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Old Dec 23, 2004, 07:33 PM
e-flight in 24½th Century
Waldo Pepper's Avatar
Cypress, TX
Joined Jul 2004
525 Posts
?? About LED's and night flying

Decided to try night flying. Right now flying a white foamie, solid wing. Running 2s Lipo's 750 mah with 350 brushed motor.

Would rather fly a shorter time and see the plane than have a set-up that is not bright

Questions:
1. Best orientation of LED's: fuse pointing out to underside of wing? on wing tips pointing back at bottom of wing and fuse? Other?

2. Number of LED's I can reasonably run: remember, brighter is better for me

I've built the RC electronic switch that is posted in this section and it works: have looked at http://www.rc-cam.com/led_info.htm and ordered the brightest and best based on his recommendations so just need to figure placement.

Thanks,

Waldo
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Old Dec 23, 2004, 07:43 PM
Inverted Electric Flyer
tmproff's Avatar
United States, TX, Humble
Joined Jan 2004
499 Posts
Check out this thread I wrote a while ago:

http://www.rcgroups.com/forums/showthread.php?t=298519

I have 11 LED's on my 35" Todd'sModels Attitude, and they drain very little power from the battery.

The brightest I've seen are the 8000 MCD's with at least 40 degree's of visibility, then I sand it all over.....they're superbright from all angles. Just be sure to use the correct resistors. Remember, Green is the easiest color for the eye to see. I've had great luck with both green and red's

BTW, try an LED that blinks 2 different colors, they're really visible
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Old Dec 23, 2004, 07:58 PM
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Wow..im very interested in doing this..for my sky scooter pro2..I have an extra empty input on my planes reciever which is the standard 3 pin servo connector type input...is this were I would plug lights into?? the sky scooter battery packs I have are 9.6volt 1650 mah nimhs...can this work for my plane ???
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Old Dec 23, 2004, 08:14 PM
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what color/strength lights can you recoommend as the brightest...I was thinking of putting stay on lights on the front..and the blinking ones on back...to help with orientation..im color blind..so just doing different colors on front and back would not help me any...please give me advice on how many lights I should get/which ones..and accesories needed to do this project...I have a new cold iron cordless soldering iron,,and would love to try this
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Old Dec 23, 2004, 11:20 PM
RC Outlaw
NitroWatt's Avatar
New Mexico
Joined Mar 2002
370 Posts
I have an Islander (GWS) with full lights. I use the standard full scale scheme. Red on left wingtip, Green on right, flashing reds on top and bottom of fuse, white @ end of fuse (taped a bit so not too bright), and two bright landing lights on each wing. superbrightleds.com/
Green RL5-G5030
Red RL5-R3545
White RL5-W10015
Blnk red RL5-BR2020

I had a problem with the bec shutting down various esc's when plugging the lights into a vacant servo port on the RX...and also I use all six channels on the electron 6 (flaps and bomb release) so I got a radio shack 5V regulator for like a $1.50 and wired it between the battery and esc so it provides a constant 5V to the light system. Part of the problem was that I use 3S lipos...they tax the bec with even 3 servos...not to mention 5.


The whites and greens need a 68ohm resistor and the red needs a 125ohm. The blinking reds are good for 6V so no resistor is needed.

BTW right now their site dosen't list the green part #...just go with the RL5-G5023. I sanded the beacons and navs (red,green) to diffuse the light...helps dramatically...makes them so they're not so directional...able to see them from all angles. The whites (landing) are very directional and its good because they're like spotlights...when the plane comes at you it's BRIGHT...but otherwise at other angles the nav and beacon lights appear brighter. I fly at night all the time and use the plane as a flashlight when I need to go in and change batteries!

Nice Thread TM!!!
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Old Dec 23, 2004, 11:45 PM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Question

After reading the rc-cam site I found that you had to add up
all the LED's Vf values. Most of the LED's had values of 3.7, 3.5,
2.5, etc. So if you have a spare rx servo port available you can
only use that up to 5V.

