Help required please

[Csteve2409]

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]

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?

 

[Csteve2409]

Hello, many thanks for your reply.

This is the copy of the details you get with the Vellemans kit.

Many thanks.

 

[KeepItSimpleStupid]

I found this: https://www.automation24.com/multif...reviewPriceListId=1&refID=adwords_shopping_US

it's fairly cheap and has a wide supply voltage, but >=12V DC.

The DIN rail and mounts will cost a few extra dollars. https://www.winford.com/products/dinr.php

Timing >seconds is "harder" because the product of R&C (seconds)using practical resistors and capacitors don't cut it.
10 M ohms and 2 uF. So, you either have to use an oscillator and counter or micro-processor

 

[alec_t]

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.

 

[Csteve2409]

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.