I am having the strangest issue with my external Smart fly ignition kill switch. In my 36% PAU Edge 540T I am running dual A123's feeding my Smart fly Power Expander. For strange reasons, I have an external Smart fly ignition kill in this aircraft. I plug the ignition kill into the Power Expander. With the Futaba 6014-HS, everything works great initially. The 14mz radio switch easily turns the ignition kill off and on.

Now, with the DA 120 running, especially at top RPM, the LED on the ignition kill transmitter goes out for about a second, then comes back on. The ignition kill receiver LED also goes out and kills the DA ignition.

I plugged a servo into the same Power Expander output port as the ignition kill to see if a signal was being sent to the ignition kill transmitter, and the servo never moved. If I hit the kill switch on the 14mz, then the servo moves and the ignition kill LED goes out.

So, everything seems to be working correctly, but at high RPM the ignition kill will cut off the ignition for about a second randomly. What is going on here?

I replaced the ignition kill transmitter with a new one from Smart Fly, and the same thing happens.

Finally, I unplugged the ignition kill transmitter from the Power Expander and plugged in directly into the 6014-HS receiver. With this final setup, no more random ignition kills. Everything works very well and is reliable.

Could this issue possibly be due to the A123's voltage and resolved by using the 5 volt regulated voltage to the 6014-HS?

I think i can solve that one for you! I have almost the same set in my extra 330sc with the smart fly system only with lithiums instead of the 123 and it was doing the same thing in flight at high rpm, Engine would cut out for just a sec and found that i was in fact the ignition kill was the culprit. Running it on the ground i find the same issue as you with the led, on and off for just a sec. Solution was a totally separate ignition battery! Even talked to smart-fly directly and was told the same thing that their power systems do not and i repeat do not have a IBEC circuit within it.

Many thanks for the response. However, I am running a separate ignition battery. I could see where using the same battery would cause an issue like this.

It turns out that my issue was due to the receiver channel being set to high speed servo mode. When I switched to a channel that was not set for high speed, then the issue cleared.

As far as I can tell, this was the issue. I would like to get rritchy's input on this. But, for now, I would suggest that everyone avoid high speed servo channels for these ignition kill switches.

Hi,
The way I remember the code is setup it should not matter if the servo setting is high or normal speed but I need to go back check to see if I have anything in there that would cause an issue updating at 7.5msec instead of 15msec. These units were designed before anyone was running servo updates faster than 12msec. Thanks for the input.

Originally Posted by jkhorvath

Many thanks for the response. However, I am running a separate ignition battery. I could see where using the same battery would cause an issue like this.

It turns out that my issue was due to the receiver channel being set to high speed servo mode. When I switched to a channel that was not set for high speed, then the issue cleared.

As far as I can tell, this was the issue. I would like to get rritchy's input on this. But, for now, I would suggest that everyone avoid high speed servo channels for these ignition kill switches.