So my question is do you guys piggy back other ports to light
up the whole thing???

fb


Quote:
Originally Posted by NitroWatt
I have an Islander (GWS) with full lights. I use the standard full scale scheme. Red on left wingtip, Green on right, flashing reds on top and bottom of fuse, white @ end of fuse (taped a bit so not too bright), and two bright landing lights on each wing. superbrightleds.com/
Green RL5-G5030
Red RL5-R3545
White RL5-W10015
Blnk red RL5-BR2020

I had a problem with the bec shutting down various esc's when plugging the lights into a vacant servo port on the RX...and also I use all six channels on the electron 6 (flaps and bomb release) so I got a radio shack 5V regulator for like a $1.50 and wired it between the battery and esc so it provides a constant 5V to the light system. Part of the problem was that I use 3S lipos...they tax the bec with even 3 servos...not to mention 5.


The whites and greens need a 68ohm resistor and the red needs a 125ohm. The blinking reds are good for 6V so no resistor is needed.

BTW right now their site dosen't list the green part #...just go with the RL5-G5023. I sanded the beacons and navs (red,green) to diffuse the light...helps dramatically...makes them so they're not so directional...able to see them from all angles. The whites (landing) are very directional and its good because they're like spotlights...when the plane comes at you it's BRIGHT...but otherwise at other angles the nav and beacon lights appear brighter. I fly at night all the time and use the plane as a flashlight when I need to go in and change batteries!

Nice Thread TM!!!
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Old Dec 24, 2004, 12:52 AM
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Mr.RC-CAM's Avatar
USA
Joined Oct 2001
5,137 Posts
Quote:
So my question is do you guys piggy back other ports to light
up the whole thing???
You use the same Rx servo port (spare or shared) to power ALL your LED's. You can use any combination of series/parallel that supports your LED Vf's and the current capability of your ESC's BEC.

RC-CAM
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Old Dec 24, 2004, 01:09 AM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Wait a min

Most BEC's are 5V so you are telling me that you can do more than
2 LED's that are like 3.7V and 3.2V off one RX port??? I don't think so
otherwise I'm not understanding something here.

hmmm,
fb

Quote:
Originally Posted by Mr.RC-CAM
You use the same Rx servo port (spare or shared) to power ALL your LED's. You can use any combination of series/parallel that supports your LED Vf's and the current capability of your ESC's BEC.

RC-CAM
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Old Dec 24, 2004, 01:26 AM
Registered User
Mr.RC-CAM's Avatar
USA
Joined Oct 2001
5,137 Posts
Quote:
Most BEC's are 5V so you are telling me that you can do more than
2 LED's that are like 3.7V and 3.2V off one RX port???
Each LED gets the appropiate current limit resistor. The LED/Resistor is wired in parallel with others just like it. They all connect to a single Rx port.

The LED qty limit is determined by their combined currents. I suggest keeping it under 150mA and count it all as one servo load. But the specific limit is really up to the BEC in your ESC, which includes any deration that you should apply if high cell counts are used.

More R/C related LED details are here: http://www.rc-cam.com/led_info.htm

RC-CAM
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Old Dec 24, 2004, 01:30 AM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
I think I got it now

So Mr.RC-CAM what's the highest Vf value you had and still stayed
under 150ma???

Festival of lights? So I could parallel any number of LED's which come
under 150ma.. hmmm....

1 RX port ----RED
-----BLUE
-----GREEN
-----WHITE
-----CYAN

Like this??? If so, then how do you solder all those resistors off one
connector to the RX???

curious,
fb


Quote:
Originally Posted by Mr.RC-CAM
Each LED gets the appropiate current limit resistor. The LED/Resistor is wired in parallel with others just like it. They all connect to a single Rx port.

The LED qty limit is determined by their combined currents. I suggest keeping it under 150mA and count it all as one servo load. But the specific limit is really up to the BEC in your ESC, which includes any deration that you should apply if high cell counts are used.

More R/C related LED details are here: http://www.rc-cam.com/led_info.htm

RC-CAM
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Old Dec 24, 2004, 01:41 AM
Registered User
Mr.RC-CAM's Avatar
USA
Joined Oct 2001
5,137 Posts
The Vf does not set the current on its own. YOU do that with your chosen current limit resistor. The current is based on how hard you want to drive the LED, with sane observation of the max allowed forward currents. Almost universally I pick something that is between 20mA and 25mA, which gives good illumination for decent high lumen LED choices. That would safely allow several LED's on your BEC driven R/C Rx.

The RC-Cam link shows an example with two LED's. Just replicate that for as many as your BEC can support. All are wired to the same servo plug using any construction method that suits your fancy.

