If your multimeter can measure AC volts, you can see if you measure any ripple or noise on the wall-wart output, even without a scope. What was the part number of the wall wart? Sean On Wed, Jan 23, 2013 at 2:32 PM, William Bulley wrote: > According to Marcel Duchamp on Wed, 01/23/= 13 at 11:47: >> >> You could get the same results from a supply that is nothing more than a >> step-down transformer followed by either a half-wave or full-wave >> rectifier. The average voltage may well be 4.5V; this says nothing >> about peak voltage. And yes, Digikey and many other vendors do sell >> wall warts that operate like this. > > Thanks. So looking at the 4.5 VDC with an oscilloscope looks like > the next step. If the 4.5 VDC is shown to not be so DC as one would > like, what should I do? If I toss the DigiKey el-cheapo wall wart, > what should I replace it with? And what about the previous comment > about "blowing out the LEDs" if the replacement power supply can not > emulate the internal impedance of the AA alkaline cells? > > Regards, > > web... > > -- > William Bulley Email: web@umich.edu > > 72 characters width template ----------------------------------------->| > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .