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Wig Wag Choice and Current In-Rush Limiters

gmcjetpilot

gmcjetpilot

Well Known Member
I am sporting two single FLYLED spotlights in each wing tip... Current draw is low compared to Halogen, about 1.25 amps (steady state)

Two things:

1) What is the recommended Wig Wag switch/device and experience?
(FlyLED, CRAZEDpilot, Perihelion Design, Crew Dog, Automotive, DIY Roll Your Own)

2) Current In-Rush Limiter (small solid state component to avoid current spikes), I thought wouldn't be needed, but read yes, good idea, LED's can have big inrush currents as well? Thoughts?
If current limiter is recommended what part number. Only one Wig Wag includes in rush limiters. It is like fly-back diodes on relays. Can do without but help increase switch life. Some WigWag circuits may include current limiting?
 
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I used a turn signal flasher. You want the electronic type, not the old thermal type (not sure you can even find those any more).
So, yes, my lights blink on/off in sync, not wig/wag. But is was $20. instead of $100 or more.
My landing lights are LED. This wouldn't work with high current lamps.

By adding a SPDT relay after the flasher (maybe another $10), you can roll your own wig-wag for $30.

$20 saved here and there adds up!
 
Since you are using the FlyLed landing lights, there is no need to worry about inrush current limiting. These lights use a series dropping resistor (which will limit the current) instead of a pulsed power supply. That’s also why they don’t generate stray noise. I have the ‘works’ and it all works fine, but I have not actually tested the wig-wag (this was a retro-fit installation using pre-existing wiring). I do wonder: how much more attention getting is the wig-wag compared to just landing lights ‘on’?
 
I currently use the 'WAT' (Whelen) model #7170001 after my previous flasher gave up (small red one).
I run Aeroled 45W sunspots. The Whelen can handle 10amps (140w) if I decide to run the 75 or 100W lamps down the road.
 
I currently use the Perihelion switch in my 7 with LED lights and no current limiter. I have run them all flight (don't fly at night) long for the 750 hrs on the plane so far. No issues. I have installed the Fly LEDs landing/taxi lights on my 8 under construction and am using their wigwag module. They will be turned on wigwag every flight as well. Not expecting any issues with this system either.
 
BobTurner said:
... I do wonder: how much more attention getting is the wig-wag compared to just landing lights ‘on’?
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Empirically measured, but it's the key to being seen!
A bright light is great but it's easily missed or even masked by other light sources. The apparent movement of the light from side to side is the eye catching part.
Trains commonly run wigwag lights now too. And there's a reason why there's two red lights wigwagging at every railroad crossing, rather than just a simple stop light...

Our The Works kit will wigwag the landing lights, and we have two different products that suit all panels and every plane.
 
It sounds like the FlyLeds have something already built-in to limit the initial current. I have a Perihelion wig wag switch and I had one go bad on me using LED landing lights. I always have my wigwags On. Eric from Perihelion said thermistors should be used. The person who installed the landing lights didn’t use thermistors. Thermistors limit the current when you initially turn On the lights and as the thermistors warm up it allows more current to flow. Thermistors are fairly cheap

To clarify: Eric said to use thermistors with his wigwag switch.
 
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FireMedic_2009 said:
It sounds like the FlyLeds have something already built-in to limit the initial current.
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Flyleds lights just ramp up from 0 to 100% current and the feedback mechanism just puts the brakes on (or lifts the foot off if you'd like) at about the 98% mark. There's nothing on board to charge up so there's no overshoot or surge current.

Other brand LED lights may have a power supply in them that would need an initial boost up but I can't speak for those. Ask the manufacturers! I'm guessing that if they thought it was an issue with their products they'd include them.

Conventional/old school filament lamps can have a much lower resistance when they are cold in comparison to when they are operating, so that is the only reason I can think of to use inrush limiting, especially on an expensive high powered lamps. In some applications (like the (RV related...) railroad crossing lights mentioned above) they would feed the lights with an extra current source that would keep the filament warm but just below visible for this reason.
 
Paul from Flyleds said:
Empirically measured, but it's the key to being seen!
A bright light is great but it's easily missed or even masked by other light sources. The apparent movement of the light from side to side is the eye catching part.
Trains commonly run wigwag lights now too. And there's a reason why there's two red lights wigwagging at every railroad crossing, rather than just a simple stop light...

Our The Works kit will wigwag the landing lights, and we have two different products that suit all panels and every plane.
Click to expand...
Hi Paul, I've thought some more about my own question. I think it has to do with the human brain and peripheral vision in humans. My brain tends to ignore things in my peripheral vision that are steady, but is alerted to things off to the side that are moving (or blinking, like the wig wag lights). So the wig wag does not help much with airplanes that I am looking directly at, but wig-wagging does draw my attention to airplanes that are off to the side of my central line of sight. That's my theory. Maybe I'll take the time next annual to run some wires to the wig wag circuit.
 
Thirty years ago, I purchased a $7.77 J.C. Whitney Emergency Vehicle headlight Wig Wag flasher. It was disassembled and the flasher adapted to Wig Wag flash my two 100W RMD wingtip landing lights. It has worked great. I upgraded to cheap Amazon LED replacement bulbs that draw a lot less current (1.25 Amps) eight or nine years ago. Had to design a filter to get the noise from the cheap LED bulbs out of the radios. Wig Wag still works when the engine is running but battery power alone appears to drop the voltage just enough that the Wig Wags will not flash when the alternator is off line.

My RV-8 project will have FlyLeds. They are already purchased, fabricated, and installed in the wingtips.
 
I originally had the FlyLed wigwag switch installed on my RV7A while my plane was down for prop strike insp and repair by Myer Aviation at OSH. My landing lights then were Whelen LED. Meyers even made a real nice new switch cover when they did the installation. Wasn’t that expensive and they did a real professional job.

After I got the aircraft home I loved the FlyLed switch so much I went ahead and upgraded to the Works system doing that installation work myself. It wasn’t difficult. The advantage I see of wigwag lights is that traffic can spot my aircraft much easier therefore enhancing their ability to “see and avoid” me. I just wish the traffic I’m looking for also had wigwag lighting so I could see and avoid them easier. The Works package has strobe, position and great landing/taxi lights. When everything is turn on I light up the sky - day or night!
 
The FlyLeds lamps use a constant-current driver (about 1.1 amps for each lamp). This prevents any radiated electromagnetic noise, and allows for simple wiring. The only downside of this circuit is that below about 11 volts, the lamp brightness declines. Not a problem in normal operation.

The circuit is quite simple (as I recall), with two transistors and two resistors, so is very reliable.
 
Thanks everyone. I feel better. :) Great info and I learned a lot (the whole point of building an airplane).

Not that I needed to, but wanted to see if and how I could measure in-rush currents for different loads. I verified from my crude testing FlyLED has no in-rush current I could measure, as expected. I tried ammeter wired in series, and I tried clamp on DC ammeter. Both ammeters have max/min capture. These are not fast enough to measure a peak even if there was a peak, but I tried. Then tried trusty oscilloscope and a shunt, shunt nothing. Yes the electronics lab also doubles as a kitchen. Ha ha. Work bench full and fabrication shop, also known as garage, was cold.

Thanks a million for all the comments.

light inrush test2.jpg
 
I read that flying with the landing lights on reduces the risk of bird strike by 30%. I'd think wigwag increases that percentage a bit, as I sure can see them better when they're flashing. Perhaps birds can too. Unfortunately those da*n deer on the runway didn't seem to care at all, but my Advanced ACM stops the flashing at 60kn for landing... Mine stay on all the time while flying.
 
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