In search of new WIG-WAG flasher

[dan]

Originally Posted by Jim Percy

Just curious about what made it a "painful" death. Are you referring simply to the pain your wallet felt? I've got the same flasher unit installed in my airplane.

Instead of click-clack-click-clack, now it goes "Waaaaaaaaaaaaahhhhhhh!" Sounds painful to me.

[dan]

I bought a Tridon EL13A-2 from Midway Auto Supply and will try that.

[vlittle]

The so-called 'solid state' flashers that you buy from automotive sources is an example of misleading advertising.

In fact, they are electromechanical devices (relays) with a transistor oscillator in them. What wears out are the relay contacts.

I designed a true electronic flasher some time ago, but didn't take it to market because of the price (had to be at least $50), and I thought that there might be a better way.

The better way (which has not been exhaustively proven yet), is to put NTC thermistors in series with the lamps. These are readily available, and have the benefit of extending both lamp and circuit breaker life.

The NTC thermistor, when could, offers a high resistance (several ohms), limiting surge current through the breaker and lamp. The lamps, when cold, have a very low resistance-- which can cause a power on surge of several times their rated current (20-30 amps!). With the NTCs in series with the lamps, it minimizes the thermal shock to the lamps at start up by limiting the current. When everything warms up, the NTC's resistance drops to near zero, and the lamp's resistance increases.

I think that this can be of benefit to the automotive flashers. When wig-wagging for a while, the lamps are warm already, but they still have the start-up problem I mentioned... you are putting 20-30 amps through the tiny little relay contacts.

The devices are cheap, available at DigiKey, and install anywhere in series with the lamps.

Vern Little

[dan]

Originally Posted by Hard Knox

You gotta be kidding? Send me your address and I'll give you $22 for the wigwag. Give it a break. Do you squeak when you walk?

I bought something from B&C expecting it to be "solid state," because that's how it's marketed. Now maybe I'm naive and don't really know the true meaning of that term. But when I hooked that sucker up and it started clicking, I found it was an electro-mechanical device. Part of me still feels a little misled on that one. So I bought what I believe is the same device for $9 less.

Cheap? Sure. The savings translates into half an hour of flying. Every little bit counts.

[Tony Kirk]

Hey Dan,

I have the homebrewed AeroElectric wig-wag using the Tridon EL13A-2 flasher and a bridge rectifier, I got the flasher at the local NAPA store and the rectifier at rat-shack.

I thought it died a couple months ago when it started making a terrible noise like you described... "wahaaaaaaaaaaa", turned out to be a burnt-out landing light?!?

Changed the LL bulb and it's a wiggin and a waggin again!

[sprucemoose]

Originally Posted by Tony Kirk

I thought it died a couple months ago when it started making a terrible noise like you described... "wahaaaaaaaaaaa", turned out to be a burnt-out landing light?!?

I have the B&C flasher in the Moose, and while installing it, I found that if the load on one side was not hooked up, it didn't work, and made that "wwaaaaahhhhhhhhhh" sound. Having a burned out bulb would cause an open on that side, same as not hooking it up. Something to check.

[dan]

What's strange is that in the past I've had landing lights burn out (multiple times) and it didn't make that noise. The wig-wag flasher would just be silent when both loads weren't connected -- and the weird "new" sound is what led me to believe it was the flasher that went bad.

I confirmed today that indeed my right landing light isn't working. I swear it was working the other day when I checked!! Weird. The bulb filament looks fine. Other than that, I didn't have time to poke around to see if it's the bulb or the fuse. Will find out tomorrow or next time I have time. That'll be sweet if I jumped the gun and it's just the bulb and not the flasher (and I guess I'll have an extra flasher).

[osxuser]

So I guess the $200+ Pulselite (Certified system) is the way to go. I believe that it is totally solid state. That would definitely be the way to go if someone could reverse engineer (or just engineer their own). I would definitely pick up a solid state over relay.

[Ted Radclyffe]

Have a look at the circuit I put under the electrucal forum. It is totally solid state with only a small number of parts costing round $A10 which is about $7 US.
It is fun to make and works well. What can I say?
There is no radio noise. If a globe burns out the good lamp still flashes.

I used the idea that if the taxi switch was on, then the taxi light was on; if the landing ight switch is on then the landing light is on, but if both are on then there is a wig wag.

The box is small and can mount behind the switches and only requires lifting the taxi and landing light wires from the breakers and putting the box in series.

Have a look. The only advice is to use bipolar capacitors in the flip flop part of the circuit.


Infact there is a kit for $4 which works a wig wag as part of flashing jewelry which is how I first started the project. It took the addition of two power mosfets to complete the thing.

If you can wire an aircraft then sure as **** you can wire a simple piece of electronics.

[thallock]

Ted,

I couldn't find the thread for your circuit. Do you have a link?

Thanks,
Tracy.