[ List Subjects ][ Main Page ]
Subject: Re: Need to drive LED's from 12v source
[ View Followups ][ Post Followup ]
Date: 10/21/02 at 10:47 PM
Posted by: Ned Stevens
In Reply to: Re: Need to drive LED's from 12v source posted by Marcus Keeler on 10/21/02 at 7:20 PM:
Marcus, You can put LED's in series, they don't have to be the same color, just add up thier nominal voltage and subtract it from the source voltage and divide the result by the current.
You and also put them in parallel, but then they have to be the same color and preferably the same overall charastics. Rule of thumb voltage for RED LED's is 1.8 volts. So you could put all the LED's in series, 12V-(1.8+1.8+3.0+3.0)/10mA or
(12-9.6)/10mA or 240 ohms. The input voltage is not critical. It could go to 16 Volts and all would be well.
Post a Follow-up: