Originally Posted by dumbthumbs53

So I can just wire an LED into a servo lead with no resistors? I was under the impression that an LED wired straight to a battery would cook the LED.

It can but here are a couple of thing that my help. You will want to look at a couple of specifications for the LED, usually this is printed on the packaging.

- Continuous forward current (example: 30mA)
- Forward voltage (example 3.5V)

You also need to know the supply voltage being used to power the LED; as an example 6.6V like A123 packs provide.

Once you have this info go to the URL below and plug in the values.

http://led.linear1.org/1led.wiz

The LED wizard app will calculate the resistor wattage and ohm requirements for you. Wire the resistor into the positive side of the circuit and you are good to go. If the LED is going to be on the exterior of your plane get the brightest LED you can. Brightness is usually stated in Luminous intensity or candles; the higher the number the brighter the LED.

On my plane I have a 10 Candella green LED for my system power ON/OFF. It's bright indoors, not so much outside but is it bright enough to see in full sunlight. Also, use a LED with the water clear lens, they work much better in sunlight. Its hard to tell the on/off state when using LED's with colored lenses outside.

Another LED switch option is from Emcotec- they call it a fuel dot switch- it has a red magnetic plug that is recessed into the switch. Pull it out and the switch lights up bright blue indicating the switch is armed. See pictures below.

Capt. Roll,
Thanks for that link
Pete

Originally Posted by dumbthumbs53

So I can just wire an LED into a servo lead with no resistors? I was under the impression that an LED wired straight to a battery would cook the LED.

Unless you find one of the LED packages with a built in resister, you will need something around a 270 ohm 5% 1/4 watt resister in series for proper operation... (6v - .6 = 5.4v /.02 = 270)

http://www.kpsec.freeuk.com/components/led.htm



Scott

Capt Roll, could you explain a little more in detail the values I'd need? For example, I'm using a single Fromeco 2600 lithium Ion for ignition regulated to 6 volts, and dual 5200s for RX on separate switches so each would have its own LED, both also regulated to 6 volts. What does the diode forward voltage & diode forward current represent?

At the risk of asking someone to do all my homework for me, what exactly do I need to end up with three LEDs, one for each RX switch and one for the ignition?

Signed, "electronics idiot", aka "the guy that forgets to turn power off"".

Originally Posted by Philkoury

How about installing a loss of signal alarm, several are available here is one http://www.hobbico.com/radioaccys/hcap0335.html. When no signal is received by the RX this alarm will sound.

One more time; why not use a simple plug and play loss of signal alarm, no leds to messwith, no need to change out a switch, just plug it in and you are good to go. After you land if you turn off the transmitter but not the receiver then the alarm will sound telling you that you have left the airplane on.
http://www.skykingrcproducts.com/acc...del_alarm.html
DIY version http://www.rc-cam.com/lma.htm
http://www.myrcmart.com/rc-lost-mode...er-p-3145.html

Bad Brad Graphics has a heavy duty charge switch with green LED. 22AWG wire, so should be OK up to 50CC size planes. Just put a couple in a new 50cc Yak55. Nice simple no frills switch.

Originally Posted by Philkoury

One more time; why not use a simple plug and play loss of signal alarm, no leds to messwith, no need to change out a switch, just plug it in and you are good to go. After you land if you turn off the transmitter but not the receiver then the alarm will sound telling you that you have left the airplane on.
http://www.skykingrcproducts.com/acc...del_alarm.html
DIY version http://www.rc-cam.com/lma.htm
http://www.myrcmart.com/rc-lost-mode...er-p-3145.html

I like that idea, but I just looked it up and it's only good for 4.8 volts. Won't work in my 35%er at 6 volts.

Originally Posted by lizzardman

Capt Roll, could you explain a little more in detail the values I'd need? For example, I'm using a single Fromeco 2600 lithium Ion for ignition regulated to 6 volts, and dual 5200s for RX on separate switches so each would have its own LED, both also regulated to 6 volts. What does the diode forward voltage & diode forward current represent?

At the risk of asking someone to do all my homework for me, what exactly do I need to end up with three LEDs, one for each RX switch and one for the ignition?

Signed, "electronics idiot", aka "the guy that forgets to turn power off"".

I'll put together a PDF with some illustrations and text on the details. Will try and post it tomorrow.

I run Boomba switches on Rx and ignition. Easy to install and installs in same hole as an HD switch. The ignition has built-in cut-off too. Is programable for voltage alarm also. Check them out, I like them.

Originally Posted by lizzardman

I like that idea, but I just looked it up and it's only good for 4.8 volts. Won't work in my 35%er at 6 volts.

The Skyking product says it will work with Lipo, you would just not have the low voltage alarm... might be worth giving them a call.

Just ordered three of these from Taildragger RC for ignition only on all my gassers. Haven't installed them yet but testing has proven the LED is plenty bright enough to see in sun light.

I plan on using this LED RX Voltage Indicator for Lipoly & LiFe Battery and this can easily show if the rx is On or Off also the stage of LiFe. I had similar items for my 4-5 cell NiMh. http://www.hobbyking.com/hobbyking/s...ge%20indicator

Originally Posted by sacalu

I plan on using this LED RX Voltage Indicator for Lipoly & LiFe Battery and this can easily show if the rx is On or Off also the stage of LiFe. I had similar items for my 4-5 cell NiMh. http://www.hobbyking.com/hobbyking/s...ge%20indicator

One thing for sure, coming from HobbyKing, you can count on this unit being extremely accurate ...

I purchase ONLY HobbyKing airplanes,radios,rx's,batteries,servo's,switches etc... they seem to fly really good but for some reason they always crash after a couple of flights.