[3daviator]

Hey Guys,

Anyone powering their ignition off the RX?

I'm setting up a 35% with a DA-100, JR 1222, 2x A123 2300's on RX. I have a smart-fly opti kill and would run it off a spare rx channel or run a seperate A123 2300 (6oz).

I'm running my 50cc (DA) Yak off one A123 2300,it has two JR leads, one for charging and one for the ign/smart-fly, + deans to the 922rx. Not a lot of time on it but runs great, no problems.

[rrembert]

I'm running the ignition off of the receiver batteries on two of my planes...using the JR charge lead into the kill switch. So far it has worked flawlessly..

[Tired Old Man]

A lot of people are doing this but they forget one thing. It only takes once. There is no greater source of EMI in your plane aside from the ignition. If it gets through, your plane is through. Consider some type of separation or buffer if you intend to run an ignition of through the receiver. 2.4 is not immune to EMI.

[Buttface]

Not me ...I want to make sure I can still control my motor if the ignition fails!.........Uh nevermind.(just being stupid)

I am a firm believer in keeping the ignition TOTALLY separate from the rx....You should listen to Tired old man, hes been around a loooooooong time and knows the ropes. I have proof of this.... Running 2.4 my ignition failed (separate from the rx) and it picked up on all the nose the failing ignition was making causing it to go into full lock out on and off ...luckly I was able to line it up for a smooth full lock out landing!!!! (could have played out different if the ignition was connected to the rx) if you know what I mean.
I always use a servo to manually close the choke for a cut off....yea I know a 7950 is overkill !HA!

[Mithrandir]

I thought a battery was a pretty good filter???

or maybe add a Cap in the circuit??

[Buttface]

Originally Posted by Mithrandir

I thought a battery was a pretty good filter???

or maybe add a Cap in the circuit??

Or run the ignition on its own dedicated receiver and a 5 cell lipo regulated down to 6v ....on a separate transmitter (a spare 14mz will do)

[Tired Old Man]

A battery by itself is an excellent filter, but can it be depended on to effectively filter out 15Kv-18Kv of EMI? That's a question I don't want to be the first to find out, especially when there is no assurance that EMI will go to (through?) the battery first.

Is the cost of a $3,000.00-$6,000.00 plane a fair trade off for 7 ounces of weight, one switch, and 1, 4.8v battery with a total cost of $35.00?

Each will have to make their own decision.

[Wallygator]

I'm using two A123's for RX power through a Fromeco Wolverine switch with three outputs. The third output feeds a Smartfly sport regulator that is feeding 5.0V to the RCExcel ignition cutoff. Works perfect on my 2.4 Aurora, 72mhz it might not be as stable.

[terickson]

The whole point of the opti-kill is to isolate ign from rx. I use a 900 mah lipo thru a Castle 10a BEC to power the ignition. 2.5 oz worth of insurance.

[wildhare]

I have done what you are asking about in every plane I own for almost 3 years. I've done it with every brand name 2.4 radio on the market; JR/Spektrum, Futaba FASST, Airtronics FHSS, Hitec AFHSS, and several types of receiver in each brand.

I don't use anything to isolate the ignition, I just take power from the charge/balance lead of my A123 battery and route that through a mechanical switch.

This has always worked perfectly for me and know that many of my customers have used this arrangement. I like it because of the simplicity and reliability.

Here's the way I look at it. In 3 years I've never had a dead stick due to a bad ignition battery, because I am not able to forget to charge the ignition battery. I am quite certain that some time in those 3 years having a separate battery would have caused some kind of a problem, so I figure I'm already way ahead of where I would have been.

If I have a plane that has dual (redundant) batteries I still pull ignition power from one of them.

I never pull power from any electronic component, just direct from the battery. I don't know if this matters but what works for me is solid and when I find a working combination I stick with it until there is some reason to change.

Putting an opto-isolator cutoff in the circuit would seem to protect against the day when an ignition fails internally and starts feeding high voltage back through the power lines, I may start doing it that way. The opto-isolators are cheap but do add to the number of things that can go wrong. Maybe someday I'll use one, but right now I don't see even the need for that.

You should do what you are comfortable with. But every post that I have seen from anybody that is actually doing it this way has said it works fine just as mine do.

TF