Single Landing Light Flasher? (not wing wag)

I have a single landing light and want to add a flasher to
the electrical system. I read somewhere that the
"wing wags" will burn out if you attach them to
only one light.

Any single light "flashers" that are recommended???
Thanks.

Bruce W.

I put one of these on my RV-4 to flash my landing lights. Been in there for two years with no problems.

B and C Specialties Solid State Flasher

Forgot to say and it should work just fine on one bulb. Just modify the schematic B and C has on their web site.

BruceW said:

I have a single landing light and want to add a flasher to
the electrical system. I read somewhere that the
"wing wags" will burn out if you attach them to
only one light.

Any single light "flashers" that are recommended???
Thanks.

Bruce W.

Click to expand...

You might measure the resistance of your landing light bulb and put a resistor with the same resistance on the other output of the wig wag. The wig wag won't know there isn't a bulb there. So that you don't have to do a bunch of math to come up with a wattage just go with something kind of big like a 3 watt resistor and it should work out.

Regards,

Add the resistor

Bryan Wood said:

You might measure the resistance of your landing light bulb and put a resistor with the same resistance on the other output of the wig wag. The wig wag won't know there isn't a bulb there. So that you don't have to do a bunch of math to come up with a wattage just go with something kind of big like a 3 watt resistor and it should work out.

Regards,

Click to expand...

This resistor will also prevent the needle of your ammeter (if you have an old fashioned analog one... ...) wiggling and distracting you...

Bryan's power calculations are a little bit shy....

If you have a 100 watt landing light bulb, a 1.2 ohm resistor should do it... needs to be about 50 Watts though (100 watts - same as the landing light, but with a 50% duty cycle, makes it 50 watts dissipated in the resistor).
I would use two 2.4 ohm resistors of 25 watts each in parallel to get the 1.2 ohms...

Mouser has them cheap... bottom right of this page...

http://www.mouser.com/catalog/628/526.pdf

gil in Tucson

Grumman does this with the old fashioned red flashing quartz bulb on top of the rudder...

az_gila said:

This resistor will also prevent the needle of your ammeter (if you have an old fashioned analog one... ...) wiggling and distracting you...

Bryan's power calculations are a little bit shy....

If you have a 100 watt landing light bulb, a 1.2 ohm resistor should do it... needs to be about 50 Watts though (100 watts - same as the landing light, but with a 50% duty cycle, makes it 50 watts dissipated in the resistor).
I would use two 2.4 ohm resistors of 25 watts each in parallel to get the 1.2 ohms...

Mouser has them cheap... bottom right of this page...

http://www.mouser.com/catalog/628/526.pdf

gil in Tucson

Grumman does this with the old fashioned red flashing quartz bulb on top of the rudder...

Click to expand...

Gil,

Yeah, I didn't do any math, just a weak guess.

http://www.angelfire.com/pa/baconbacon/page2.html

Best,

Bryan Wood said:

Gil,

I'm missing something here. If one channel has a 100 ohm light on it, placing a 100 ohm resistor to simulate a like bulb on the other output would require a 1.44 watt 100 ohm resistor. It is basic ohms law. I=E/R or 12/100 to find current. Then I squared R to get power. 12/100=.12
Square .12 and get .0144. Multiply times 100ohms = 1.44 watts. Here is an ohms law calculator that you can use to check the math. Using a smaller resistor (physically) will keep you from having to do a new weight and balance afterwards.

http://www.angelfire.com/pa/baconbacon/page2.html

Best,

Click to expand...

Bryan, you mixed up the ohms and watts. The bulb is 100 watt. Power = E^2/R so R=E^2/100.

R= 144/100 = 1.44 ohms.

-mike

Mike, You were to quick! I realized my mistake and couldn't fix it as fast as you were able to correct me on it. Anyway, with the above calculator you can enter the 100W and 12 volts to come up with the resistance in the bulb quickly. Then you can do the same to figure the resistor value and wattage needed. Oops!!! The point of the original post was to suggest using a resistor and I was busily watching deal or no deal on tv. Your right that I locked in on the 100w thing and reading it as if Gil was implying the lamp had a 100 ohm filiment. This locked me up because it just didn't compute. My mistake.

Best,

BruceW said:

I have a single landing light and want to add a flasher to
the electrical system. I read somewhere that the
"wing wags" will burn out if you attach them to
only one light.

Any single light "flashers" that are recommended???
Thanks.

Bruce W.

Click to expand...

Bruce:

Contact Eric Jones at Perihelion http://www.periheliondesign.com/
Eric can easily modify his wig wag for 1 light.

Jekyll

Auto Equipment

Is there some reason we can't just use an auto emergency flasher? I don't know, maybe the auto manufacturers have gone to a solid state flashing system by now. It just seems to me that some of these auto systems could be used in non-critical flight systems for less cost.

Thanks for the replies

See, that's why I love posting on this site. There is no way I could have figured out the electronics math. You guys are great. I barely know an ohm from a watt. I'll take your posts to the local aeroelectric expert who will translate for me. I understand the "put a resistor on it" part, just which one. Thanks again.

Bruce W.

Motorcycle headlight flasher

The situation of flashing a single 100 watt bulb was handled many years ago in the motorcycle industry. A handful of manufacturers made a "box" to flash the high beam. Sorry, I can't spout off any names but a web search should give some answers.

Since I am a frugal sort, I built my own (they were wanting $100 for them in 1980). It is a simple circuit using an NE555 timer chip to drive a Darlington paired transistor that can handle 10 amps (I have a 75 watt halogen bulb). The Darlington must be mounted on a heat sink. (I potted the first unit and it melted)

**EDIT** I was talking to my Dad about this e-mail (he helped me build my original MC flasher back in the 80's) and he said we probably should have used a field effect transistor (FET) instead of the darlington pair. The FET has much lower "on" resistance and will create less heat in use. **

4Hz is the fastest you can practically drive a halogen headlight. At 8Hz, the light no linger appears to blink due to persistance of vision and cooling physics of the bulb filament.

Anyway, I have more than 1000 hrs on it (70,000 road miles). Original bulb too.

Since I have no radio on the motorcycle, I cannot say how this fluctuation in current would affect radio systems in an aircraft, but I have never noticed any noise in a car radio that was in proximity.