Long Delay Astable Multivibrator

[rick hardy]

I purchased a light controller board that will will produce multiple patterns; right-to-left, left to right, middle outwards, etc.
The problem is that you select which pattern you want by pressing a pushbutton and that pattern repeats until you press the pushbutton again. I want to eliminate the PB by having a circuit that displays the first pattern for say 20 sec.'s and then go immediately on to the next pattern (w/o having to push a button) for 20 sec.'s,and then the next, etc, and repeat from the beginning.
I was thinking of using a 555 or 556 timer. Anybody have any ideas ?

[Ron H]

A CD4060 might be your best bet. It is a long counter (frequency divider) with a built-in oscillator. You need to replace the switch with a transistor which is driven by one of the counter outputs, but you need to know how the switch is connected before you can do this.<p>[ May 18, 2004: Message edited by: RonH ]</p>