Rotating Police Strobe Lights Effect

[Darkowski]

Hello!

I'm looking for a diagram to create a rotating effect for the lights of my Ecto-1a build.

For example grouping 4 SMDs in a square with a chasing effect that creates the illusion of a single rotating light...

I know how to create a chasing circuit using 10 LEDs with a 555 and 4017 chip, but I need a few sets (12 I think) of 4 LEDs each.
I don't want to use 12 separate circuits lol

Thank you!

Darek

[EVApodman]

How many rotating strobe lights do you need. I'm guessing four from you message. It is possible to run four light from each output of your driver chip if they are wired in series, keeping the line current low.

This will give you four lights all turning at the same speed. I would vary the positions of the starting light to avoid a "synchronized" lighting effect in all four.

If this circuit still doesn't look right when operating then two or more timing and drivers circuits may be necessary to get the right individual rotating speed variation.

[Darkowski]

Thanks for the help EVApdman.

It's 12 rotating lights, each rotating light made up of 4 SMDs. So 48 SMDs in all lol
I'll probably have to make 4 or 5 circuits.

I actually didn't think of wiring 4 SMDs in series! I was thinking of wiring them in parallel, but was worried about the amperage.
But if wired in series, the amperage stays the same, right? Still new at this

[tetsujin]

I think wiring the LEDs in different clusters together in series sounds like a nightmare, personally. It means that instead of running 5 (or even just 4, if you want to deal with the headache of trying to wire the LEDs into a series loop) wires to each group of 4 LEDs, you now have to run 8, and have most of those running to neighboring LED clusters. I can't imagine it's worth the trouble. At least, not unless your

I have been working on something like this myself, but using clusters of 6 LEDs, with each LED paired with the opposing one (in parallel, because I don't need the extra complexity of wiring them up in series) - I've found it to be really difficult personally. I've attempted several (using 0.8mm wide LEDs), and only managed to build a few that worked and looked good enough to be viable. I've found it hard to get them arranged together and to make the solder connections without everything coming apart under the heat. I'm curious about how you're building your LED clusters.

The ones I built were also arranged so all the wires come out of one end (the bottom) - that's another potential complication of having the clusters wired to each other in series, it becomes harder to get all the wires out the bottom if more of them need to attach to the top. (But having the LEDs in series does make it easier to use your battery power more efficiently...)

Why not use transistors? Connect each output from the 4017 to a transistor and use the transistor to switch power on/off to the LEDs in all those strobes. You don't need additional ICs, the transistors should be able to switch enough current to drive 12 LEDs in parallel.

[Ant]

I've done something like this, but will echo the comments that it is extremely fiddly!! it was only one beacon, and was driven by a microcontroller, but I did manage to get a light cluster around the size of a 5mm LED.

1st Prototypes

https://vimeo.com/129956163

Final go

https://vimeo.com/130010713

The software fades each LED up and down to help smooth the transition between them and improve the rotational effect.

(Yeah, I know some of the sizes quoted in the video are wrong - that's what happens when you mix metric and imperial )

[Darkowski]

I like that effect Ant!

Except that I need 13 like this one lol.
(thought it was 12, but I forgot one red light on the roof).

I may have found a way, but it will still require 3 circuits. And the wiring will be insane lol

[EVApodman]

I may have found a way, but it will still require 3 circuits. And the wiring will be insane lol

After they drag you off to a padded cell can I have your models?

[Kylwell]

Scroll down a bit http://www.ngineering.com/lghting%20eff ... ilroad.htm

[Darkowski]

lol EVApodman!
If that happens, I'll send them to you.


Thank you for the help, Kylwell. Very interesting projects. The site is booked


Well I found a code for a Arduino for the modern "pulsating" effect that I'll use for the bar above the rotating lights in the front.

As for the rotating lights, I started working on the circuits. I'll have to make 3 independent circuits for the the 12 rotating lights (48 x 0805 SMDs in all).

Here's a short video of the first circuit. The SMDs will still be glued in place. For now they are in the "air". The second circuit will have the green SMDs.
Lots of swearing and sweating, but I'm still sane (EVApodman ).

https://youtu.be/1adbtgzfcKc

[tetsujin]

Video unavailable!

It's cool that the site Kylwell linked has instructions for how to build these - but in terms of how to physically construct them the instructions pretty much boil down to "solder them together". That's the part I've been having trouble with, though: Or more specifically, the problem is that the cluster (clusters of 6 in my case) tends to get broken before I can get all the wires in order and test the thing. Either the solder that's physically holding the thing together will weaken and release due to the heat of another joint being soldered, or a pad will get torn off by the physical process of moving and soldering the wires. It's why I'm trying to come up with a better approach, like tiny little jig to hold the LEDs, or an epoxy that's heat-tolerant enough to hold the cluster together as I solder on the anode wires, or a PCB I can solder everything to... something like that...

[Kylwell]

Which is why I'd just order them. I'm a wimp when it comes to soldering tiny LEDs.

[tetsujin]

Which is why I'd just order them. I'm a wimp when it comes to soldering tiny LEDs.

Well, based on my experience building LED clusters for police lights I wouldn't think less of anyone who chose to buy them rather than build them... But did the site you linked sell the LED clusters? I thought it just sold the driver boards.

[Kylwell]

Which is why I'd just order them. I'm a wimp when it comes to soldering tiny LEDs.

Well, based on my experience building LED clusters for police lights I wouldn't think less of anyone who chose to buy them rather than build them... But did the site you linked sell the LED clusters? I thought it just sold the driver boards.

Yes and has instructions for powering it.

[tetsujin]

Which is why I'd just order them. I'm a wimp when it comes to soldering tiny LEDs.

Well, based on my experience building LED clusters for police lights I wouldn't think less of anyone who chose to buy them rather than build them... But did the site you linked sell the LED clusters? I thought it just sold the driver boards.

Yes and has instructions for powering it.

Yes they sell LED clusters, or yes they only sell driver boards? I see driver boards and I see LEDs but I don't see LED clusters

[Darkowski]

Well, I finally found a way to built the light bars.
Using 3 separate circuits.

I opted for 3 SMDs per light, with 36 x 0805 SMDs total.

Two careless mistakes though..
First one, is that one yellow light in the rear light bar, rotates in the opposite direction lol
The second one is those two green lights rotate synchronously....
But I'll leave theme as is. Still very happy with the results.

Hopefully the link works...
https://photos.app.goo.gl/zTBbpPIIpyW1OOvs2

[EVApodman]

Very nice.Now put inside the model!