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Help with Alternating 12 volt DC Headlight flasher "WIGWAG"

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Ronv said they were P channel which I didn't know. Oh well!

Post the first LTpice file. I'll try to figure it out. I did try to do something complicated in LTSpice.
 
Ronv said they were P channel which I didn't know. Oh well! Post the first LTpice file. I'll try to figure it out. I did try to do something complicated in LTSpice.

KISS, it's obvious they are P channel.... look at the symbol, look at the circuit. Also your idea will not work even if they were N channel. Look it is OK. There is no need to do any more work. I'm very happy with the basic design (thanks RonV). I am not going to change it... parts are ordered. Cheers.
 
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So I think you guys are little above my knowledge even though I can build most of these circuits. What I'm looking for though is a wiring diagram or schematic either one for a dual alternating headlight flasher. Not attempting to talk down to anyone by this but, what I mean by dual alternating, is that the left light flash twice and right light flash twice. So it would basicly be like your wig wag flasher just two flasher per light instead of one. Also, trying to play around with a high beam override which would cause the steady burn of the high beams when the high beam relay switch on the vehicle is engaged, then continue flashing once the highbeams are off.
 
Mosfets with a very high current rating are used because the filament of a 13.2V/60W incandescent light bulb draws 4.5A when it is 2000 degrees C but draws 45A to 68A when at room temperature.
 
So I think you guys are little above my knowledge even though I can build most of these circuits. What I'm looking for though is a wiring diagram or schematic either one for a dual alternating headlight flasher. Not attempting to talk down to anyone by this but, what I mean by dual alternating, is that the left light flash twice and right light flash twice. So it would basically be like your wig wag flasher just two flasher per light instead of one. Also, trying to play around with a high beam override which would cause the steady burn of the high beams when the high beam relay switch on the vehicle is engaged, then continue flashing once the highbeams are off.

Just buy an over the counter CAR wigwag or headlight flasher. Most of them come with like 7 or more patterns, including single, double, triple flash and at different rates.... They all have built in highbeam overide... the installation is pretty simple from reading the manuals.

Seriously the over the counter stuff from brand names like: Whelen, Code 3, SHO-ME, NOVA electronics, SoundOff, re all excellent and about $40 or less. They have selection of flash patterns, single, double, triple, medium, fast, faster flash rates, all in one unit. You can select one or cycle through all patterns manually or automatically. They have an override switch for high beam or night operation. Do some research and try and down load the manuals.... it should become clear to you how they install and operate. Here are typical ones:

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Manual for Whelen uhf-2150a:
https://www.electro-tech-online.com/custompdfs/2011/08/13289.pdf

I did not do the over the counter module because of weight, most of all. All the ones for cars are "POTTED", sealed for heavy duty use, weighing a few pounds. A pound or two on a car is no big deal, way too much for a small plane. Also I needed to control left and right lights for steady ON, separately. Last I wanted to use one switch to do all this. I could have made a store bought one work, but a custom one was more fun, learned a lot, it's lighter and has simpler switching for my application.

Just for grins, the way I ended up doing it with a micro processor, which also makes it easy to do double flashes. There are many kinds of MICROPROCESSORS. I started with a PICAXE, all on one little 8 DIP IC chip. They cost a few bucks and can be programed with free software from your PC. You can program it to flash lights in any pattern or patterns you want. It was a fun project, got me back into some simple programing (not so simple at first being rusty on code and no "basics" expert).

BTW the over the counter headlight flashers all must use a small microprocessor. This project would be too complicated for you I think. IF YOU WANT ONE FOR RC MODELS, there are some small ones you can buy on eBay for a few bucks that will flash many LED's per some pre programmed patterns like emergency lights on a model car, just like the real deal.
 
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I appreciate the help, I appologize, I just kinda skimmed through and didn't pick up on the small plane installation. The micro processor isn't really to complicated for my knowledge, just a little bit more time than I'd want to spend finding hex codes and so forth. However, I would like to let you know that whelen engineering and I think maybe federal signal, and NOVA usually carry a full line of recognition, taxi, and landing light flashers that would be be sufficiant for what you are trying to do.

