RE: opto kill switch
 

Paul

"OPTICAL" KILL SWITCHES EXPOSED!

Check this out! Wires to the ignition module on one side. Wires to your receiver on the other. Connecting them, components and copper circuitry. Isolation, none. The result, coupling from your ignition module right into your receiver. This isn’t the type of kill switch you want to use. Dan.

RE: opto kill switch
 

Jeez, sorry to upset you!
Just trying to give another option, particularly for those of us who live on the other side of the planet.

RE: opto kill switch
 

My apologies. Not upset any more. It really was redirecting me to a garbage site. Now it is working. Must have been a name server erro or corrupted. All is fine. I see what you were pointing to now.

RE: opto kill switch
 

No worries mate.

RE: opto kill switch
 

Both these devices use an Opto Coupler/isolator to provide the isolation between the power side and the rx side

ie all done inside a component on the board, some info on opto couplers in below link.

http://en.wikipedia.org/wiki/Opto-isolator

Scott

RE: opto kill switch
 

Scott thanks for that website. Boy, was that a long description of the optical switches. They do isolate the connections from the passage of electrons from one side to another. This is called conduction. However, that is only one half of the threat to a receiver. The other half is radiation. I have attached a schematic of an ignition module. If you are not familiar with schematics, here’s a few sentence explanation. The lines represent wires or copper traces and the illustrations components. At the left side is the Hall sensor or pickup that is on your crankcase. It overhangs the prop hub that has a magnet in it. When the magnet passes by the sensor, it sends a signal that generates the high voltage that causes the spark. The spark plug is on the right side. The spark can contain radio frequency components that fall within the range that our radios work on, 2.4GigaHertz. Those components are what is called radio frequency interference, or RFI. They radiate out as an electro magnetic field just like the signal from your transmitter radiates out from its antenna. In the middle of the schematic on the bottom, you can see the “GND” terminal. That is the black wire from the ignition battery. Above that is the “Power +4.8-6V” terminal. That is the red wire from the battery. The RFI from the spark couples directly in to the ignition battery, or in this case, the kill switch with ease. The trouble with this kind of kill switch is that it is useless to stop the RFI and it couples right in to your receiver. It is easy to suppose that since a lot of guys are using these, the switches are all right. Not so. One of beauties of the 2.4 systems is that we can fly right through the interference from or fellow modelers but also through the interference that we generate in our own flight packs. So what’s wrong with that? you may ask. Plenty! You consume what is known as margin. Margin is that extra amount of a performance factor you need to make sure that you can fly safely regardless of the surrounding interference. It’s a precious value. The less margin, the more likely the system will fail. The best kill switch around is the Smart-Fly one. That optical line provides conductive and radiated isolation. Dan.

RE: opto kill switch
 

Double post. Dan.

RE: opto kill switch
 

Given the number in use, and the problems encountered, I would say the information you're trying to propagate is inaccurate.

That's just a guess though since I'm no expert ;-)

RE: opto kill switch
 

I'm with you. Despite the fact so many of us have been using these for years now, without incident, there are still those that insist they don't work, refusing to acknowledge what seems like pretty solid evidence to the contrary.

RE: opto kill switch
 

Futaba's suspitions of the optical kill switches has been aroused since they have added them to their advice posted on their website along with the infamous metal throttle pushrod. Dan.

Guidelines for setting up gasoline engine models.
All ignition equipment, including an electronic kill switch, must be mounted at least 12", and preferably 14", away from all radio equipment, including throttle servos, etc. Ignition kill switch should always be on opposite side of fuselage from radio kill switch. All pushrods going to anything related to the engine must be non-conductive (just nonmetal clevises is not sufficient).

RE: opto kill switch
 

Yes yes, and they wrote those while listening to Lawrence Welk on their 8 tracks :D

RE: opto kill switch
 

+1 :D

I think someone is just trying to justify one costing close to three time the cost of a RCexl.

I have probably sold over 300 of the RCexl in the last three years and have not had one complaint about them.

Milton

RE: opto kill switch
 

I'm afraid I will have to throw in with Dan on this one. The pictures in Dan's post show very little protection from RF interference. The ignition circuitry is electrically isolated from the receiver circuitry but the RFI is still a factor. I believe the reason so many are successfully using these units is the excellent shielding in the modern CDI units and the inherent ability of the modern spread spectrum receivers to reject interference. Just my opinion...........RJ

RE: opto kill switch
 

Welk sounds so much better on vinyl!

RE: opto kill switch
 

Milton, a questiona little off subject....

What is the benefit, if any, between the ICM6 iridium plug and the CM6 from NGK?

Was using the stockDLE plug in my 55 and had slight backfiring at idle. Switched to CM6 last night and backfiring seemed to have stopped. Will the iridium plug help improve running any further considering slight richness at the bottom?

thanks

RE: opto kill switch
 

LOL Weren't you the one that said you never had a problem with those stock plugs just a few days ago? :D


We had an EME doing the same thing with a stock plug, stuck a CM6 in and it ran like a top.

Chinese stock plugs are junk.

RE: opto kill switch
 

Yes, so what?? The stock DLE plug worked well enough to break the engine in, some 10 gallons through it by now. It never backfired before. The engine was laid up the past 2 years waiting the completion of my new project. Now that it's back in service, engine was backfiring ever so slightly so it might have been the plug, so plug's been replaced

What compels people to make stupid comments is beyond me. Just want to hear themselves talk I suppose<br type="_moz" />

RE: opto kill switch
 

I have a question for you too Milton. I've seen Rcexl switches in a couple different places now that use the lead that plugs into the receiver to supply power to the ign. module, rather than having a seperate power lead. Are these switches coming from Rcexl this way, or are people modifying them per the directions that come with them, and selling them this way for a couple bucks more? -Al

RE: opto kill switch
 

The only benefit that I know of comes from customer feed back that say they get a better idle with it, other than that none at all as I know of.

Milton

RE: opto kill switch
 

Edit

I though you were talking about just there regular power switch.

They will work that way without any modifications, I just do not like doing it like that but to each his own.


Milton

RE: opto kill switch
 

Thanks Milton. I'll wait

RE: opto kill switch
 

The smart fly uses a transmitter and a receiver connected by piece of fiber optic cable. works great, However it is a common practice in the world of electronics to isolate optically on one small board. You don' t have to separate the transmitter element and the receiver with a long piece of cable. I have both types in use right now both types work as they should.

RE: opto kill switch
 

I have been useing 3 rcexel kill switches for over 3 years, no problems with Futaba 2.4 radio.
All I know is they work.
There seem to be people who say they shouldn't work, but no-one who actually has one that doesn't work.

RE: opto kill switch
 

Maybe I'm confused? Is there more than one version of the Rcexl Opti Switch available?

RE: opto kill switch
 

Maybe I'm confused? Is there more than one version of the Rcexl Opti Switch available? -Al