Lighthouse Flasher!

[ActingLikeAKid]

No, this isn't a story about a deranged person who skips about nautical markers in his birthday suit.

I'm building the Fliskits Nantucket Sound (which looks like a lighthouse) and thought it would be fun to stick an LED in the top.

I almost abandoned this idea because I was going to need to get an LED, battery holder, switch, wires, figure out a way to do the flashing.... then I found an old LED flasher for a jack-o-lantern. Cut it open and it looks ... PERFECT. The flash rate is a little high, but the price was perfect.

Here's what I found when I cut it open:


(yes, that is a broken iPod)

...Here's my plan (and tell me if I'm about to do something stupid...)...First, I'm not going to worry about replacing batteries. We had a similar flasher literally run for days with no issues, and this should be on for 20-30 minutes at a time, tops. So I just need to expose the LED and the switch.

Here's what the tip of the rocket looks like:


1. I lower the "ball" a little so that there's room for the LED.
2. The "roof" is just a cardboard cone that's glued to a fiber plate that is attached to the top of the support poles. My plan: Cut out the battery holder and remove the switch from the flasher. Discard the rest. Cut an LED-sized hole in the plate above the plate above the poles.
3. CA the PCB (with LED attached) to the plate.
4. Using Rocketpoxy that's been cured to the "acts like putty" stage, make two "standoffs" on either side of the PCB. (or just cut two little pieces of balsa and use CA) Glue the battery box to that (so it's not touching)
5. Cut a second small hole in the fiber plate; mount the switch, pointing down, into that hole (so that you reach in to turn it on)

Does this make sense? Am I missing anything?

 

[soopirV]

Mods, close this down for false advertising! I thought we were going to see something interesting!

My only suggestion, and I'd love to see this when it's done- would be to scrap what appear to be 2-3 LR44-sized cells, and go for a single CR2032. While it's maybe a little dangerous, it's quite common to see leads soldered directly to the battery case (there's a site that tells you how to do it, fwiw: https://www.cr2032.co/soldering-article.html). If there are 2 LR44 in there, you'll be fine- if 3, the CR2032 cell may not have enough voltage to drive the circuit.
Reason for this is to get rid of the battery box and associated difficulty. All you really need from the device is the PCB; making their parts fit your rocket may be more trouble than it's worth!

 

[ActingLikeAKid]

Hm. It's 3xLR44. I really like the idea of scrapping the battery case ... what if I taped 2x2032 together, soldered to one side of one, one side of the other? Something like

_____ pos lead
|
---------
cr2032 #1
---------
cr2032 #2
---------
|____________neg lead

 

[Micromeister]

I've been working on the MMX version Plum Island Sound Lighthouse. I've been converting Odd-Rocs into Night flying rockets for decades.

First off your flashing LED is the right idea. I'd also suggest adding a steady burn LED to the project. We found that Flashing LED's and Strobes can be lost against a starry night sky. Adding the steady burn allows the rocket to be tracked more easily all the way to touch down.

2nd: There are any number of smaller 3v. lithium coin cells at will power this small draw LED lighting for more then a hour in 12.5mm and 10mm. a single cell is more then enough for most any Mod-Roc flight including extended search recovery

Below are a couple pic of these 3v lithum coin cells and various coin cell holders available from most any electronics shop or on-line. I get most of my LED, resistors, wire, Coin Cells and Cell holders from Allied Electronics on-line or All Electronics.
Hope this helps a bit.

 

[soopirV]

Hm. It's 3xLR44. I really like the idea of scrapping the battery case ... what if I taped 2x2032 together, soldered to one side of one, one side of the other? Something like

_____ pos lead
|
---------
cr2032 #1
---------
cr2032 #2
---------
|____________neg lead

Might be tough to solder the two batteries together, since you're not supposed to directly heat the case (at least according to the source I linked to...I haven't done this myself!). What about an itty bitty 2s LiPo? OR!! Even easier, pretend I never spoke up and keep with your original plan- sorry! :blush:

 

[soopirV]

I've been working on the MMX version Plum Island Sound Lighthouse. I've been converting Odd-Rocs into Night flying rockets for decades.

First off your flashing LED is the right idea. I'd also suggest adding a steady burn LED to the project. We found that Flashing LED's and Strobes can be lost against a starry night sky. Adding the steady burn allows the rocket to be tracked more easily all the way to touch down.

2nd: There are any number of smaller 3v. lithium coin cells at will power this small draw LED lighting for more then a hour in 12.5mm and 10mm. a single cell is more then enough for most any Mod-Roc flight including extended search recovery

Below are a couple pic of these 3v lithum coin cells and various coin cell holders available from most any electronics shop or on-line. I get most of my LED, resistors, wire, Coin Cells and Cell holders from Allied Electronics on-line or All Electronics.
Hope this helps a bit.

John- I have to ask- your photos are always specific to the discussion at hand, and so well captioned! Do you document absolutely every step of every build and have them annotated and meticulously cataloged, or are you immediately identifying which build has which example, and deconstructing it and shooting the photos when needed? Either way, Bravo!! Amazing!

 

[MikeyDSlagle]

You can always remove the LED from the PCB and extend the leads, allowing you to mount the PCB elsewhere and just the LED in the top of the lighthouse. Just remember LEDs require correct polarity. The flasher circuit should be able to flash multiple LEDs.

And.. Look at the circuit, are there any resistors? Increasing resistance MAY lower flash rate. Depending on the circuit of course.

Mikey D