Opto kill switch with BEC
 

I ran a search and got lots of varying information. I have the RCexel Opto kill switch with BEC (from VV RC last fall) and it does NOT seem to be cutting the 6.6 input voltage down to 6V or less at all. (still reading 6.6 or so) My XYZ ignition (RC Exel) says 4.8 - 6.0V right on it. I think I paid extra getting the BEC version of this Opto kill switch that is supposed to cut the voltage down. Is there any chance that when I actually hook it up to the ignition unit that it will magically reduce the voltage to 6V or less, or do I need to get a regulator/diode on top of having this BEC unit? Thanks a bunch!

RE: Opto kill switch with BEC
 

Tech-Aero Ultra IBEC at BP Hobbies (US$ 40.00)

RE: Opto kill switch with BEC
 

RCexl discontinued that BEC version of the opto-kill switch like three or four years ago. None of the current RCexl Opto switches have a BEC in them. It isn't shown on the RCexl website either.  So I seriously doubt that you  have a BEC inside your RCexl Opto-kill switch.

I would use either a voltage regulator in series with the ignition power wires on the opto-kill switch or run a 4.8 volt battery pack for it,  I am actually using a Castle Creations voltage regulator with a LiPo pack in one plane with the RCexl opto switch. In a couple of other planes I use the Tech Aero combination BEC and opto kill switch and it works well too.

http://static.rcgroups.net/forums/at...ch_large03.jpg

RE: Opto kill switch with BEC
 

Hi Ernie!

VV sells the RCEXL switch 3 ways. The first is stock (19.95), w/the 4th lead going to your battery/power source. The second switch has been modified internally (very easily done yourself BTW, if you can solder?) to use power from the lead that also controls the switching function (29.95). 4th lead removed. The third, is the second switch modified to drop/regulate the voltage (34.95).

Either of the second 2 could be said as having a BEC? I would suspect your hunch about needing a load placed on it while measuring output it is spot on.

I suspected Valley View was modifying the stock switches in house, but now I see them available elswhere? So now I wonder if Rcexl has started offering the different versions, or if others have decided to mod the stock switch in house as well? Anyone know for sure? -Al

Edit: I've been using home modified (per directions supplied with the switches) switches since they came out with the newer version in the hard case (vs. the original supplied in shrink wrap). They work exactly as they should. Myself and others I know are using them without a single failure.

RE: Opto kill switch with BEC
 

If interested in doing the unregulated "BEC" thing, the PDF is the document that comes with the switches. If you go to the bottom of it you can see the mod clearly illustrated in a couple of pics. It consists of 2 small dabs of solder. If you have a 6v ignition and want to run LiFe or 5 cell NiMh, you can add a 50 cent Radio shack diode to the positive lead. If you have a newer 8.4v ignition, you'd be good to go without the diode.

Not promoting the practice, but some are saying they're running 6v modules on LiFe without the diode, and having pretty good luck. FYI....

RE: Opto kill switch with BEC
 

Thumbs up for the Tech Aero IBEC. All of my gas planes have them. Tech Aero Voltage regulators also. These are terrific products that work every time, exactly as they are supposed to...

Having had a small hand in it's development I know how good the IBEC isandI am still using the original prototype IBEC from 4 years ago......The current product is even safer with improvements to the RFI filtering and much brighter LED. Highly recommend these

RE: Opto kill switch with BEC
 

Same here for the Tech-Aero IBEC. And MTK's fuel line.

RE: Opto kill switch with BEC
 

Al, my RC Exel opto switch with BEC says type K1, Ver 2.0, for A-123. It has only 2 wires (in and out) plus a LED bulb wire. There is another "input" with no wire plugged into it.... would take a very small plug. I'm sure Tom at VV says this was supposed to cut down the voltage without any mods or anything but this was last fall. I will give him a call today. Thank you for your info on the mods as well.

The Tech Aero IBEC looks terriffic. So doe the Flightmaster that Tower sells for $10 more I think.

RE: Opto kill switch with BEC
 

Ernie,
Maybe you could ask him if those that are BEC equipped are purchased directly from Rcexl, are modified in house, or maybe by a 3rd party? Doesn't make a hill of beans difference, just curious.

