Thanks a TON ya'll, it works really well...maybe I need to buy an electronics book..... Jonathan -----Original Message----- From: Ernie Murphy To: PICLIST@MITVMA.MIT.EDU Date: Friday, June 11, 1999 1:28 AM Subject: Re: multiplexing 7-seg LEDs >The 2nd resistor from base to ground is usually a good thing, but redundant >here, as the same base drive resistor gets grounded and hence provides this >path. Save a few cents and some real estate. > >When sizing the common element drive resistor, remember that for X display >digits each will be on for 1/x of the time, so you want to give them X >times more current for everything to work out. (Huh? If the normally look >good at 20mA, and you have 5 display digits, drive them with 100mA for 1/5 >the time.) > >Enjoy! > > > >At 10:08 PM 6/10/99 -0400, you wrote: >> Jonathan; Man, I really like this transistor stuff. With common anode, >>you must supply plus 5V to one of the commons and group the segments >>(including decimal) into a group of eight, which go through a group of 8 >>resistors, probably 220, 270, or 330 ohms. It doesn't hurt to add a >>nuther resistor from base to emitter, to squash bleed currents that cause >>glimmer. You save a resistor or 2. Then they are brightest. >> HP's are not all that bad. you use tris alot. Chris Eddy Jonathan >>Newport wrote: Thanks. Jonathan Newport >> >