----- Original Message ----- From: "Lindy Mayfield" Subject: RE: [EE] Will phone charger work as a 5v DC power supply? > May I ask what "regulated" means? I'm getting a feeling from this thread that it means that it stays steady at a certain voltage. But I'm thinking, if it is 5 volts, then how would it change? I'm seeing it has something to do with load, but I'm not quite getting it yet. Typical wall warts put out a LOT more than their rated voltage under no load. It wouldn't surprise me to see a "5 volt" wall wart put out 10 or even 15 volts with no load. Many of them will drop close to their rated voltage with relatively little load, but some take quite a lot of load to get into the neighborhood. Since they are intended to work with a particular piece of equipment, you might well know the load will be relatively constant, so why pay for more regulation than you need. > Sorry if this is a dumb question, but is a battery regulated? (I realized that the battery goes down slowly over time. But we are talking seconds here I think, no?) A battery acts a lot more "regulated" than the typical wall wart. A battery's voltage will drop with load, too, but the drop is quite small. > Is this a similar problem to why those small wallwart sized 220 to 110v converters say that they cannot be used with electronic things? More likely it is the noise. A lot of equipment expects the power to look something like an AC power line, which is a pretty good sine wave. A converter likely will have a square wave output, and it may well have an asymmetrical square wave. A motor, for example, won't really care if the peaks are way too high as long as the average is in the ballpark. --McD -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist