555 timer

You can make the 555 pulse into 3 separate pulses using a 4017 chip. The datasheet shows how to set it up so when the third pulse ends, it starts over again.

You probably will need some kind of power transistor to power the lights; the 4017 won't power them. However, the fishtank thing probably had the same issues, so this may not be a problem for you.

Regards, Bob Monsen

"tt" damaged to put back up, but the lights work great. I would like each light

A 555 and a three digit shift register. each pulse of the 555 shift the output by one.

Charles

On Wednesday 22 September 2004 09:40 pm, Charles W. Johson Jr. did deign to grace us with the following:

Actually, either 3 x 555 in a daisy-chain, or a counter and some selector logic, so that it'll be green for, say, 10 seconds, yellow for 1.5, and red for 15, and so on.

Just have the falling edge of each 555's output trigger the next one, with the third looped around to the first.

You would need some kind of startup logic and "forbidden state" prevention, but it sounds like a fun project. :-)

Good Luck! Rich

THREE 555s (plus associated RC sections etc) to light three lamps!?

Bob's 555 (or any other simple clock generator) plus 4017 approach seems the obvious solution. Not only cheap and simple, but also flexible. It could allow gaps if desired between lighting, and/or different durations of the three colours, within the limit of 9 active outputs.

P.S: Can you guess how many harpsichord sonatas are known to have been written by Scarlatti?

BTW (straying slightly OT), can you guess how many harpsichord sonatas are known to have been written by Scarlatti?

Sheesh! 555.

Jon

Correct - you win the prize!

In fact, I'm able to pass on this one to you, which I was proud to receive a few days ago: news: snipped-for-privacy@jmwa.demon.co.uk

On Friday 24 September 2004 10:50 pm, Terry Pinnell did deign to grace us with the following:

None that are known by me. ;-)

Thanks, Terry. I can see you were _fishing_ for just such an opportunity, too! ;)

Jon

If you started now and listened to one a day, I reckon you'd finish on

"tt" back up, but the lights work great. I would like each light to come on for

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For a 555 timer solution have a look at

A suitable driver will be needed for the lamps as well.

Rob.