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Author Topic: LED's- Diodes?  (Read 2672 times)

Brian60

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LED's- Diodes?
« on: November 14, 2015, 02:58:12 PM »

I'm tying together several led circuits- 8 of them. So I have 8 + feeds and 8 - returns. I want a single - return.


Now if you tie all the -'s together, any back current from whichever + circuit is on is enough to give a faint glow in the other circuits. Now my rudimentary electronics tell me if I insert a diode into each of the - returns I can block this, like so.....



      to battery  <---- -+――――― from negative feeds
                                  DIODE 1N4001

am I correct please.

Brian60

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Re: LED's- Diodes?
« Reply #1 on: November 14, 2015, 04:05:41 PM »

This quick diagram might explain better. Ignore the colours its just to make things clearer.

aeronut

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Re: LED's- Diodes?
« Reply #2 on: November 14, 2015, 04:27:53 PM »

Brian, an LED IS a diode, so you shouldn't need to add another in series.  I'm at a bit of a loss to understand why you get a faint glow from the others if only one is on - in your diagram, if you only close one switch, all the others are open, so there's no return path for the current.  %%
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Brian60

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Re: LED's- Diodes?
« Reply #3 on: November 14, 2015, 05:52:05 PM »

Yep I know that leds are diodes :} , I was just wondering if I was getting some sort of a back eddy in the current with all of the negatives being joined at a common point.

I'll connect them all again later and do another check when its darker, it could be I was getting reflected light from the window on to the domes of the led's.

But now I come to think of it, even if there was a back eddy in the current, it couldn't complete a circuit because the other switches are open :embarrassed: :embarrassed: :embarrassed:

aeronut

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Re: LED's- Diodes?
« Reply #4 on: November 14, 2015, 05:57:28 PM »

What voltage are you applying to the LEDs?  It's normal to have a current limiting resistor in series with each one.  This won't be the cause of your problem however.
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Umi_Ryuzuki

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Re: LED's- Diodes?
« Reply #5 on: November 14, 2015, 07:13:18 PM »



I ground my mast, and solder the the return from each LED to the brass.
There are two circuits and each set light up only when their switch has bee closed.

 :-)

Brian60

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Re: LED's- Diodes?
« Reply #6 on: November 14, 2015, 08:03:23 PM »

Me too Umi. The mast lights are all grounded via the brass mast, the leds wired in pairs with a current limiting resistor. However all the other lights throughout the superstructure are wired in pairs, the resistor in the positive lead and all the negative leads coming together at one connector. So far there are 10 leds on the mast, 2 smleds inside the bridge. an led embedded in each of the bridge consoles (4) 2 stern lights, 6 inside the lower cabins, and two wired to p/s nav lights.  I still have to fabricate and add 10 external companionway strip lights, from 1mm x 2mm smleds embedded in resin. All of these functions are on seperate switching circuitry, so they can be turned on individually.

I saw on one of your discussions on another forum, a switching unit that illuminated the leds in a very realistic way. Sadly it was from 2010 or thereabouts and  search as I may, I have not been able to find if it ever progressed.

Umi_Ryuzuki

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Re: LED's- Diodes?
« Reply #7 on: November 15, 2015, 07:32:27 AM »

The unit you saw was designed and built by PeterS. and was designed for his
Abeille Bourbon. Leen Boers also uses the lighting system for his Maersk Master.
 https://picasaweb.google.com/105202506859524458881/BauberichtABEILLEBOURBON02
 
Not sure if he is still making them. I know I missed a nice hull when I had to put
off for the that recession. I baubled about it twice, and decided no...
I will ask Peter about the lamp circuit and see if he is still making them.


Regards.
 ok2

The Old Fart

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Re: LED's- Diodes?
« Reply #8 on: November 15, 2015, 07:56:44 AM »

Me too Umi. The mast lights are all grounded via the brass mast, the leds wired in pairs with a current limiting resistor. However all the other lights throughout the superstructure are wired in pairs, the resistor in the positive lead and all the negative leads coming together at one connector. So far there are 10 leds on the mast, 2 smleds inside the bridge. an led embedded in each of the bridge consoles (4) 2 stern lights, 6 inside the lower cabins, and two wired to p/s nav lights.  I still have to fabricate and add 10 external companionway strip lights, from 1mm x 2mm smleds embedded in resin. All of these functions are on seperate switching circuitry, so they can be turned on individually.

I saw on one of your discussions on another forum, a switching unit that illuminated the leds in a very realistic way. Sadly it was from 2010 or thereabouts and  search as I may, I have not been able to find if it ever progressed.


switched remotely from the transmitter?
Mine do, 8 remotely switched circuits.

Brian60

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Re: LED's- Diodes?
« Reply #9 on: November 15, 2015, 09:57:57 AM »

Cheers Umi. I have the pages bookmarked and I downloaded all of Peters Picasa albums, you can pick up a lot of build tips from his photo's!

Old Fart, the unit we are talking about actually makes the lights flicker as they are switched on circuit by circuit. So they look like flourescent tubes starting with a flicker, or the halogen spots come on slowly and increase in intensity/brightness, just like the real thing. If I can get his video or a link I'll post it.

The Old Fart

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Re: LED's- Diodes?
« Reply #11 on: November 15, 2015, 12:46:16 PM »


Old Fart, the unit we are talking about actually makes the lights flicker as they are switched on circuit by circuit. So they look like flourescent tubes starting with a flicker, or the halogen spots come on slowly and increase in intensity/brightness, just like the real thing. If I can get his video or a link I'll post it.

That's a nice touch,
I'll have to re program my chip to ramp up/ down the floodlights.
Flickering bridge and cabin lights, on startup, easy program alteration.

At exhibitions, I switch over to demo mode, which cycles through the various lights.

Umi_Ryuzuki

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Re: LED's- Diodes?
« Reply #12 on: November 15, 2015, 07:39:07 PM »

I liked how Peter had the one misbehaving flourescent on his Xbow.
https://picasaweb.google.com/105202506859524458881/NewProjects#5296364783034581618


Leen Boers' Maersk Master.
https://www.youtube.com/watch?v=nTqvGR8u92E
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