LED's......advice please....

Greeners · 20th November 2008, 20:36

Complete numpty when it comes to LED's...

I need to wire three small LED's together off a 12v feed.

Done a trawl of ebay and there's a huge choice.

Can someone give me some pointers please.

black olive · 20th November 2008, 21:07

depends on colour and type, typically they run at between 10 and 30mA and drop between 2 and 5 volts depending upon colour.
you can get this infro from the datasheet.

pop it up and Ill give you the calcs for a suitable resistor value ( and will pop you some inthe post if I have them in the shack )

capese21 · 20th November 2008, 21:21

It is easy to work out this link explains it

http://www.kpsec.freeuk.com/components/led.htm

Ultra LED`s sell them

http://www.ultraleds.co.uk/single-re...ard-p-375.html

E.

podge · 20th November 2008, 21:22

Lots of interesting stuff on here.P.
http://www.ultraleds.co.uk/

I AM NOT SPAMMING!!!MY REPLY CROSSED WIH THE ONE ABOVE!!!

black olive · 20th November 2008, 21:24

wot:

good links there !!

I can thoroughly recommend Ultraleds, I have used their products on Black olive, sidelights, number plate lights, and interior lights, top quality and super service

The_Monk · 21st November 2008, 08:11

What colour LED's do you want, I've been buying them in the 1000's for a large project (non car related). Buying them from Hong Kong works out loads cheaper than ultraleds.

Greeners · 21st November 2008, 08:28

I need three, probably 3mm, possibly 5mm, certainly no bigger.

They need to be wired in series (due to the space limitations) so do I still need a resistor on each LED or can I use one big one?

How close does the resistor have to be to the LED, or doesn't it matter ?

So many questions.

The_Monk · 21st November 2008, 08:46

You can wire them in series with one resistor. I have 5mm white 20ma with a 3.4 forward voltage you can have if you only need 3.

The_Monk · 21st November 2008, 09:18

You would need a 90 ohm resistor or there abouts to run three of those LEDS on 12v by the way

StevenWilliams · 21st November 2008, 12:49

I have loads of RED, GREEN, BLUE 3mm & 5mm along with a load of resistors.

If you tell me what you want I'll post the to you.

20th November 2008, 20:36	#1
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	LED's......advice please.... Complete numpty when it comes to LED's... I need to wire three small LED's together off a 12v feed. Done a trawl of ebay and there's a huge choice. Can someone give me some pointers please. __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

20th November 2008, 21:07	#2
black olive I really should get out more....... 260 SE vin 214 ( last mark 1 260 ) Join Date: Dec 2006 Location: Lancashire Posts: 2,009 Thanks: 1 Thanked 8 Times in 4 Posts	depends on colour and type, typically they run at between 10 and 30mA and drop between 2 and 5 volts depending upon colour. you can get this infro from the datasheet. pop it up and Ill give you the calcs for a suitable resistor value ( and will pop you some inthe post if I have them in the shack ) __________________ [SIGPIC][/SIGPIC]

20th November 2008, 21:22	#4
podge I really should get out more....... Rover 75 Tourer CDT CLUB SE Copper Red Mica Dec 01 ....now deceased....replaced by2003 Royal Blue T Join Date: Nov 2007 Location: North Warnborough, Hampshire Posts: 2,398 Thanks: 9 Thanked 69 Times in 20 Posts	Lots of interesting stuff on here.P. http://www.ultraleds.co.uk/ I AM NOT SPAMMING!!!MY REPLY CROSSED WIH THE ONE ABOVE!!! __________________ 01 75 CDT Club SE Tourer..."The Rover 75 is a British-built car to be proud of." B.M.Ws loss........OUR GAIN!!!!!!!! http://knowledgerush.com/wiki_image/...arp.300pix.jpg http://farm1.static.flickr.com/167/3...b847e1c5_m.jpg

20th November 2008, 21:24	#5
black olive I really should get out more....... 260 SE vin 214 ( last mark 1 260 ) Join Date: Dec 2006 Location: Lancashire Posts: 2,009 Thanks: 1 Thanked 8 Times in 4 Posts	wot: good links there !! I can thoroughly recommend Ultraleds, I have used their products on Black olive, sidelights, number plate lights, and interior lights, top quality and super service __________________ [SIGPIC][/SIGPIC]

21st November 2008, 08:28	#7
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	I need three, probably 3mm, possibly 5mm, certainly no bigger. They need to be wired in series (due to the space limitations) so do I still need a resistor on each LED or can I use one big one? How close does the resistor have to be to the LED, or doesn't it matter ? So many questions. __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

20th November 2008, 21:21	#3
capese21 This is my second home MG ZTT 180 Sports Auto. Join Date: Dec 2006 Location: London Posts: 3,930 Thanks: 18 Thanked 180 Times in 143 Posts	It is easy to work out this link explains it http://www.kpsec.freeuk.com/components/led.htm Ultra LED`s sell them http://www.ultraleds.co.uk/single-re...ard-p-375.html E.

21st November 2008, 08:11	#6
The_Monk I really should get out more....... - Join Date: Nov 2006 Location: - Posts: 2,586 Thanks: 0 Thanked 3 Times in 2 Posts	What colour LED's do you want, I've been buying them in the 1000's for a large project (non car related). Buying them from Hong Kong works out loads cheaper than ultraleds.

21st November 2008, 08:46	#8
The_Monk I really should get out more....... - Join Date: Nov 2006 Location: - Posts: 2,586 Thanks: 0 Thanked 3 Times in 2 Posts	You can wire them in series with one resistor. I have 5mm white 20ma with a 3.4 forward voltage you can have if you only need 3.

21st November 2008, 09:18	#9
The_Monk I really should get out more....... - Join Date: Nov 2006 Location: - Posts: 2,586 Thanks: 0 Thanked 3 Times in 2 Posts	You would need a 90 ohm resistor or there abouts to run three of those LEDS on 12v by the way

21st November 2008, 12:49	#10
StevenWilliams This is my second home Rover 75 Saloon 2.5 V6 British Racing Green. 81,000 miles and counting Join Date: Apr 2008 Location: Crawley, West Sussex Posts: 6,183 Thanks: 0 Thanked 2 Times in 2 Posts	I have loads of RED, GREEN, BLUE 3mm & 5mm along with a load of resistors. If you tell me what you want I'll post the to you. __________________ [SIGPIC][/SIGPIC] Rover 75 2.5 2000 Club SE. British Racing Green. MEMBER NUMBER: MMMDCCXXVI Looking for: 7 seater