Matt,
Clearly the TechAero swithes are popular and work well. By now though, it should also be clear many think the same of the RCexl product? As these are the same people making the lion's share of the ignitions in use today, they're reputation shouldn't even be in question?

Inserting the fact you think highly of your Ford product into a Chev. conversation may not be the most relevant comment? Just sayin....

RE: Opto kill switch with BEC
 

Thanks Al, I'll see what I can find out. PS - my RC Exel Opto with BEC is a newer type with a little metal box, not the shrink wrap version. If it doesn't reduce the voltage why put the BEC on it? I'm not inclined to take it apart and solder, although I could. What the heck is supposed to plug into that extra input (would require one of those tiny plugs) that says 20V DC Max?

RE: Opto kill switch with BEC
 

The "extra" input would normally be plugged into a battery. That's the 4th connection I was talking about? It's no longer necessary if you're getting power from the "control" connection, the one that's pluggged into the receiver that's used to turn the switch on and off?

The reason it's markd <20v is because it's able to switch devices other than ign. modules? Stuff that may be set up to run on higher voltage.

The newer ign. modules are rated for up to 8.4v. They would not need a voltage limiting circuit as part of a BEC. It's why VV is selling them both ways. -Al

RE: Opto kill switch with BEC
 

Tech-Aero all the way. Best $40 bucks you will spend on this type of device. I use one on every gasser I own.

I picked up a bird that seems to have one of these on it, but the Velcro was attached in such a manner that I can barely make out that it says "K-1 and V 2.0" I assume it is what is being discussed here. The back side has a date of 2012.

The questions I have is where to plug it in on my radio (assume a 7 channel RX - though I could go for 8 if that is really really needed) and how do I test it for a voltage drop? Do I need to? The bird has a DL 50 on the nose and that suggests it can handle up to the 8 volts most A123 systems put out. Or am I all wet?

Not wet I don't think?

Many with computer radios will plug that lead into the receiver anywhere and assign it a switch? Others, possibly with older radios, will set it up just like they would for landing gear, using an aux. outlet on the receiver and transmitter switch normally used for landing gear? Either way, make sure you set the transmitter up so that channel gets full travel!

You're also right in that there's no reason to be concerned about dropping voltage to an ign. module rated for 8v.

Thanks!

I figured out the retract switch is the only place on my 7 channel RX because all aux channels are in used - dual elevator and aileron servos - and I am to lazy (or is it cheap?) to break out the 8 channel RX. So much fun! With most retracts, I use the brush up to confirm gear down and locked but for this bird, I think it will be 'ignition on and hot'. At least the LED will help me keep track.

I have both the RCExl and the Tech aero and both work without a problem . The upside to me on the Tech aero is that you can select your ignition voltage making it easily adaptable to any ignition input voltage requirement.

In regards to the opto gas engine kill switch V 2.0 I am talking about the opto with only two wires and one LED older ignition modules only required 6 volts the new ones can take higher voltage up to 8 volts there is no longer a need for a second battery the two wire kill switch simply plugs into the receiver and into the ignition module that all you have to do. I received this information directly from Valley View RC

I will add a safety note. Years ago when "Giant Scale" started, it was decided that an engine cutoff switch should be on the outside of the airplane for emergency use. In our new high tech world I see no evidence that this is still not a good idea.

So I wire a switch in the power feed (clearly marked and positioned near the engine) to the ignition always!

IMHO

For clarity to those not familiar, Valley View sells the Rcexl opti switch, w/BEC mod done for you, at a slight additional charge over what the standard switch goes for. To my knowledge, they're the only one providing that service. -Al

Agreed!

Yes this is a great idea in fact I put a manual switch from the receiver to the ignition module for redundancy it can damage your ignition if you accidentally leave your radio switch on everytime I walk to my plane I shut off the radio switch and the manual switch

I like to use Billet aluminum twin switch from Valley View RC this enables me to switch from Battery to RX and the other switch RX to ignition module these units are high and tight and look really nice on your aircraft