I'm doing a charity project for a local community center. I would like to do a led display that will display a number.
I have 4 tracks that cars will ru down. At the bottom of each track I would like to have the numbers 1-4 and when a kid hits a track number I would like that number to light up. Something like what is listed below. Hopefull I can use a ac source. I can't remember how LED's work. I know that the resistance has to be right but I can't remember any of the equations. Any help would be greatly appreciated.
Thanks
000 00000 00000 00 00
00 00000 00000 00 00
00 00 00 00000
00 00 000000 00
00000 00 00 00
00000 000000 000000 00
Now, that's quite a few leds, if 1 - 4 is the only thing it needs to display you could try hard-wiring the 4 patterns on every matrix. And use diodes to keep them apart
You must have a dc power source to drive leds, but ac is easily converted to dc with a bridge rectifier. The resistance for each led depends on the voltage of the power supply you will be using.
Your power supply will need a bit of punch too. At +- 10mA per led you'll reach an amp quick, so dont get a low current power source