http://en.wikipedia.org/wiki/Switched-mode_power_supply
No matter if you're talking about a wall wart or a dc to dc regulator the are very similar. There are variations such as internal fet external fet. Some need the catch diode some don't... If you want to get into looking at the plethora of different controllers I can help you there too... The ones I'm most familiar with are DC-DC regulators but its all based on the same concepts. ~Brett On Tue, 2010-03-23 at 07:33 -0700, Phil Hystad wrote: > An off-topic question. > > Most electronics these days have dual-voltage chargers. For example, my > iPhone, my B&N Nook, and my laptop are all dual voltage. Thus, when in a 220 > volt AC location, all you need to do is plug the unit in using an adapter > common to that location (I was in Paris last week making use of these > dual-voltage characteristics so this prompted the question). > > So, what is the technology of these dual-voltage chargers? I am asking > because they are getting pretty small. The unit for my iPhone is just a > little plastic wrapped container about 1 inch square. My Nook charger is > even smaller in that it is only about 5/8 inch thick by 1 1/4 inch long. > > Both of these units are USP interfaces so I figure 5 volts charging and I > know the Nook charger delivers a little more then the 500 mA maximum of a > typical USB. > > Are these transformer plus rectifier and voltage regulator or are they some > kind of switcher, or maybe just a rectifier diode and voltage regulator. > They do heat up so there is something there absorbing a bit of energy. > > Maybe I need to cut one open but I am not wanting to do that if I can get the > answer here. > > Thanks, > 73, phil, K7PEH > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
