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Thanks guys will have a go at adding another resistor. 

9 minutes ago, Getunderit said:

. Or even add a 500 ohm trimpot, and vary the brightness to your desire.

Not seen these before very interesting, I will look into using these. Thanks. 

 

 

For now testing the lights, you see the upper cabin is going to need some filler. 

 

IMG_20180618_222637.jpg
IMG_20180618_222554.jpg

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If possible, try and add material to block the light from entering unwanted areas.

I had used a sheet of card, glued next to the LED, as a blind.

Also have used aluminium foil (don't short the LED leads with this!), to block areas out.

 

The trimpot has three connections. You only need two. One must be the centre connector, the other can be either one of the other two.

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8 hours ago, Getunderit said:

If possible, try and add material to block the light from entering unwanted areas.

I had used a sheet of card, glued next to the LED, as a blind.

Also have used aluminium foil (don't short the LED leads with this!), to block areas out.

 

The trimpot has three connections. You only need two. One must be the centre connector, the other can be either one of the other two.

Thanks for that info Getunderit. 

 

So in an attempt to to stop some of the light leak I have cut a hole in from the inside of the upper deck, I should be able to get to all the leaking parts from here. 

Now the engine are very leaky and I'm not sure if I want to leave it like that........ Spooky glow  👻🤖...... I suppose most of it will dim with back a prime and the colours on top. 

 

I really should have thought about lighting this before building most of it.... Oh well its all good fun. 🤪

 

You can just about make out the details added for the jolly-boat docking bay. 

 

IMG_20180619_070932.jpg
IMG_20180619_070753.jpg

Edited by rockpopandchips

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48 minutes ago, Getunderit said:

Try and dim it first. You may see the problem in a different light 😉.

Do you have any idea what resistor value I should go for on the trimpot? Thanks.

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Just read back and you mentioned 500, thanks.

 

OK ordered a pack of 5 of those and a bit of brass rod to run the wires down to a base, it will  give me a bit more room for batteries switches etc, so I guess that means I will now be making a small dio for this build and I'm thinking rock and ocean..................

Edited by rockpopandchips

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19 minutes ago, rockpopandchips said:

Do you have any idea what resistor value I should go for on the trimpot? Thanks.

I would use 500 ohm. Any bigger than 1,000 (1K) ohms and you lose range of dimming.

LED resistance is calculated by the LED's operating voltage (average of 2 volts) and its current capacity (average 20 milliamps (mA)). The resistor is for any voltage over 2 volts. 

Okay, you are using 9 volts. You can dim the LED by also using a smaller voltage supply (perhaps 5 volts, which can easily be obtained from computer shops selling transformers with a 5 volt output.

 

To calculate LED resister (R).

R = (power source voltage minus 2 volts) x 1000. Then divide this by 20 (mA)

Okay, for 9 volts R = [(9-2) x 1000] / 20

R= (7 x 1000) / 20

R=7,000 / 20

R= 350 0hms

I suspect that the resistor with your LED has a 390 ohm value.

 

An extra 100 - 500 ohms will dim the LED quite nicely.

Or the added 0-500 ohm trimmer will make R = 390 - 890 ohms.

Edited by Getunderit

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4 minutes ago, Getunderit said:

To calculate LED resister (R).

That is a very useful bit of info there Getunderit - I’ve stashed that away in my little book of things; many thanks!

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Awesome to see someone teaching Ohm's Law! That said, online "LED calculators" are super handy :) Lots out there to choose from. 

 

NB: It's good to check the LED datasheet (or your supplier's webpage) to find the forward voltage - the 2V quoted above is roughly right for red & yellow-green, blue & white & clear green usually require a little over 3V. Lots of info here:

https://www.evilmadscientist.com/2012/resistors-for-leds/

 

If you're using higher voltage supplies (anything over 3V) you can run some of the LED strings in series, which wastes less energy in the limiting resistors.

 

(Edit: Didn't phrase that clearly, I mean you can have strings of series LEDs in parallel across the supply. Which might save wire as well as battery life.)

 

Cheers,

 

Will

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1 hour ago, Will Vale said:

If you're using higher voltage supplies (anything over 3V) you can run some of the LED strings in series, which wastes less energy in the limiting resistors.

 

In my simplistic knowledge I have everything wired in parallel just because that's all I know, so I wire the upper decks and front view deck ( x3 blue lights) in a series and then in to the parallel circuit? So the 3 blue LED`s would share the 9V between them, 3v each. 

