Switching Plane LEDs on and off?? Possible?

[Jimd0586]

Hello all!

I recently got into the RC hobby and love it. I have a SuperCub S. I bought an 8 LED Nav light setup which has been installed and plugged into the Cub's stock rudder port (the rudder controls are actually plugged into the aileron port on the receiver). I have a Spektrum DX6i Transmitter bound to the plane.

My questions are: Can I set my receiver to turn the lights on and off? Can I specifically turn just the two landing lights on and off?


Do I need separate gear to get these functions working? (If so, what... 6channel receiver? ESC?) Everything works fine now, I just would like the option with my transmitter.

Thanks!
Jim

 

[Epitaph]

You would need to add something like this to be able to turn it on and off from the transmitter... You would have to seperate the lights you want to control via the switch and run them through this, and the others just plug them direct.

You CAN make a remote switch out of an old broken servo (if the servo is broken of gearing or motor nature) by setting the internal pot to the switch "off" position so that the voltage out of the positive and negative of the motor connection is zero, connect the lights positive and negative to where the motor used to be (only possible with brushed servos... brushless ones no good), checking the polarity, and away you go: when you flip the switch, the voltage is sent to where the motor used to be, which is now the LEDs and light them, and seeing as the pot is never turning it will never reach the "end", so it will be like a constant running motor. When you switch the switch to the off position, the pot is already set into that position, so the board thinks the motor is in the correct place so stops sending voltage, effectively turning off the LEDs... The only thing is you would have to check the voltage output of the board as it varies depending on servo size, make and model.

Good luck!!

 

[robschonk]

Not only possible, simple and cheap.

http://www.hobbyking.com/hobbyking/store/__8833__Turnigy_Receiver_Controlled_Switch.html

 

[Tactical Ex]

This link and corresponding video should be all you need. I've paved the way for you with the help of this great community.

http://forum.flitetest.com/showthread.php?8638-Help-me-complete-my-lighting-diagram-please

 

[Jimd0586]

Thanks everyone! This community is Great!

 

[Jimd0586]

Yeah, just thinking about it... the switch you both suggested is probably the best idea. I have no soldering equipment so the idea I have is to buy a second light kit identical to the first I already have installed. Have the first controller from the kit plugged into the throttle port on my four channel receiver and connect all lights (red beacons, white strobes, red and green nav lights) EXCEPT the two landing lights to that controller. Next take the controller from the second kit and plug it into the rudder port and through the switch you two suggested and plug the white landing lights to that. Set up my DX6i somehow to give rudder imput 50% signal (can that be changed to a switch?) and then I would have landing lights...

Another idea: maybe reverse the wires on the switch so when the throttle drops below 50% the landing lights come on?

I know little about electronics so I'm picking all this up as I go.


(This is essentially the light kit I have installed right now. I just used a y harness from my aileron port (my rudder is connected to that port currently)

 

[Tactical Ex]

I know its not always fun to learn a new skill but I think (judging by the complex plan you have for two sets of lights) you are more than capable of picking up soldering very fast and it would probably be less of a pain for you to just buy a cheap soldering iron set and spend 30 minutes on YouTube learning how to solder than try to rig up what you explained in the previous post. This hobby is hard to grow in without basic soldering abilities. It depends on your preference but you seem to be inquiring on a path which will lead you to many more hours of tinkering rather than plug and fly stuff, knowing how to solder and having the tools to do so will make that experience much more fulfilling.

In all honesty I learned how to solder and bought a cheapo soldering iron in January of this year just for the RC hobby and I am terrible at it but I've never had a mechanical failure due to a bad solder job so you should be fine.

With the part everyone listed it is super easy to program your Tx and you can even follow the diagram the community helped me solidify in the post I linked.

Do what you think is best for you but IMO, start soldering, you wont regret it.

 

[Jimd0586]

Thanks Tactical EX! I think I will begin looking for a soldering kit!

 

[Jimd0586]

Tactical Ex,

Ok. One final question for you. Even if I solder myself, how do I go about diagramming and connecting all these lights up? I suppose I could use the old controller for everything but the landing lights... thus the Nav lights would be on all the time. But the landing lights would need to be wired to a switch... then there becomes issues with voltage changes and amps straight from the battery/receiver what have you. I guess what I am asking is: how would you setup this? hahaha!

 

[Tactical Ex]

I'd have to see the specs on the lights you currently have to tell you "what I would do" so if you have a link to what you are currently working with that would be a huge help.

Right off the bat, if you have 2 extra channels, 2 Tx switches or dials and 2 turnigy onboard switches then each set would be given the duty of controlling 1 set of lights and that way both would be controlled from you Tx.

I wouldn't mind always having the nav lights on personally so I would probably just make sure the LEDs for nav use a 5v power source and plug them into any free channel on my Rx or use a Y splitter from a channel that is being used if I didn't have enough free channels. For the Landing lights I would rig them up exactly like my Blunt nose versa lights in the forum entry. If they are not 12v but 5v then I would have to come up with a slightly different wiring harness to direct power.

 

[Jimd0586]

Tactical Ex,

Thanks again for responding. Yes, I agree with your second suggestion: Nav Lights always on (2 white strobes, 2 red beacons, and 1 solid red 1 solid green light). I would leave those lights connected to the yellow control box pictured and plugged into an open Rx channel or through a y-harness. I would like to have the landing lights hooked up through an ESC to a separate channel to be turned on and off.

