No Strobe on my DLM FFB

brandomack · Post by **brandomack** » Mon Mar 21, 2011 11:02 pm

Hi all,

I'm just putting this out there,

I plugged in my federation flasher board and had running lights but no strobes.

is it my LM3909?

all connections have been checked and seem solid.

any ideas?

veedubb67 · Post by **veedubb67** » Wed Mar 23, 2011 9:34 am

Have you contacted Don?

Rob
Iwata Padawan

brandomack · Post by **brandomack** » Wed Mar 23, 2011 9:40 am

veedubb67 wrote:Have you contacted Don?

Rob
Iwata Padawan

Yes,

I posted this here too just in case.

Ziz · Post by **Ziz** » Wed Mar 23, 2011 4:05 pm

Did you try soldering directly to the LM3909 chip or did you put a socket on the board, solder to that and then put the chip in it? I killed several flasher chips until I figured out that the heat from the soldering iron was going in thru the contacts and frying the chip.

Put a socket on the board and snap the chip into it after all other soldering is done.

brandomack · Post by **brandomack** » Wed Mar 23, 2011 5:06 pm

i used the socket.

DLMatthys · Post by **DLMatthys** » Thu Mar 24, 2011 11:34 am

Try twisting the R10 50K pot left or right?
LM3909 notch or dot oriented on top?

I can only guess until I see pictures.

I have run across LM3909 duds before.
I have replacement chips

The happy news is that LM3909 chips are now NEW MADE again.
A petition of popular demand was forwarded to have these made again,
They are now colored in Green.

URL: http://store.americanmicrosemiconductor ... 3909n.html

brt · Post by **brt** » Thu Mar 24, 2011 7:41 pm

Google got me nowhere. No hint that new ones are out there. Every entry said they were old, out of production chips. Are they that much better than a 555 timer? You can get a strobe flash if you add a diode to a 555 circuit.

DLMatthys · Post by **DLMatthys** » Sat Apr 02, 2011 9:29 pm

brt wrote: You can get a strobe flash if you add a diode to a 555 circuit.

OK cool.... then show me a picture or schematic so I can prove that.
I'm not a AE engineer here... but I did stay awake in shop class.

Google this then... LM3909N
I think the "N" stands of National Semiconductor.

We have not heard back from Brandon if his strobe works on the FFB circuit.

brandomack · Post by **brandomack** » Sat Apr 02, 2011 10:14 pm

Weird,

I wasnt getting post nitifications..

The problem was solved in what best way I could - I used R4 to run the strobe. I ended up just doing the strobe behind the bridge, so it worked out fine. Due to time constraints the client preferred not to have to wait an extra month, so I went with the quick fix.

Thanks for the responses!

Brandon

USS Atlantis · Post by **USS Atlantis** » Sun Apr 03, 2011 5:03 am

DLMatthys wrote:
brt wrote: You can get a strobe flash if you add a diode to a 555 circuit.
OK cool.... then show me a picture or schematic so I can prove that.
I'm not a AE engineer here... but I did stay awake in shop class.

Google this then... LM3909N
I think the "N" stands of National Semiconductor.

We have not heard back from Brandon if his strobe works on the FFB circuit.

Don, That's how I do the nav beacons on my setup - just have to vary R5 and R6 to get it to be a strobe

Schematic

30 Second clip of circuit in operation

DLMatthys · Post by **DLMatthys** » Sun Apr 03, 2011 10:05 am

brandomack wrote:
The problem was solved in what best way I could - I used R4 to run the strobe.

So you did not use the LM3909N side of the board at all?

brandomack · Post by **brandomack** » Sun Apr 03, 2011 11:13 am

DLMatthys wrote:
brandomack wrote:
The problem was solved in what best way I could - I used R4 to run the strobe.
So you did not use the LM3909N side of the board at all?

Nope, she was dead as a doornail. Due to time constraints i had to make the quick fix and button her up. The build has been running behind and wouldnt handle a delay of up to a month.

brt · Post by **brt** » Sun Apr 03, 2011 11:52 am

DLMatthys wrote:
brt wrote: You can get a strobe flash if you add a diode to a 555 circuit.
OK cool.... then show me a picture or schematic so I can prove that.
I'm not a AE engineer here... but I did stay awake in shop class.

Google this then... LM3909N
I think the "N" stands of National Semiconductor.

We have not heard back from Brandon if his strobe works on the FFB circuit.

I used the second schematic at the bottom of this page to get my strobe circuit and I was pleased with the result. It's been awhile but I believe I used a 1N4148 diode. I don't remember the values that I used for R1 and R2.

http://wolfstone.halloweenhost.com/Tech ... rCalc.html

brt · Post by **brt** » Sun Apr 03, 2011 12:29 pm

So what I would like to do is use a 556 timer and put the nav lights on the first half and the use the diode on the second half for the strobes. 1 chip and both navs and strobes on it.

USS Atlantis · Post by **USS Atlantis** » Sun Apr 03, 2011 1:16 pm

brt wrote:So what I would like to do is use a 556 timer and put the nav lights on the first half and the use the diode on the second half for the strobes. 1 chip and both navs and strobes on it.

The nav lights are also "strobes", but of a different frequency

Your plan is good, just need a diode on the nav side of the 556 as well, the only difference between the two sides is the resistor/capacitor values