Flashing LED Circuit [Archive]

Lag_Janson

Apr 18, 2007, 09:42 PM

Okay, I'll lead off with the fact that electronics is really not my thing. I'm actually catching on this (third) time around but I rate a beginner in these things and my interest is pretty specific so I likely will not advance much.

I'm looking to put an indicator light (led) on my plane much like the night flyers do. I'd like a short flash, and I've searched the forum so far without success on this aside from getting a blinking led.
A) I want something warning me my plane is still on.
B) Flashing is pretty - I'm drawn to flashy and shiny things.

I've asked a couple of friends (more inclined than I) and they've pointed me to this. http://www.techlib.com/electronics/flasher.html edit: they pointed me to the first circuit diagram on the page...

With a 4.8v or 5v source, and reducing the 470k resistor in the top corner next to the transistor to 43k, would this work for a plane?

rmteo

Apr 18, 2007, 10:20 PM

There are several ways to do this. You can use a 555 timer chip, a small microcontroller, and I believe National made a chip to be used as a lamp flasher. There a also flashing leds that just need to be connected to a power source - however they are NOT very bright and may not be useable for your needs.

Also, one of advertisers on this website, Dimension Engineering, makes some nifty LED lights for R/C use. One of them is here:
http://www.dimensionengineering.com/EasyLights.htm

There are several other styles available from them as well.

mem

Apr 19, 2007, 01:23 AM

RC-Cam has some good info on LEDs here: http://www.rc-cam.com/led_info.htm including an online calculator for selecting the resistor. If you want to build a simple electronic circuit, I agree with the suggestion to use a 555. You can find a wealth of information on this chip in google.

toxicmouse

Apr 19, 2007, 07:37 AM

i would say a flashing/blinking LED is the simplest solution. if you want something a little more unique for $1 try:

http://www.rapidonline.com/productinfo.aspx?tier1=Electronic+Components&tier2=Optoelectronics&tier3=5mm+LEDs&tier4=Rainbow+colour+cycling+5mm+LED&moduleno=75160

this is connected with just a current limiting resistor, so you will not have to do much soldering. all the control circuitry is inside the LED. i have not seen anyone use one of these, be the first in your neighbourhood!

Motions

Apr 19, 2007, 09:54 AM

i would say a flashing/blinking LED is the simplest solution.
I was going to say exactly the same thing. Why make a elaborate circuit just for a flashing LED. Buy a flashing LED and save time, money, and weight.

mem

Apr 19, 2007, 10:56 AM

I was going to say exactly the same thing. Why make a elaborate circuit just for a flashing LED. Buy a flashing LED and save time, money, and weight.First time I have heard a 555 flasher circuit described as elaborate ;)

Anyway, although the linked devices are pretty bright, using something like a superflux LED (http://www.lumileds.com/pdfs/DS05.pdf) can provide greater intensity and much broader viewing angle.

Also, the flash rate and duty cycle can be set with a 555 and it’s a fun and easy introduction to DIY electronics.

But I can’t argue with the flashing LED as the easier option :) .

Lag_Janson

Apr 19, 2007, 11:14 AM

I've actually read rc-cam already, got it bookmarked too. I really like their complete circuit for nav-lights, but really it's overkill for what I'm looking at.

I've also looked at a simple flashing led, but again it's personal preference in the way it blinks so I wandered past that. The rainbow led is pretty cool, never seen anything like that before!

This is actually me "measuring twice before cutting". I wanted just a quick flash and more pause on a high intensity white led. I trust the guys who gave me the circuit, but they don't fly so the receiver is an unknown variable to them. I'm headed to the city this weekend to an electronics surplus store anyway (shrink tubing - handy stuff!) so the little side project doesn't hurt.

The real blame is the Picoo Z knock off I have... The flashing light there is the inspiration for this. (just avoiding the complications of a triple-flash)

Motions

Apr 19, 2007, 12:41 PM

First time I have heard a 555 flasher circuit described as elaborate ;)
Sorry, guess that is the wrong word. I was thinking about designing a PWB, building, calculating component values for timing, etc. versus connecting a flashing LED to a wire.

Yes, the 555 is probably the most simple circuit to design but for an application like this it just doesn't make since....unless you want to play with more ideas.

mem

Apr 19, 2007, 03:09 PM

... for an application like this it just doesn't make since....unless you want to play with more ideas.Its sometimes hard to know if the best solution is the one that is simplest, or cheapest or most interesting. I had a similar desire to Lag to have something like the Picoo Z strobe on all my helicopters. The project escalated to also include a multi color flashing battery low voltage indicator driven by a PIC microcontroller. Overkill, but lots of fun to design and build.

catflying

Apr 19, 2007, 03:16 PM

If you want to use your circuit with 3 cell li-po try to use this circuit
http://www.coolcircuit.com/circuit/led_flasing1/
becuase it use one transistor,capacitor and resistor.
But I not test.

Malc C

Apr 19, 2007, 04:04 PM

If you want to mimic the navigation flash sequence used on full sized aircraft then a PIC is the way to go as you have full controll over the flash period, repetition and sequence the LEDs can be flashed in. If you want to simply add some lights to a model then use LEDs with built in flashers, and if you use 5v LEDs there is no need for a series resistor as this is often built into the flash circuit contained in the LED - simply connect two wires (+v and GND) from a spare port on the receiver.

