Making a lighthouse

[clivef5915]

Not sure if this is the right section but it seems electrical to me !
My granddaughter (aged 7) is having to make a working light house for a school project. The lighthouse is being made out of a 2 litre Coke bottle so plenty of space inside.
What do I need to produce a battery operated flashing light ? No need to worry about a revolving lamp, just static and flashing would be good enough.
Cheers for any help.
clive f

[flying scotsman123]

Small bike lamp? Not sure if it would fit, but it's a start...

[Emettman]

There must be a bought-in electronics answer, but I'm older than that, and more of a bodger.

A slow motor: 1 rev every 5-10 seconds would be nice.
Mount with shaft vertical projecting through a circular board say 2" across. (a chunk of balsa would do)
fix cylinder (cotton reel?) to shaft, on which mount a springy strip of brass with a good tail hanging off at the trail.
Around that stick pairs of pins in a circle so that brass strip wipes each pair in turn, making "on" switches

These can then give short and long flashes, or say three short flashes and a pause, depending on how far apart the pins are and how the pairs are arranged in the circle. I suspect the second pin of the pair should be slightly closer, but that would be trial and error.

Group all wires from 1st touched pin of pair together, and group all wires from 2nd touched pin of pair together, giving one "on-off " switch connection for the lighting circuit.

A 3v bulb, 2AA batteries. probably wired to drive motor too, or that could have its own supply, depending on space and convenience.
add external on/off switches to taste.

That's my first thought approach, but I am a bodger.

Chris.

[pointstaken]

For ***** sake, aren't they allowed to have any childhood ? (rant over)
I thought Express Models had a flashing thingamybob, or is that not allowed here ?

Dennis

[heda]

If you look on the 'auction site' you will find flashing led's, or things like flashing dog collars, bike light, all around £1. You might find the high street pound shop stocks flashing bike lights too.

Dave

[cowjam]

You can buy flashing LEDs, though the flash is probably quite fast (I just had a quick look and the found a 12v, 10mm white flashing LED that flashes twice a second). That'd be your easiest option.

You could use a non-flashing LED and a 555 timer (small and very cheap chip) to make it flash in a more controlled way, here's an instructable on it: http://www.instructables.com/id/Flashin ... 555-Timer/

[Emettman]

OK, now I've gone and done it.
I wanted a simpler build for a flashing light.

Light house is on a rock (with small but deep cave at water level.)
Sitting in bowl or tray of water (frying pan without handle might decorate to suit.)
At rim of water, slow motor (also hidden under rocks ) works paddle (rotary, back and forth, to taste) to make waves.
Inside cave, little float attached to microswitch makes and breaks light circuit as it bobs.

I'm not mad, just differently sane.

Chris.

(No, must not think about a fan-powered rotating light-screen around the lamp, actuated by rising air from a tea-light at the base of the lighthouse)

[Kentishman]

Morning Clive,
How about an electronic kit: https://www.quasarelectronics.co.uk/Ite ... g-leds-kit
Cost would be about £3 + VAT + postage + 9v battery. It would give your granddaughter the chance to learn how to solder, if she can’t already. You could also look on Maplin's web site.
Second, are there any pound shops near you that sell flashing novelty brooches or ties? These may be easier to find before Christmas but are usually dirt cheap and come with an attached battery and possibly a sound system, albeit ‘Jingle Bells’. You may even have one of these kicking around at home. They usually come with red LEDs, so a change to white may be necessary. Strip out the battery and light and insert in the lighthouse.
Regards
KM

[clivef5915]

Many thanks for the responses.
Went to Poundland yesterday and bought the bike front LED light .....erm for a £1. A bit of disassembly and wires lengthened and it all looks and works fine as a flashing lighthouse, if just a little fast.

[Emettman]

The clearly sensible route...

It's no longer a bodger's world, Max.
(I shall go the way of the sagger-maker's bottom-knocker.)

Chris

[b308]

Oh I don't know, he pulled it apart so it's bodging in my view, remember that bodging involves using anything to hand, just not for the purpose it was originally intended!

[Bufferstop]

By that reckoning the greatest bodge of all time happened in the Apollo 13 Lunar Lander when the the crew built an air scrubber from whatever was to hand under the guidance of the support team. And made a good enough job of it to get them home!
Colonel Stephens built his railway empire on bodged solutions. So we are in illustrious company here.

[clivef5915]

Found out whilst taking the grandkids to Escot (Devon) last year that a 'bodger' is in fact a skilled person from olden days who remained working the woods and forests when the industrial revolution took place. To be called a bodger now is a derogatory term for someones abilities, but not back then apparently.