premelec
Senior Member
I have an 8 digit LED unit from Ebay and the Mysterious Orient which has what seems very strange current draw... e. g. if I blank each digit and then insert 1 2 3 4 5 6 7 8 the current is about 200 ma not changing much with digits added [with low set PWM - 56K R current set] - then the mystery is that as I blank each digit in sequence the current goes very low with the first blanked digit. Is this normal or is this a bum chip? I couldn't find any actual description of the circuitry inside the MAX7219 chip... just block diagrams... Thanks... [PS the unit seems to obey commands correctly].
PPS I tried pulling both [socketed] LED clusters off board and the current is the same without them so it's something in the chip...
ITEM: http://www.ebay.com/itm/171241714572?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
PPS I tried pulling both [socketed] LED clusters off board and the current is the same without them so it's something in the chip...
ITEM: http://www.ebay.com/itm/171241714572?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
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