# DIY LED Afterburner HELP!

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**1**Member

Thread Starter

Join Date: Jul 2011

Posts: 38

**DIY LED Afterburner HELP!**

Not sure if this is the right thread for this but here it goes...

Looking to make a led afterburner on one of my planes. I want the led brightness to coincide with the throttle. I know that one way to do it is to connect the led's to a low amp brushed esc inline with the brushless esc then connect both esc's to the throttle channel via Y-harness and voila.

I'm looking to skip the whole extra low amp brushed esc. Would I be able to just connect the led strip to an open channel on my rx and mix it in with the throttle? Or would the voltage be incorrect? Any help is greatly appreciated.

Looking to make a led afterburner on one of my planes. I want the led brightness to coincide with the throttle. I know that one way to do it is to connect the led's to a low amp brushed esc inline with the brushless esc then connect both esc's to the throttle channel via Y-harness and voila.

I'm looking to skip the whole extra low amp brushed esc. Would I be able to just connect the led strip to an open channel on my rx and mix it in with the throttle? Or would the voltage be incorrect? Any help is greatly appreciated.

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**2**Looking to make a led afterburner on one of my planes. I want the led brightness to coincide with the throttle. I know that one way to do it is to connect the led's to a low amp brushed esc inline with the brushless esc then connect both esc's to the throttle channel via Y-harness and voila.

I'm looking to skip the whole extra low amp brushed esc. Would I be able to just connect the led strip to an open channel on my rx and mix it in with the throttle? Or would the voltage be incorrect? Any help is greatly appreciated.

I'm looking to skip the whole extra low amp brushed esc. Would I be able to just connect the led strip to an open channel on my rx and mix it in with the throttle? Or would the voltage be incorrect? Any help is greatly appreciated.

The rx only gives a PWM signal with short pulses differing a bit in length and with no power at all. In any case you need some kind of electronics. And a brushed ESC should be quite cheap nowadays (ebay...).

RK

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**3**Member

Thread Starter

Join Date: Jul 2011

Posts: 38

Now my question is this. I will be running 4s batteries so how do I attach a voltage regulator to the led strip? What kind of voltage regulator would I need?

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**4**Past President of PSSF

Join Date: Sep 2009

Location: Lacey WA, 1 mile E of Mushroom Corner

Posts: 1,990

Here's what I use.

I have a string of Leds controlled by a Castle Creations, Pixie-7P with the red wire cut to disable the BEC.

It can handle 7 amps and up to 21Volts with red wire cut, but you will need to put a resistor in series with your leds to drop the voltage down to something they can handle without burning up.

Ohm's law can help you figure the value for the resistor.

My led strip pulls 400 ma at 12 volts. If I want to run it from a 4s pack, I am going to assume the pack is putting out about 16 volts. (at full charge it would be 4 x 4.2 = 16.8) That means I am 4 volts too high. I need to find a resistor that will have a 4 volt drop across it at 400 ma.

In electronics, E represents Voltage, I represents Amperage, R represents Resistance

(all in full units)

Ohm's law is

volts equals -- amps times resistance -- or E = I x R

Amps equals -- voltage divided by resistance -- or I = E/R

Resistance equals -- voltage divided by amps -- or R = E/I

So in my example to find the resistor, I will use the amount of voltage I need to drop (sort of get rid of) which is 4 volts,

and the current the leds pull when operating at the voltage they are designed for, in my case 400 ma,

since 1 ma means 1/1000 of 1 amp, 400 ma = 0.400 amps

Put all this into the formula and it is --- 4 / 0.4 = 10 ohms

So I would put a 10 ohm resistor in series with the leds, and then I could run them from 16 volts without burning up.

Since watts equals I x E in my example I will also lose 0.4 x 4 = 1.6 watts, not enough to bother with a fancy voltage reg.

Hope this helps

If I knew the voltage your leds require, and the total current at that voltage, I can figure the resistor for you.

I have a string of Leds controlled by a Castle Creations, Pixie-7P with the red wire cut to disable the BEC.

It can handle 7 amps and up to 21Volts with red wire cut, but you will need to put a resistor in series with your leds to drop the voltage down to something they can handle without burning up.

Ohm's law can help you figure the value for the resistor.

My led strip pulls 400 ma at 12 volts. If I want to run it from a 4s pack, I am going to assume the pack is putting out about 16 volts. (at full charge it would be 4 x 4.2 = 16.8) That means I am 4 volts too high. I need to find a resistor that will have a 4 volt drop across it at 400 ma.

In electronics, E represents Voltage, I represents Amperage, R represents Resistance

(all in full units)

Ohm's law is

volts equals -- amps times resistance -- or E = I x R

Amps equals -- voltage divided by resistance -- or I = E/R

Resistance equals -- voltage divided by amps -- or R = E/I

So in my example to find the resistor, I will use the amount of voltage I need to drop (sort of get rid of) which is 4 volts,

and the current the leds pull when operating at the voltage they are designed for, in my case 400 ma,

since 1 ma means 1/1000 of 1 amp, 400 ma = 0.400 amps

Put all this into the formula and it is --- 4 / 0.4 = 10 ohms

So I would put a 10 ohm resistor in series with the leds, and then I could run them from 16 volts without burning up.