However, its the landing lights that make this more difficult. I know little about voltage and amps. I am unsure of how to determine what the voltage is for each LED. From what little I know, even if I have an ESC correctly installed to the two landing lights, I still may need some sort of resistor prior to soldering directly to the landing lights or I may blow them. What I found online about my lights reads as follows:

Specifications:
Input Voltage: 4v-6v
Current: 30mA
Main Control Board Size: 35x24x8mm
LED lead length: 600mm/pc
Weight: 35g

That being said, it looks like the two landing lights require 5 volts . So I would need the ESC switch from the receiver running through a resistor? A video here describing amps etc... https://www.youtube.com/watch?v=7PzohqhABj4

So I guess it matters what voltage my receiver works at? Each light will draw 30ma, and because there are two in a series, that would make it 60ma... ?

I'm know I'm trying your patience here, but I figure once I am able to understand how this all works once, I will have the tools necessary to do it by myself completely in the future. I just don't know where to start.

 

[Jimd0586]

Actually, this entire thing is a little confusing now. OK, so this site provided me with some basic wiring info and guidelines for voltage and amps... http://www.rc-cam.com/led_info.htm.

My supercub 4 channel servo is likely 4-6 volts per channel slot. The lights all work fine. However, how is this possible? That is eight LEDs that would each draw somewhere between 1.5-3 volts... far beyond the servo ports 5 volts... This is where I am a little confused. By my calculations, two bright solid white lights would likely draw 3 volts each... in a series that is 6 volts... pushing the limits of the servo channel a bit if I separated just those two lights off on their own with an ESC switch...

That's where my confusion lies...

Derp Derp... wait, or does it work because the lights aren't in a series but are parallel... thus the 4-6 volts works for all 8 LEDs...?

 

[Craftydan]

Jim,

It's not the voltage that will get them, it's the current that they draw, and too much of that and your RX will brown out. One leg of modestly powered LEDs in series are going to pull in the neighborhood of 20ma, which is not a whole lot, but can add up. If too many are put in series, the voltage drop divided across each of them won't be sufficient to turn them on . . . but on the positive side, the current draw drops dramatically too

Do you happen to have a multimeter? I'm curious about the wiring on the little distribution block, and if it's wired the way I think it is, it won't be hard to add on a RX controlled switch that can turn some on/off, while leaving the rest unmolested . . . but I'd need you to take some measurements . . .

 

[Jimd0586]

Craftydan,

Thanks for the response here.

I don't have a multimeter. In fact, on a graduate student budget I have little money for anything. I suppose that, along with a quality soldering iron, a multimeter is a must have.

In hindsight, I should have probably bought a lighting kit for an extra $10 bucks that included an on/off feature... but I didn't think I needed it at the time. Now that I have the lights installed, I want to experiment and hopefully add a touch more authenticity to my super cub and learn about wiring while I'm at it.

Additionally, I only have the Cubs stock 4 channel receiver with my DX6i. So, I'm not sure I even could run a switch feature through the rudder port and actually use it on my transmitter. (I'm sure there is a way to manipulate the DX6i's rudder gimbal to work as an on/off switch though, right?).

My guess is craftydan, that you would leave the light setup connected the way it is and somehow insert a switch between the LED control box and ONLY the landing lights?

Again, I thank you guys for being patient with me here. I suppose I should have taken high school shop class a decade ago!

Jim
Aspiring RC Pilot

 

[Craftydan]

Jim,

there are SO many classes I wish I took and soo many I wish I hadn't wasted my time on . . . I hope you have better luck in your grad program than I

For now, wire in the lights. if you've got a single unused bullet connector pair and can borrow a multimeter from one of your sparky-geeky friends, we can look into wiring up something that will allow you to turn them on/off on the ground, which later would become a connection point for the receiver controlled switch.

if you can borrow one, with everything unplugged, check the conductivity between all the negitive pins (black wire). check also between the positive pins. I have a feeling that one or the other are all connected together, but it's hard to say without testing it.

Next, power the distribution board with the LED's disconnected, and measure the voltage between the battery's ground and both pins (one at a time) on a blinky light's plug (be CAREFUL to not short them together with the meter probe). repeat between the battery's positive terminal and both pins on the same light.

Come back with what you've found out (if you can) and we can help you know how to wire in a disconnect plug, that can later be used to wire in a remote switch.

 

[Epitaph]

If you're going to put that many leds on the receiver circuit instead of it's own power circuit it might be a good idea to put a nice size capacator in parallel to help prevent brownouts...

 

[LordGarak]

Capacitors won't be much help as the LED's are a constant load, they only help with intermittent loads. I would suggest putting in an over sized BEC or even a dedicated BEC for the lighting.

 

[Tactical Ex]

Jim, don't worry, when it comes to helping within the FT community my philosophy is ... "In for a penny, in for a pound" so my patience here is rarely tried. However, the more informed users have jumped into this discussion to help you and have far exceeded my ability to advise so I'll be watching from the back seat unless I have relevant input.

The good news is all of your LEDs are requiring the same voltage so you'll probably be able to use a common power source whenever the logistics are worked out.

 

[Jimd0586]

Thanks guys. Im going to my cabin for some float flying over the weekend, but when I get back I'll take the next step on these landing lights and the multimeter.

 

[Salty Dog]

I skimmed the posts so hope I didn't miss anything.

IMHO that light kit is nothing to worry about, unless you want to have a switch just to have it. I have that kit and have played with it on a few of my planes. I don't think you will notice any difference in flight time in the day with, or with out the lights.

I have a friend that installed a simple electronic switch from radio shack on the side of his plane to turn his lights on and off. I don't see why you could not put an electronic switch between the controller leads and the landing lights if you want to have them controlled by a free receiver channel so you can turn them on when you want to land, and have the others on full time.

Anyway, I really like this light kit and would like to see some picture of it on your plane when you get it setup.

Good luck