RC-CAM
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Old Dec 24, 2004, 01:59 AM
RC Outlaw
NitroWatt's Avatar
New Mexico
Joined Mar 2002
370 Posts
It seems that some escs (GWS, Electrifly) have basically the same bec supplies. There are others that have higher bec current ratings (VERY FEW). Typical is 1A...so with a few servos plus a couple lights, a plane, preferably testing on the ground operated with lights and moving the servos around for a minute or so you may find that the esc's bec shuts down the whole show...INCLUDING RX! I learned this the hard way (BUT I'M USING 3S LIPO..it makes a difference to the bec) my plane would do fine and all the sudden the lights would go out as well as everything else!...I'd have to listen for the sound of the crash..because each time (before I figured out the 5V Radioshack thing)..I'd be at least 500ft high at 1 in the morning!!! The bec is totally separate from the motor circuit.

An interesting find...I found that my GWS Islander with 2 M-250s and a 3S 1320 lipo works best from a GWS ICS 50!!!! The ecs is rated 5A max...I'm pulling at least 10A @ full throttle (limit full throt to about 15 seconds)...but ALL IS WELL WITH 3S!!! The electriflys and larger GWS (10A) don't like 3S.

Before trying lights plugged into a servo port do a ground test...you needn't run the motors since it's a different circuit in the esc...but move all the servos around aggressively...feel the esc and if you feel a tiny part of the esc that's hot as heck it's the bec. The bec's seem to be surface mount IC's or fets that aren't nearly as strong as the motor speed control fet's.
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Old Dec 24, 2004, 02:09 AM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Ok

I get it.

Can you just give an example(pic) of a three pronged RX
servo extention with the resistors for like 3+ LED's.

Problem I see is when you choose diff Vf rated LED's it
can get ugly putting something together to make it work.

Thanks,
fb


Quote:
Originally Posted by Mr.RC-CAM
The Vf does not set the current on its own. YOU do that with your chosen current limit resistor. The current is based on how hard you want to drive the LED, with sane observation of the max allowed forward currents. Almost universally I pick something that is between 20mA and 25mA, which gives good illumination for decent high lumen LED choices. That would safely allow several LED's on your BEC driven R/C Rx.

The RC-Cam link shows an example with two LED's. Just replicate that for as many as your BEC can support. All are wired to the same servo plug using any construction method that suits your fancy.

RC-CAM
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Old Dec 24, 2004, 02:31 AM
Registered User
Mr.RC-CAM's Avatar
USA
Joined Oct 2001
5,137 Posts
Quote:
Can you just give an example(pic) of a three pronged RX
servo extention with the resistors for like 3+ LED's.
There is a detailed graphic on the listed web page that shows two LED's wired together to a 3-pin R/C cable. Just imagine a third LED there too.

Quote:
Problem I see is when you choose diff Vf rated LED's it
can get ugly putting something together to make it work.
This is neither a problem or a worry, and it is not an ugly process. The resistor is computed for its mating LED using the source voltage, desired current, and the LED's Vf spec. Just plug the Vf into the RC-Cam online LED calculator and let it tell you what resistor to use. You can parallel a group of these LED/Resistor combos together on a single Rx port.
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Old Dec 24, 2004, 02:44 AM
Flying motor mount master
fly_boy99's Avatar
San Jose, California, United States
Joined Oct 2004
8,745 Posts
Last try...

Yep saw the graphic but I'm thinking of an example like this.

I have 4 LED's to run off one Servo RX port. Each LED is a diff
color and different Vf. (3.7, 3.2, 2.5, 2.0 respectively)

I have a positive, negative, and whatever the third one is.

Here's my positive lead with their resistors.

-------------------------------- <<<< wire here
| | | | <<< resistors here
3.7, 3.2, 2.5, 2.0 <<< LEDs here

As long as I stay below the 5V BEC cutoff then I'm golden. The comment
I was trying to make was soldering the resistors down the positive
wire and not making it ugly.

yep?
fb

Quote:
Originally Posted by Mr.RC-CAM
There is a detailed graphic on the listed web page that shows two LED's wired together to a 3-pin R/C cable. Just imagine a third LED there too.


This is neither a problem or a worry, and it is not an ugly process. The resistor is computed for its mating LED using the source voltage, desired current, and the LED's Vf spec. Just plug the Vf into the RC-Cam online LED calculator and let it tell you what resistor to use. You can parallel a group of these LED/Resistor combos together on a single Rx port.
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