Search found 4 matches

by FredS
Fri Mar 22, 2002 2:34 pm
Forum: General Discussion
Topic: Single IC to run a 7 seg LED display?
Replies: 2
Views: 1620

Single IC to run a 7 seg LED display?

Has anyone ever heard of a single IC that will run a 2 digit, 7 segment LED display? If not, then how about a single IC that can will control 1 digit, with the capability to cascade a second chip to control the second digit? I don't need no stinkin' decimal points or lamp test function, so it doesn'...
by FredS
Fri Feb 22, 2002 10:36 am
Forum: General Discussion
Topic: momentary signal to a shift register - how?
Replies: 9
Views: 2810

Re: momentary signal to a shift register - how?

I understand that I need some change to trigger the 555, but it doesn't seem to work correctly with a change from low to high with the switch. It works sometimes, but not always. To work consistently, it seems to want 2 changes – low-to-high, then high-to-low (or high-to-low then low-to-high).<p>I’l...
by FredS
Wed Feb 20, 2002 10:38 pm
Forum: General Discussion
Topic: momentary signal to a shift register - how?
Replies: 9
Views: 2810

Re: momentary signal to a shift register - how?

Thanks guys, but...<p>After my original post, I found the 555 info on Tony's site as suggested by Ron. I've tried making a one-shot by using a 555 in monostable mode as shown there, but I can't get it to work consistently. Once it starts, I'm feeding a signal back to the 555 to reset it instead of u...
by FredS
Wed Feb 20, 2002 10:26 am
Forum: General Discussion
Topic: momentary signal to a shift register - how?
Replies: 9
Views: 2810

momentary signal to a shift register - how?

I'm building an LED back/forth sequencer based on 74LS194 bi-directional shift. I have a problem because the sequential outputs (A,B,C,D) stay high until reset, but I need them to go A high/low, B high/low, C high/low, D high/low, then reset. I've found that I can do this if I send a high signal fro...