Since watts equals I x E in my example I will also lose 0.4 x 4 = 1.6 watts, not enough to bother with a fancy voltage reg.

Hope this helps

If I knew the voltage your leds require, and the total current at that voltage, I can figure the resistor for you.

#

**5**Member

Thread Starter

Join Date: Jul 2011

Posts: 38

I have a string of Leds controlled by a Castle Creations, Pixie-7P with the red wire cut to disable the BEC.

It can handle 7 amps and up to 21Volts with red wire cut, but you will need to put a resistor in series with your leds to drop the voltage down to something they can handle without burning up.

Ohm's law can help you figure the value for the resistor.

My led strip pulls 400 ma at 12 volts. If I want to run it from a 4s pack, I am going to assume the pack is putting out about 16 volts. (at full charge it would be 4 x 4.2 = 16.8) That means I am 4 volts too high. I need to find a resistor that will have a 4 volt drop across it at 400 ma.

In electronics, E represents Voltage, I represents Amperage, R represents Resistance

(all in full units)

Ohm's law is

volts equals -- amps times resistance -- or E = I x R

Amps equals -- voltage divided by resistance -- or I = E/R

Resistance equals -- voltage divided by amps -- or R = E/I

So in my example to find the resistor, I will use the amount of voltage I need to drop (sort of get rid of) which is 4 volts,

and the current the leds pull when operating at the voltage they are designed for, in my case 400 ma,

since 1 ma means 1/1000 of 1 amp, 400 ma = 0.400 amps

Put all this into the formula and it is --- 4 / 0.4 = 10 ohms

So I would put a 10 ohm resistor in series with the leds, and then I could run them from 16 volts without burning up.

Since watts equals I x E in my example I will also lose 0.4 x 4 = 1.6 watts, not enough to bother with a fancy voltage reg.

Hope this helps

If I knew the voltage your leds require, and the total current at that voltage, I can figure the resistor for you.

Purchased this from eBay. Not much info on it. Any recommendations?

http://www.ebay.com/itm/180687140964...ht_3493wt_1163

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**6**Typical BECs don't give you 12V.

RK

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**7**Past President of PSSF

Join Date: Sep 2009

Location: Lacey WA, 1 mile E of Mushroom Corner

Posts: 1,990

Pulling the 12v or 3s on the balancer cable will work just fine. It's simpler than a resistor, just watch the balance of the battery, because you will be discharging some cells a tiny bit faster than others, if the leds are wired correctly. I have seen some suggested wiring diagrams that would pull much more current than necessary.

If you don't have a good digital meter to read volts, amps & resistance, I would highly recommend getting one, also a inline wattmeter is almost necessary when setting up a good flying plane, it will help you choose the right prop, without burning up the motor.

Good luck if you need more help, we are here.

The basic electricity lesson I posted first, may come in very handy, when you can't tap into the battery's balance plug. I do some custom work with just bare leds. Some need very different voltages and currents, than others, so I just gave you what I do all the time, didn't mean to bury you in tech talk.

If you don't have a good digital meter to read volts, amps & resistance, I would highly recommend getting one, also a inline wattmeter is almost necessary when setting up a good flying plane, it will help you choose the right prop, without burning up the motor.

Good luck if you need more help, we are here.

The basic electricity lesson I posted first, may come in very handy, when you can't tap into the battery's balance plug. I do some custom work with just bare leds. Some need very different voltages and currents, than others, so I just gave you what I do all the time, didn't mean to bury you in tech talk.

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**8**Member

Join Date: Apr 2013

Location: Maine

Posts: 195

I hope this reaches someone as the post is old. I am looking to get an afterburner kit but it runs straight off the receiver leads to the battery. Why would this not be ok ? Does anyone have one or been using one ? Found it on Ebay. I cannot find a 70mm one that plugs into the balance plug of my 6cell. Can anyone point me in the right direction. I want to do it right. Thanks !

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**10**Member

Join Date: Apr 2013

Location: Maine

Posts: 195

Panther,

Thanks for the reply. I actually was thinking about that one. But some of the reviews caution about how to wire it up. Also does not hook into the balance plug but directly to the battery. I have read that is not as good. Confusing because it is made to be wired into the planes system as described.

Thanks for the reply. I actually was thinking about that one. But some of the reviews caution about how to wire it up. Also does not hook into the balance plug but directly to the battery. I have read that is not as good. Confusing because it is made to be wired into the planes system as described.

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**12**Member

Join Date: Apr 2013

Location: Maine

Posts: 195

**Does anyone have this afterburner ?**

I was thinking on getting one http://hobbyking.com/en_us/dr-madthr...___store=en_us

But I was hoping somebody has some experience with it ? Seems like just what I'm looking for.

But I was hoping somebody has some experience with it ? Seems like just what I'm looking for.

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**13**
Have you tried or thought about this I did it in the past and it came pretty good.

https://www.flitetest.com/articles/f...d-afterburners

https://www.flitetest.com/articles/f...d-afterburners

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