought down enough... (This is wild speculation, as I really don't know anything of the sort, aside from what I've read in books) You can always buy the correct adapter on the internet, and if you have to, just splice the correct plug onto it.
