7 segment led display driver help?
Ive looked all over, and have already tried 3 circuits, but none work. They have either the wrong ic, wrong led display, etc. So, I want to make a circuit that, by using a decoder, I can flip 4 dip switches and make the display make certain numbers. I have a 7447 ic, common cathode led display, but I can only either find a circuit with a 7447 and a common anode, or a circuit with a common cathode but a different decoder (a latch/decoder/driver). Here is the first site I tried:
And when I finally flip the switches, nothing happens even though I made it exactly as shown. But it has a CMOS, so thats probably a big problem. I also tried this site:
But it has a common anode, and when I tried it it didnt work. I have exactly ELS321HDB. And I have a power unit that can go from 5 - 18 volts. Can anyone show me how to make this? Im not too good yet at reading circuit diagrams, because I seem to make it way more complex then it should be.