Also, I'd recommend changing all of you par 36 or 46 lights out to LED, not because I'm a fan, but because in a small plane like a cessna or a beechcraft, it would save you a whole lot of power. Little more expensive to replace though. Just some info I would like to share, you may have already researched all these, and from your post I'm sure you've already got your flasher built.

Again, thanks for the info.
 
I appreciate the help, I appologize, I just kinda skimmed through and didn't pick up on the small plane installation. The micro processor isn't really to complicated for my knowledge, just a little bit more time than I'd want to spend finding hex codes and so forth. However, I would like to let you know that whelen engineering and I think maybe federal signal, and NOVA usually carry a full line of recognition, taxi, and landing light flashers that would be be sufficient for what you are trying to do.

Also, I'd recommend changing all of you par 36 or 46 lights out to LED, not because I'm a fan, but because in a small plane like a cessna or a beechcraft, it would save you a whole lot of power. Little more expensive to replace though. Just some info I would like to share, you may have already researched all these, and from your post I'm sure you've already got your flasher built. Again, thanks for the info.

First you don't FIND CODES ... ha ha ... you have to write them. Micros are in C/C+, basic and assembly languages, then compiled. I don't know many people who programed in machine or hex direct. Good for you if you do.

Yes Whelen specifically does have aviation lights, strobes, nav, landing, taxi lights..... I don't think they make a landing light wig-wag controller for an airplane, but if they did it would cost $400 dollars! No thanks. I would get a $35 one for a car.......

If this was for a certified plane and I wanted a WIG-WAG (not required by FAR's by the way), I would need to have a PMA part, from a company like Whelen, and a STC or one time FAA field mod approval to be legal. However this is an experimental amateur built kit plane, so we have a little more flexibility. I can put what I want in. HOWEVER if it's a nav or strobe light it must meet the FAR's (federal aviation regulations). That is why LED's have not been on planes, they could not meet the requirements. However I guess the new bright ones do... I have doubts if they do.

To repeat automotive emergency headlight flashers are heavy, and it would require me to put in several toggle switches to get all the functions (verses one switch design). Aviation light stuff is silly expensive. The product I am making has no competition (under $400). I don't plan on going through PMA or STC approvals. I am making two, one for me and one for a friend. As I go to airshows, if enough interest in the kit plane market (EAA), I will make a batch and sell them.... There is already a product like it on the market for business or corporate planes/jets. It is expensive. My product can be sold for under $100 and is for light experimental plans to control all the landing taxi wigwag functions with one low amp switch, a single toggle or rotory switch. The lights are about 4-6 amps each so they take big switches. Having his allows a small switch and multi controls in one switch saving panel space.

As far as LED's, they over rated.... WHY DO YOU RECOMMEND IT? They are cool, but they are not all goodness. The very high bright LED's are EXPENSIVE! You also need a gaggle of them to make enough Lums or Lux. They still use current and get hot. Whelen has certified LED lights. LED's for the experimental guys has been used for years, some were crude, some more sophisticated, but they all still used a shotgun of LED's. I was not impressed.

Now with the certified stuff, I'm still not impressed. Costs more and I don't think they give the same visible negotiable light. Real incandescent lights and Xenon flash tubes for strobes are MUCH BRIGHTER than LED... I have flown side by side with experimental planes with LED and ones with traditional lights. The traditional ones are brighter and more noticeable in day. We use our night lights, navs, landing lights during the day to add more visibility to avoid midair collisions ...

LED promises to have better MTBF (mean time between failure), but these are not commercial planes flown many many thousands of hours a year, where down time and maintenance are factors. Gen aviation planes might fly a few thousand hours in the life of the aircraft, 100-150 hours a year. So long life is no big deal. Lower current is nice, but not a big deal. Right now the best of the LED stuff for planes, even experimental planes is costly.
 
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GMC

I've been on vacation.... Did you build it ok?

