Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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If I wanted to light 4 leds from 6xAA battery's, so a 9v total voltage, what Voltage leds would I require and would I put them series or parallel? Would they need resistors on each one?
Simple wiring diagrams would be appreciated
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Bart
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Registered: 19th Aug 02
Location: Midsomer Norton, Bristol Avon
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If you wired them in parallel only 1 resistor would be required, probably the easiest way tbh
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Won't that drain power more quickly though? Any ideas of voltages needed and resistance value?
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Dom
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Registered: 13th Sep 03
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quote:
Originally posted by Bart
If you wired them in parallel only 1 resistor would be required, probably the easiest way tbh
If they're in parallel then you should really apply resistance to individual LED's.
Steve - Grab 1.7/2/2.5V LED's, stick them in series and stick in a resistor. To calculate the resistance just use - R = ((supply voltage) - (combined LED voltage)) / (LED current)
[Edited on 14-10-2014 by Dom]
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Richie
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Registered: 3rd Dec 02
Location: Newport, Wales
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Just as easy to buy 5 predone for £2.80 and just parallel em up, assuming you haven't already purchased or have free LED's
http://www.ebay.co.uk/itm/Pre-Wired-3mm-LEDs-With-Resistors-Various-Colours-Free-UK-Postage-/140987464344?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item20d381fa98
http://www.ebay.co.uk/itm/Pre-Wired-5mm-LEDs-With-Resistors-Various-Quantity-Colours-Free-UK-Postage-/130902056745?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item1e7a5edf29
They run anywhere from 5v to 14v.
[Edited on 15-10-2014 by Richie]
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Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Problem with premade is I need to mount them as flush as possible to a PCB, those would sit away and flap around.
Rather then 4 lets go with 3,
So 3x 3v LEDs in series, each with a resistor?
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Richie
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Registered: 3rd Dec 02
Location: Newport, Wales
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http://led.linear1.org/led.wiz is your friend here
So for example - Maplin red 3mm led has 2v forward voltage and 35ma forward current
= single 100ohm 1/4w resistor in series
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Richie
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Registered: 3rd Dec 02
Location: Newport, Wales
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Also if you are doing PCB's ect - might want to look into SMD / nanopixels as they are much cleaner 
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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Went down to maplin in the end and the bloke helped me out, 3 leds in series with a correct resistor before them, hopefully should all work lol
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