Double flashing LED circuit...

[crazyfazy_7]

Hello. I'm new to this site, so thanks in advance to anyone who chooses to help me! I'd like to make a double flashing LED circuit for my son's firetruck we just got him for Christmas and I can't seem to find a diagram that tells me how to do it. I've found simple alternating circuits, but I'd like to get that "double" alternating flash like are on police cars and firetrucks. I''m also no electronics wiz...just a guy who likes to tinker and make my kid's life a little more interesting! Any help would be appreciated! Thanks!

 

[duffy]

You mean like this blue light on the electric Police Dog?

 

[crazyfazy_7]

..yes. That's exactly it! I'd like to have two lights blinking like that alternating back an forth.

 

[duffy]

You could hook up a 555 to a 4017 Johnson counter with Driver A connected to the 1st and 3rd output, and driver B hooked up to the 6th and 8th output. So it's blink-blink (A), pause, blink-blink (B), pause, etc.

Let me see if I can find a schematic, I think there's one on here that's almost identical...

 

[crazyfazy_7]

I've seen a video of the project on youtube and I think it takes a 555 timer and a 4017 decade counter, but I'm not sure.

 

[crazyfazy_7]

...sorry. They are going to be LED lights.

 

[crazyfazy_7]

Would you have a shcematic of this circuit?

 

[crazyfazy_7]

...sorry, I'm typing faster than I'm reading. Thank you for looking.

 

[duffy]

The basics are on this page -


Let me see if I can get something a little more specific.

 

[duffy]

The circuit I'm thinking of will give this kind of pattern, with this timing, is this about right? This would what you would get off the 1st, 3rd, 6th and 8th outputs of the 4017 and the 555 set to 140 hz.

 

[crazyfazy_7]

That would be perfect! You know excatly what I'm trying to do! If I can get that to work on his truck, we'll both be happy! Thanks for your help!

 

[crazyfazy_7]

If I can get this to work, I think I'll add some on the back of the truck too!

 

[duffy]

Here's the schematic. I thought there was one like this on here already, but I couldn't find it. R11 is variable so you can adjust the speed, 14hz (not 140hz, .gif uses 100th's instead of milliseconds, oops) is about in the middle of the span. I show two sets of two LED's, but you could put several more on each of those transistors (if you want to make it brighter) just add more LED's + 220 ohm resistors on each side like that. The cap voltages are anything above 6v. I suggest 4 AA batteries because that will last longer than a 9V, but you could use AAA's or whatever. The 4017 is counting down from the top in a round-robin fashion, so it's right side on, off, right side on, off, off, left side on, off, left side on, off,off, repeat.

 

[crazyfazy_7]

Thank you very much for all your help! I can't wait to see my son's eyes when he sees the flashing lights on his firetruck! I don't know who'll be more excited, him or me! I've been looking for a while to try to find this shcematic, so you don't know how much I appreciate your help! Thanks again!

 

[duffy]

Don't mention it. Please post a pic when you get going on it!

 

[netatma]

Thank you very much for all your help! I can't wait to see my son's eyes when he sees the flashing lights on his firetruck! I don't know who'll be more excited, him or me! I've been looking for a while to try to find this shcematic, so you don't know how much I appreciate your help! Thanks again!

Wow a LED crazy father like me, Iam also looking to build one for my little one.

thanks all for circuit, but can someone link me to a 12V strobe circuit which i can use in car too

Many thanks.

Atma

 

[sgt-fig]

Hi:
Radio shack have this little book called "engineer's mini-notebooks", one of them talks about 555 timer ic circuits. It has the diagram for an LED Flasher. It's very simple and cheap (about $10). The books are made by ARCHER and Forrest M. Mims, Radio Schack cat. no. 276-5010. There are other simply circuits there, enjoy it!
sgt fig

 

[hackableFM]

Wow a LED crazy father like me, Iam also looking to build one for my little one.

thanks all for circuit, but can someone link me to a 12V strobe circuit which i can use in car too

Many thanks.

Atma

If all you want to do is migrate this circuit to a 12volt system then simply built this one and use a regulator (7805 or similar) between the Sw1 and the rest of the circuit.

 

[magnum 357]

i use a 4049 and 4017 counter and work like a duffy,s diagram