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Old Dec 01, 2006, 02:16 PM
Boats on the brain!!
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Arnold, Mo.
Joined Jul 2005
4,553 Posts
The bulbs in my set don't have a lip on the bottom of the LED. Between that and the bulb shape, it would make it easy to chuck th bulb up in a lathe and cut some ridges in the sides.
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Old Dec 01, 2006, 03:06 PM
Registered User
Houston Area
Joined Oct 2006
34 Posts
I did some looking and found this is probably a "Bethlehem Lighting Indoor/Outdoor 50-Lamp 5mm Wide-Angle LED Lighting Set".

They are also available at Amazon:
Multi-color
http://www.amazon.com/dp/B000F54934
Red:
http://www.amazon.com/dp/B000F54952
Green:
http://www.amazon.com/dp/B000F5494S
They're out of clear:
http://www.amazon.com/dp/B000F50W7G/

Here's the manufacturer's website - they don't have much data:
http://www.bethlehem-lights.com/lights.htm#LED

Looks really cool! Might have to get a set for the tree and another for the boat!
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Old Dec 07, 2006, 09:52 PM
Sea Dragon-Lover
Umi_Ryuzuki's Avatar
PDX, OR
Joined Dec 2002
10,201 Posts
Do some testing before you mount anything to a boat.

The White, Blue, and Green LED are 4volt.
The Yellow, Red, and Orange LED are 3 volt.

I set up a 4.05 volt power supply, and all fo the yellow, red, and green LED failed.

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Old Dec 07, 2006, 11:07 PM
Boats on the brain!!
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Arnold, Mo.
Joined Jul 2005
4,553 Posts
Quote:
Originally Posted by Umi_Ryuzuki
I set up a 4.05 volt power supply, and all fo the yellow, red, and green LED failed.

Sizzle, sizzle, fry, smoke, oh sheet.
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Old Dec 07, 2006, 11:19 PM
Taking care of the pond.
MILLERTIME's Avatar
USA, CA, Fresno
Joined Apr 2004
7,275 Posts
Quote:
Originally Posted by MILLERTIME
Look here.
LED calculator
http://led.linear1.org/1led.wiz


Don M.
Umi did you miss this?
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Old Dec 07, 2006, 11:22 PM
Taking care of the pond.
MILLERTIME's Avatar
USA, CA, Fresno
Joined Apr 2004
7,275 Posts
LED basics
http://led.linear1.org/why-do-i-need...r-with-an-led/

Don M.
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Old Dec 07, 2006, 11:26 PM
Sea Dragon-Lover
Umi_Ryuzuki's Avatar
PDX, OR
Joined Dec 2002
10,201 Posts
Quote:
Originally Posted by MILLERTIME
Quote:
Originally Posted by Originally Posted by MILLERTIME
Look here.
LED calculator
http://led.linear1.org/1led.wiz


Don M.
Umi did you miss this?
Yeah, but the instructions say 4volt LED.
So I would have put 4 in for the forward voltage...
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Old Dec 09, 2006, 10:29 AM
Registered User
Olympia WA
Joined Nov 2004
1,027 Posts
You might try the following website, sorry but I just found his card again. I met Tim Anderson at a model railroad show and he has lots of information on his site on led's. You can contact him with questions but he has a lot of information on his site also. The site is www.ngineering.com. Jerry J
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Old Dec 09, 2006, 11:14 PM
milesc
Loveland, Colorado
Joined Nov 2006
53 Posts
Forward voltage will turn on the LED; you can have a reverse voltage in some apps but no greater then 3 to 5 volts. Led should always have a resistor placed in the circuit. Silicon type LEDs need as little as .7 volts and gallium arsenide and gallium phosphide types need 1.6 volts.
+V = supply voltage - Vf = LED forward voltage / If LED forward current
+V-Vf
If
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Old Dec 11, 2006, 07:44 PM
Registered User
Madison, MS
Joined Oct 2004
2,453 Posts
I'd appreciate some advice on utilizing LEDs on a model cabin cruiser. I would like to use a Radio Shack 5mm 2.6 VDC 28 mA 10 mcd red LED for the port navigation light, powered by a 1.5 V AAA or AA battery. I would use a Radio Shack 5mm 2.1 VDC 25mA 6.3 mcd green LED for the starboard nav light, powered by another, separate 1.5 V battery. I would have the remaining wiring and electronic components (motor, receiver, switches) completely separate from the above lights.
I know that this is a very unsophisticated, perhaps inefficient setup, but (1) it adheres to the KISS principle and (2) I can understand it and implement it.
Questions: Will it work? Will the LEDs that it lights last a while? (If they're not really bright, that's alright with me; I'd prefer longer LED life to extreme brightness.)
Or, would I be better off trying to find (higher voltage) grain-of-wheat bulbs for the nav lights?
Thanks all.
Bill
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Old Dec 11, 2006, 08:03 PM
Boats on the brain!!
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Arnold, Mo.
Joined Jul 2005
4,553 Posts
Trying to drive a 2+ volt LED with a 1.5 volt battery would not work very well, very dim if anything. You would have to start with 3 volts and use a resistor to drop the voltage and limit the current. LED's are very rugged and are designed to last 10,000+ hours at rated levels if they are not overdriven.

(battery voltage- LED's forward voltage) divided by LED's current = resistor value
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Old Dec 11, 2006, 08:24 PM
Registered User
Madison, MS
Joined Oct 2004
2,453 Posts
Hello Green-boat,
Thank you for your advice. Another question that I have is whether any precautions need to be taken when soldering wires to the conducting "legs" of the LED? Will the heat of the soldering iron harm the LED? Will the soldering iron generate a small current that could burn out the LED during soldering?
Thanks again,
Bill
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Old Dec 11, 2006, 08:39 PM
Veni, Vidi, Feci
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Motor City
Joined Dec 2004
12,350 Posts
Solder very quickly... but if worried, put an alligator clip or purpose-made heat sink on the leg.

Pat M
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Old Dec 11, 2006, 08:48 PM
Boats on the brain!!
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Arnold, Mo.
Joined Jul 2005
4,553 Posts
Too much heat will destroy an LED. I use a 30 watt iron and have no problem but then I have been soldering stuff together for 30+ years now. Have you soldered anything together before, if not I would suggest some practice. Irons don't generate any currents but there are grounded and ungrounded irons. If you are working with static sensitive components then grounded irons are mandatory. Do keep in mind that LED's are polarity sensitive, meaning that the + and - must be connected correctly if the LED is going to work.
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Old Dec 11, 2006, 09:21 PM
Registered User
Madison, MS
Joined Oct 2004
2,453 Posts
Yes, I have in the past soldered small electrical components successfully - small incandescent light bulbs, wires, small switches, small motors - but have never fooled with LEDs and their idiosyncracies. Yep, I know to use rosin-core solder on electronics; acid core is verboten.
Bill
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