Kernwrech

Apr 20, 2007, 03:05 AM

I would like to have some sort of sequenced flashing nav lights having a "flash"-"Flash"-"Pause"- sequence. Could this be done with simple component setup or do I need to program a pic for it?

Malc C

Apr 20, 2007, 07:36 AM

You could use an Ne555 and a 4017 decade counter, connect the 1st and 3rd output to the first LED , 5th and 7th output to LED2 which would give a double flash on each. But as I said im my previous post a PIC offers more flexibility, and fewer components

Have a look at the light sequence (http://www.micro-heli.co.uk/lights.wmv) on my old VE heli which used a single 8 pin 12F675 PIC

catflying

May 01, 2007, 09:13 AM

I would like to have some sort of sequenced flashing nav lights having a "flash"-"Flash"-"Pause"- sequence. Could this be done with simple component setup or do I need to program a pic for it?

this circuit may be help you.

Kernwrech

May 08, 2007, 10:44 AM

Thx!

Hmm... And I only need to calculate values for the resistors and capacitors... ok, not a big deal, I have done many circuits with 556...

But the question here was to get it lightweight... Is 556 generally available as SMD?

rmteo

May 12, 2007, 12:20 AM

The 556 is available as a 14-SOIC from both Texas Instruments and ST Microelectronics.

Tomapowa

May 27, 2007, 11:17 AM

MINI-FLASH PC-Programmable 4-Channel LED Flasher/Controller with R/C Control
http://www.diyrc.com/picaxe-miniflash.htm

degreen60

May 29, 2007, 03:18 PM

this circuit may be help you.

Something as simple as this does not need to be built on a board. I build them dead bug style(lay the chip with pins sticking up and solder components to the pins). Cover them with tape or heat shreak tubing.

samtheboxer

May 31, 2007, 03:08 AM

I have a similar circuit that works great, ill post it when i have a chance (maybe tomorrow).

Just a quick question, how do you wire this into the main battery without interfering with the rest of the planes circuitry?

gpi777

Jun 28, 2007, 11:50 PM

gpi777

Jun 28, 2007, 11:58 PM

this circuit may be help you.

Could you please give some values of the Caps and resistors to simulate the doulble strobe effect of a real aircraft.
Thanks

MikeDD

Jun 29, 2007, 03:04 PM

http://cappels.org/dproj/ledpage/leddrv.htm

ebraganza

Jun 29, 2009, 05:02 AM

Malc C

Jun 29, 2009, 12:36 PM

Edward

The Hex code and schematic can be downloaded from http://www.micro-heli.co.uk/Navigation%20lights.zip

It's simple to build, but you will need a PIC programmer to load the code into the 12F675 microchip

mrblucor

Jun 29, 2009, 11:27 PM

Hello All,
I use these. They run from 3 to 10 Volts, they're bright, they blink, and they're cheap.
https://www.superbrightleds.com/specs/brb2020_specs.htm

JB

Slider2732

Jul 02, 2009, 10:52 PM

And another idea, with variable rate flash, duty cycle changeability and 2 seperately running LED's from one 8 legged chip, is the comparator oscillator.
Though not normally used for oscillator circuits, I found myself looking up a C393C chip, having found 2 on a circuit board. They run from 2V and have 2 comparators on them...this translates as 2 flashing light circuits, with the 3or 4 resistors and couple of capacitors. Using 1/8th watt resistors, much can be placed on top of the chip in fact.
The circuit diagram to get these running is half way down the page here: http://home.cogeco.ca/~rpaisley4/Comparators.html

I spider legged the circuit and found the 0.47uF cap to flash too quickly. Changed it to a 2.2uF. Then, by chance, I put a 10uF between legs 3 and 4 (Ground), the duty cycle changed to 50/50 from 1/2 sec on/2 seconds off.
Red LED's in the circuit run very well at 3V, as do superbrights.

druzara

Jul 31, 2009, 05:24 AM

This might be overkill for a small model, but this is what I have been doing to my CX2. Has a few more functions including powerful landing light and low battery warning.

Have a look at my Build blog (http://turningaway.net/acholic/?cat=4) if interested.

smudgepost

Sep 16, 2009, 06:05 AM

Hi all, I was hunting around the web looking for some circuit designs and stumbled across this forum. This post seems very relivent though probably more involved than my circuit need.

I wish to make a very very simple first circuit for a prop. It is simply a Red LED that pulses on and off, rather than a strict on/off blink, probably on 1/3 of the time, off 2/3 of the time but is smooth/fade between on/off.

It needs a switch and to be as low power as possible, as I was hoping to hide a watch/button battery in it. Battery life 24-48 hours. The battery time is a minimum but my main restriction is circuit space, as it needs to fit in a watch case (roughly H 30mm x W 35mm x D 8mm)

I need to keep it small and was thinking I could achieve the pulse using capacitors but like I said this is my first project. Can you please help a new chap start a new hobby?