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Help required please

Thread starter #1
Hi to everyone.

I wonder if anyone can help me with what must be a simple answer but can't find any reference or real help on the web?

I'm looking to build an American Don't Walk / Walk pedestrian crossing light. I am looking for the Dont Walk sign to light up for ten seconds and then change to the walk sign for ten seconds. That's about it but I can't find any reference to building a circuit that has this amount of delay time between the alternating led lights. I brought the build it yourself alternating kit but the max amount time each lights up is only about 5 seconds. I'm not the best soldering so any advice on how I can do this would be greatly appreciated.

Many thanks.
 

alec_t

Well-Known Member
Most Helpful Member
#2
Welcome to ETO!
I brought the build it yourself alternating kit but the max amount time each lights up is only about 5 seconds.
Can you post a schematic of the circuit you used?
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
#4

alec_t

Well-Known Member
Most Helpful Member
#5
The Velleman's circuit is not ideal for long time delays, but you could try either :
1) replacing R3 and R4 with 270kΩ resistors, or
2) replacing C1 and C2 with 33uF electrolytic capacitors.
 
Thread starter #6
Thank you so much.

It does not have to be exactly 10 seconds, just around that sort of time delay between each LED lighting. In fact it could be longer. I had looked at a 555 chip (is that correct?) but truthfully I'm a bit lost when it comes to these things.
 

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