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· Yard Master & Research
12,471 Posts
Discussion Starter · #1 · (Edited)
In the general discussion forum, I promised a part list for the flasher.
Check out the Led Flasher in the General Discussion Forum it preceeds this information.

The preceeding thread.

I have a newer strobe light thread.

I'm leaving the LED, wires, and circuit board to you.
I use a standard board cut down to size with a dremel wheel and bend the leads in the direction I want to go and use a jumper wire as necessary.
Don't forget the 9 volt battery and lead adapter.
For fun, you can use a breadboard to experiment without any soldering

For wire I use 22 guage solid.I sometimes strip the cover off the wire and use it on long exposed leads on LEDS and resistors when assembling a board.

555CN Timer IC 276-1723 (NOT to be confused with the CMOS timer)
10 uf capacitor 272-1025
1/2 watt resistors 220k 271-1132, 2.2k 271 1121, for 19 flashes per minute
100k 271-1311, 10k 271-1126 or 41 flashes per minute

With exact part numbers I don't have to get into electrical specifications of components. At times, that will confuse me.

I use an 8 pin IC socket 276-1995. That way, I can switch the IC for troubleshooting. I place the timer in the socket, after all the soldering has been done.

Ohh Yah, you will need to rig a switch. This is the draw back for a battery system. I haven't used them but a magnetic reed switch woud be nice.
Aside from model RR applications, the unit is portable. It could be used for a halloween costume. Not in the rain of course.

· Yard Master & Research
12,471 Posts
Discussion Starter · #2 · (Edited)
Flasher Variations

555 Timer photo shows an LED and resisitor connected to pin 3 and the positive pin 4(because it is connected to pin 8). LED long lead faces pin 4.

To Alternate the flash (side to side), just run an LED and resisitor from pin 3 tp Pin 1 (negative side).LED long lead faces pin 3.
This will give you a left, right, left etc. of equal time, flash.

To give your LED a strobe look, Install a 220K to Pin 7 and Pin 8, and a 4.7k resistor to pin 2 and pin 7. The best effect is two LEDs connected from 3 to four. Alternating doesn't look good because the neg LED stays on long while the pos just flashes.

Now, We have a slow flash and a slower flash, Alternate, and a strobe flash.;)

LED is directonal with the long lead facing the postive and the short lead facing the negative.

· Yard Master & Research
12,471 Posts
Discussion Starter · #3 ·
Further Variation

Using this flasher set up shown previously, the slowest rate by switching resistors, is 4 per minute. The led is on for 15 seconds and and off for 15 seconds.
This is done using a 1M ohm (Million) resistor between pins 2 and 7 of the timer and a 100k resistor between pins 7 and 8.

To go fast, 400 flashes per minute use a 10K,1k resistor respectively.

· Registered
135 Posts
T-man - as I'm slowly going through the site (previous posts
and all of that) I found your 555 timer posts. Nice! Do you
have various schematics that you use to share? I found some
generic ones on line, but for comparison purposes, I'm asking.

I haven't used a 555 since college. But I am electrically minded
and electricity plays a big part in one of my other hobbies.
Have you considered getting parts else where? I comparison
shopped a handful of parts and is way cheep compared
to RS.. especially if you want to stock up a little on
common parts.

Anyway, pass on those schematics you have, would you?
I was looking at these:

p.s. - come to think of it, I might still have some 555 notes
stuffed in an old text book :rolleyes:

· Yard Master & Research
12,471 Posts
Discussion Starter · #5 · (Edited)
Diagrams etc.

I like the alternate flash for the pumpkin eyes at that site. I have stayed away from transistors and stick strickly to the 555Timer.

Basically I'm self taught as of last winter.
I reference Radio Shack because it's convenient. I'm slowly progressing, and parts are the key.
I use four Kambach books by Peter Thorne that have various projects.
But IC's get obsolete and expensive. The LM3909 was at 9 buck s each! Good Grief. What I try to do is bridge the gap from electronic to Model RR. I use a breadboard and many of times have toasted stuff.I have the parts for a diesel horn generator but that is a winter project. I tried using a reed relay to turn on a flasher 9 volt set up . It tested good but failed on the the track.
I did malke a 5 volt power supply powered from the track DC HO and ran a flashing unit. I will post the project in the future. I'm looking at two projects right now a 1.5 volt power supply to replace the D cell powered from the track. Today I learned about stamp technology. You can program flashing with this stuff. The site is
I think a lot of light with surface mount tech is done with this. It sounds a lot like DCC control.

Everthing else came from Google searches.

I'm sorry to dissappoint you. I had to read a lot and actually combine information from sites to do stuff. It took me months to get the flash rate to change. For some reason I blew up a lot of LED's

If you are interested in something specific PM

· Yard Master & Research
12,471 Posts
Discussion Starter · #6 ·
Completed Flasher

Showing both sides of the completed flasher. The white wires feed two alternating LED's aat 41 flashes per minute. Using 100k and 10K ohm resistors.My soldering tip was blunt so I cut the solder with a dremel wheel.

Thought you would like to see the end product.
Hey side by side. I have no idea how I did it but it looks good.
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