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Re: How do you make a string of LED lights for an outdoor Christmas light display? [message #176116 is a reply to message #176113] |
Mon, 09 July 2012 06:02 |
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If it were me I would buy them already made up!
But...
If you wish to have several LEDs on at the same time it may be possible to connect them in series. This prolongs battery life by lighting several LEDs with the same current as just one LED.
All the LEDs connected in series pass the same current so it is best if they are all the same type. The power supply must have sufficient voltage to provide about 2V for each LED (4V for blue and white) plus at least another 2V for the resistor. To work out a value for the resistor you must add up all the LED voltages and use this for VL.
Example calculations:
A red, a yellow and a green LED in series need a supply voltage of at least 3 × 2V + 2V = 8V, so a 9V battery would be ideal.
VL = 2V + 2V + 2V = 6V (the three LED voltages added up).
If the supply voltage VS is 9V and the current I must be 15mA = 0.015A,
Resistor R = (VS - VL) / I = (9 - 6) / 0.015 = 3 / 0.015 = 200,
so choose R = 220 (the nearest standard value which is greater).
Hudman wrote on Sun, 08 July 2012 23:12 | How do you make a string of LED lights for an outdoor Christmas light display?
Radio shack sells packs of LEDs, but how do I make them light up? I don't know much about electronics. Learned right away that they aren't like light-bulbs that light up by going directly from a battery to the bulb.
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led spotlight bulb
led flood light
LED Tube
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John Ruff
Chandler, AZ
1975 Eleganza
WA3RIG
If I use ZDDP in a new car - will the tappets go flat?
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Re: How do you make a string of LED lights for an outdoor Christmas light display? [message #176118 is a reply to message #176116] |
Mon, 09 July 2012 06:28 |
C Boyd
Messages: 2629 Registered: April 2006
Karma: 18
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Good morning John... You are up early this morning playing with the forum spammers..
John Ruff wrote on Mon, 09 July 2012 07:02 | If it were me I would buy them already made up!
But...
If you wish to have several LEDs on at the same time it may be possible to connect them in series. This prolongs battery life by lighting several LEDs with the same current as just one LED.
All the LEDs connected in series pass the same current so it is best if they are all the same type. The power supply must have sufficient voltage to provide about 2V for each LED (4V for blue and white) plus at least another 2V for the resistor. To work out a value for the resistor you must add up all the LED voltages and use this for VL.
Example calculations:
A red, a yellow and a green LED in series need a supply voltage of at least 3 × 2V + 2V = 8V, so a 9V battery would be ideal.
VL = 2V + 2V + 2V = 6V (the three LED voltages added up).
If the supply voltage VS is 9V and the current I must be 15mA = 0.015A,
Resistor R = (VS - VL) / I = (9 - 6) / 0.015 = 3 / 0.015 = 200,
so choose R = 220 (the nearest standard value which is greater).
Hudman wrote on Sun, 08 July 2012 23:12 | How do you make a string of LED lights for an outdoor Christmas light display?
Radio shack sells packs of LEDs, but how do I make them light up? I don't know much about electronics. Learned right away that they aren't like light-bulbs that light up by going directly from a battery to the bulb.
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led spotlight bulb
led flood light
LED Tube
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C. Boyd
76 Crestmont
East Tennessee
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Re: How do you make a string of LED lights for an outdoor Christmas light display? [message #176312 is a reply to message #176311] |
Wed, 11 July 2012 09:34 |
tphipps
Messages: 3005 Registered: August 2004 Location: Spanish Fort, AL
Karma: 9
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Senior Member |
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Sorry that I did not catch that one. However, LED's are the way to go for lighting. I have installed a string of LED's, replacing some of my interior lights with them. Also have installed LED fixtures in the hallway, the bathroom, and over the twin beds in the rear of the coach (It's an Avion). Nice to have the non-heat producing LEDs in place of incandescent bulbs. Probably will last longer than anything else in the GMC.
Pet project is an LED substitute for the rear lights, then the front turn indicators.
Tom, MS II
2012 Phoenix Cruiser model 2552
KA4CSG
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