HEY ronv... how ya doing my friend.... I got the 555 working fine, perfect 50% duty and right rate (had to add a diode). This picture shows both Left and Right Channels flashing alternating at about 90 fpm or 1.5 Hz kind of slow for an analog scope so I had to turn out the light and rely on the persistence of the CRT on the Tek 2235A to show the nice pattern. I made some simple RC flip flops that worked well but the pattern was not even close as sharp as these. They were very ugly

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**broken link removed** (don't laugh I used my old Science Fair for protoboarding)


Then I chucked it all. I went off into PICAXE land. Still using a lot of your great help and ideas, thanks again. The switch to a PICAXE simplifies switching, increased capabilities and flexibility and can be customized easier, just going to the microprocessor. I went with PICAXE for prototyping, may be low "production". There are better cheaper micros but this was easy to get into with the free simulator programs and compiler. $3.50 per chip (plus $1.00 for a voltage regulator) verses $0.50 for a 555 is more cost. Still it is slick. Basic is easy to work with. I brushed off my programing skills and made some nice code that runs very efficiently. I can program any flash rate or patterns I want. I can even have a few to select from based on non volatile memory that the user can configure. With some clever "switch logic" and programing, the user can configure a few light patterns in the second flash pattern (if one wants to use two different wig wag patterns, it's optional). There is non volatile memory in the PICAXE that you can read or write on with the code. With some a switch throw during power up, with in an allotted time, a few seconds. I might put a seperate program button on the box. WAY OVER KILL FROM THE ORIGINAL 555.

I have it designed around a single 5 or 6 position, 3 pole rotary switch, selecting: Off, L, R, Both, Flash, Flash (2nd bonus pattern anything I want and can be configured to some preset patterns). I could use a single three position toggle, off-both-flash to access less functions. I could use two toggles to get more functions. The rotary is the easy way to get all the functions in one switch, but the user is not limited. I didn't want any button pushing to CYCLE through patterns, which I could have done, but I want simple SWITCH POSITION showing what function you are on.... no guessing. That is the way planes are, switch position is the setting, no ambiguity. With the micro processor, I set the switch logic to be open (off) and ground on (pulling a high to a low on the PICAXE). The code looks for the voltage on the switch channels. There are 5 I/O channels to the IC processor. I am using 3 as input, two as output. There is also a serial interface and power making up the -08 Picaxe.

I have the chip working and programed. I need to get the power transistors along with all the mechanical stuff, packaging, case, connectors, heat sink and making the final board. That will be easy. I am using a PCB that matches the PCB, so it will be a direct duplicate. I am not going to do a custom board and have them made, yet. If I want to make a bunch I might, but the prototype now. PCB Breadboards with a few jumpers still makes for a clean nice board. The wiring turned out to be easy. It is deciding if I want to use a terminal strip, Molex, wires with Fast-on connectors and the case and mounting of the board and heatsink that has been the time consuming part.

I have put it on the back burner for other projects. I have a Mouser order about to go in to make the final prototype.

I upgraded the FQP27P06 MOSFETS. The ones I am going to get handle more amps (FQP47P06 or STP60NE06L-16) and make less heat. Even though I only have 4.5 amps to switch I wanted it to be able to handle more, with some head room. They also run a little cooler (Rthj-case of 0.94 vs 1.24 Celsius/Watt). Since I using them for steady current as well as flashing, a small heat sink with passive cooling will be needed to keep it from getting too hot. I don't remember but it was approx +2.5 watts to dissipate. The case is aluminum and the power transistors will be thermally attached to the box as part of the cooling, but an additional small internal heatsinks will be added as well, all electrical isolated from the case of course. I am trying to keep the temp rise under 60F. It will need to have some vents in the case as well.

Having fun. I will post the final product. Here is a rough draft. I have changed it a lot since. The power transistors need to go near edge of board to mount on case. Again the biggest part is packaging it.

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Modulating a high current incandescent:
> use a micro to PWM cycle from 100% to ~25%
> micro allows total flex in op parameters
> ~25% keeps the filament warm = no cold current & longer life (low thermal shock)
> let it take a 1/2 sec or so for initial turn on (minimize initial thermal shock)

I built mine ~5 yrs ago for driving lights ~100W @ 12V for longer bulb life. Wound up using it for off/dim/bright on a custom bikes' single filament headlight set. Good Hunting... <<<)))
 
Sounds like you have been busy. The micro sounds like a good idea. Gives the flexibility to do whatever you want. I have a tube of IRF4905 FETs. Let me know if you would like a few and I'll throw them in an envelope.
 
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