MrDEB
Well-Known Member
Been working on a 5 x 7 RG matrix using 220 ohm resistors on the anodes and uln 2803 on the cathodes. Everything works fine so I got curious as to current draw. Placed DMM after one of the resistors and one anode. After turning on all five LEDs in this row the current draw is only 3ma.
Must have something wrong with circuit or application of DMM.
NOTE I had the LEDs on constantly, no blinking.
Wonder why the LEDs are not to bright. Brighter than me I guess?
This dosn't compute = 5v VCC - 1v for the ULN2803 should be 18ma w 220 ohm resistor.
Must have something wrong with circuit or application of DMM.
NOTE I had the LEDs on constantly, no blinking.
Wonder why the LEDs are not to bright. Brighter than me I guess?
This dosn't compute = 5v VCC - 1v for the ULN2803 should be 18ma w 220 ohm resistor.