Edited by rockpopandchips

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LEDs with their own resistor is meant to be connected in parallel.

 

LEDs without a resistor can be connected in series with, or without, a single resistor. The thing is that if a LED uses 2 volts to operated optimally, then it requires 2 or less volts to operate. However, if you connect 5 LEDs in series, it can be hooked up to (5 x 2 volts = 10 volt) supply or less. If you added, lets say, 7 LEDs in series to a 9 volt battery, each LED will be running on about (9 / 7 = 1.3 volts), and would be dimmed down. However, running 2 LEDs, in series, on a 9 volt supply (9 volts / 2 LEDs = 4.5 volts per LED) will instantly blow the LEDs. (open circuit)

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20 hours ago, rockpopandchips said:

the upper cabin is going to need some filler.

I quite like the fact that light is leaking. It adds to the rundown, shabby theme of these ships.

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9 hours ago, rockpopandchips said:

In my simplistic knowledge I have everything wired in parallel just because that's all I know

That's the easiest and most fault-tolerant, definitely.

 

If you had a 9V supply and three blue LEDs you would want to look up the forward voltage. If it's 3V or more you won't drive them properly from 9V. If it's under 3V you'll need to calculate a suitable limiting resistor. Be aware that battery cell voltage drops off as the battery discharges (especially with alkalines) so if you're close to the rated supply voltage your LEDs are likely to go out long before the battery is drained.

 

Example: If you had three 20mA red LEDs with forward voltage 2V in series across a 9V supply:

 

Total forward voltage desired = 6V

Voltage drop desired across resistor = 9V - 6V = 3V

Current desired = 0.02A

 

Ohm's Law: V = I * R

(Where V is voltage in volts, I the current in amps, and R the resistance in ohms.)

 

So R = V / I = 3/0.02 = 150 ohm

 

Pick the next highest value that you have handy, e.g. 150, 180, 220, 330 ohms.

 

You can also calculate the power dissipated as heat by the resistor by multiplying the current and voltage:

 

P = V * I

So P = 3 * 0.02 = 0.06W

 

So tiny resistors rated for 1/8th watt are just fine.

 

The pay off is that your three red LEDs are drawing 20mA, whereas if they were in parallel they'd be drawing 60mA and running down your battery three times quicker.

 

Cheers,

 

Will

 

 

 

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On 20/06/2018 at 02:26, Pete in Lincs said:

I quite like the fact that light is leaking. It adds to the rundown, shabby theme of these ships.

FWIW I agree with Pete. I think the leaky spooky light - especially around the engines looks great!

 

Maybe that’s how the anti gravity drive works.

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@Will Vale and @Getunderit thanks so much for your help, it really helps and has cleared up a few gaps in my limited understanding of making lighting. 

 

And back to the building so I had gathered a few more bits for the build, the base, brass tube and the trimpots recommended by @Getunderit thanks. 

 

IMG_20180622_211347.jpg
IMG_20180622_211331.jpg

 

I have also added the bay doors. 

 

IMG_20180621_201223.jpg

 

I might also add this? 

 

IMG_20180621_221823.jpg

 

Edited by rockpopandchips

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Second that, it's definitely part of the McQue look.

 

Will

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So as I need to get this up in the air so I can add the rear stabilisers and rudder, I have made a start on the base. My thoughts on this is this is an unmanned way point in some mountain pass. 

 

IMG_20180624_085323.jpg

 

 

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:lol: LOVE IT!

That fin changed the character so much. Hope you keep it on there.

Like the mountain top waypoint idea for a diorama.

As a waypoint, are you going to have old fashion direction markers?

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9 minutes ago, Getunderit said:

As a waypoint, are you going to have old fashion direction markers

I hadn't thought of that but now you mentioned it, definitely thanks. 

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On 24/06/2018 at 16:58, rockpopandchips said:

Did this in half time....... 

 

IMG_20180624_122005.jpg

 

I know that your idea is an unmanned waypoint, but when I see this I want something happening on the ground. Perhaps some sort of trade exchange or delivery. ...Just me  thinking out loud, perhaps I better shut up 😁

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1 hour ago, Jaktis said:

I know that your idea is an unmanned waypoint, but when I see this I want something happening on the ground. Perhaps some sort of trade exchange or delivery. ...Just me  thinking out loud, perhaps I better shut up 😁

:lol: Have a space guru meditating under the tree. Yeah, I better shut up too.

 

@rockpopandchips, love the knolly tree. Much like a Bonsai.

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