Basic blinking circuit design 3

[Newengkid]

For a miniature model set, I'm trying to make a 3-way (red, green, and yellow) traffic light blink on and off using a basic circuit design.
Green light: Turn on for 5 sec then turn off for 3 sec
Yellow light: Turn on for 5 sec then turn off for 3 sec
Red light: Turn on for 5 sec then turn off for 3 sec
The small lamps are 12 to 16VDC. Was trying to use simple capacitors and resisters
Having problems making it all work. I'm I missing something? If I can rig-up a simple "one lamp blinking circuit" using these components, I'm sure I can figure it all out. Need Help!

 

[itsmoked]

This would be very VERY simple to do with a PIC processor. The smallest cheapest one too.

Whiole not hard..using discrete parts won't be real easy either since only one light should ever be on at the same time. The standard chip people will suggest is the ol' 555 IC but this is probably going to require 2 or three of them and their required CAPs and resistors. Just caps and resistors won't do it.

If you aren't into rolling your own uProcessor solution look at a PICSTAMP.

For about $30 you can get everything you need. You could run crossings and streetlights etc too.

http://www.parallax.com/html_pages/products/basicstamps/bs1.asp

http://www.parallax.com/

http://www.rentron.com/

 

[OperaHouse]

A friend of mine got a traffic light for his shop and he ordered from a magazine a completed circuit board with a PIC processor that did just that for only ablut $14. The input rectified 110VAC and the output was simple transistor. The circuit could be easily modified for any voltage. There was a pot to change the speed. No need to invent the wheel on this one. I thought it was a really nice set up at a dirt cheap price. Bet the design was paid for by a restaurant chain eith cracker in its name. There seems to be one of these lights in every one.

 

[itsmoked]

OperaHouse; Nice info there...be better with a link!

 

[dbaird]

Check the following:

http://home.cogeco.ca/~rpaisley4/Traffic145.html

http://www.armory.com/~rstevew/Public/LED_Ccts/trafficlight.gif

David Baird
mrbaird@hotmail.com
Sr Controls Engineer
EET degree.
Journeyman Electrician.

 

[OperaHouse]

My friend could never remember where he got it when I asked him over a year ago.

http://www.trafficlights.com

has a unit for $44. They even sell the same unit on eBay, last bid $63. See, no one ever bothers to search on the internet. "Traffic light sequencer" turns up 50K of responses. First six pages are relevant to kits and design.

http://www.trainsetelectronics.com

has a universal sequencer for $27. Just to prove that everything you ever wanted is made by, they have a module that imitates the startup blinking or flashing of a defective fluorescent tube.

 

[itsmoked]

I don't need a blinking bad fluorescent module, mine all do that within weeks anyway!!

Good engineering gone bad...

 

[Newengkid]

Thanks Guys and Gals for the reply on "BASIC BLINKING CIRCUIT DESIGN"

Checking all responces....Will post which was best!

Thanks again!!! Newengkid.