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Timer circuit to turn on & off LEDs for layout buildings

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  • Member since
    December 2008
  • 2 posts
Timer circuit to turn on & off LEDs for layout buildings
Posted by MadWab on Thursday, December 11, 2008 3:30 PM

Hi all. 

Does anyone have a circuit to turn on & off about 5 LEDs at a time for a preset time?

I have yellow LEDs in my buildings but want to make a circuit to switch approx 5 LEDs on for a time (set by a variable resistor) and off for a time (also set by a variable resistor or can be fixed).

The idea is to have a say 10 of these circuits going on and off at different times and for different durations. The LEDs will be scattered around the layout and will give the illusion that people are going to bed or waking up randomly. the durations for the circuits will be different so that not all the LEDs go on & off at the same time - one set might be on for 2 minutes and off for 3 while another one might be on for 5 minutes and off for 1 minute etc etc.

i have been told that it can be done but don't have the knowhow to design a circuit. i can put a pc board together if i have the diagram.

any help would be appreciated - wayneburger@mailbox.co.za

  • Member since
    February 2007
  • From: Shenandoah Valley The Home Of Patsy Cline
  • 1,842 posts
Posted by superbe on Thursday, December 11, 2008 5:07 PM

Wayne,

My knowledge of electricity is minimal so my suggestion is very basic. I'm sure you will get more sophisticated advice. My suggestion is to put the lights on different power supplies and then plug the supplies into timers. Some timers let you change the on and off cycle every 15 minutes.

Good luck. You idea sounds interesting and would certainly be an attention getter. 

Just my 2cts. worth. Some times advice is worth what you pay for it.

Bob

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, December 11, 2008 6:30 PM

 Rob Paisley's web site has lots of timer circuits. While none are specifically designed for this exact application, many could be adapted. For example, his traffic light circuit turns on 3 groups of 4 LEDs at various times. The default time with the specified resistors and capacitors is way too short to be buildign lights, but by changing those components the time cycle could be lengthened to minutes or even hours.

 Then there is the old school non-electronic way. A slow motion motor (like out of a clock) drives a metal drum that is one side of the 'switch'. A series of brass fingers ride on this drum to be the other side of the 'switch'. Put insulating tape around the drum where you want the lights to be off. You could do the same with a series of disks with notches cut in them, and use a roller-lever microswitch on each one. At the full diameter of the disk the switch is pressed one way, when it drops into the slot it switches which terminals are connected.

                                                 --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    November 2007
  • 1,089 posts
Posted by BlueHillsCPR on Thursday, December 11, 2008 7:36 PM

 Here is a circuit I found that may be adaptable to your application.  It uses a relay but I'm sure it could be modified to suit your purposes.  Hope it helps.

555Timer Circuit

 

Regards,

Kevin

  • Member since
    July 2008
  • 1,204 posts
Posted by mfm37 on Thursday, December 11, 2008 9:14 PM

 Here's a whole page of 555 timer circuits.

http://home.cogeco.ca/~rpaisley4/LM555.html#4
  • Member since
    December 2008
  • 2 posts
Posted by MadWab on Friday, December 12, 2008 3:52 AM

Hey thanks guys - there is one that looks perfect for the job.  i'll play around with the resistor values to get the timing right

 

many thanks.

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