# LED's and power to run

Discussion in 'The Projects Forum' started by B.A. Klim, Mar 29, 2009.

1. ### B.A. Klim Thread Starter New Member

Mar 25, 2009
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How many LED's can be ran in series or parallel? How much power or volts would be required to run 60 LED's at once? Is there a way to run all 60 at once or would they have to be split up into 3 or 4 groups? What kind of resistors would be required to make them all run at the same brightness? Could capacitors be used to run all 60 at once or would this just blow out the circuit? Would solid state relays be a good way to good or would they serve no purpose?

2. ### Wendy Moderator

Mar 24, 2008
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3,047
Why would you want them in a continous chain? One LED goes out, they all go dark. It would be better to have small groups on a regulated power supply. Resistors are cheap.

Then there is also the issue of high voltage. LEDs are inherently safe voltages, doing what you want to would definately put them in the danger zone. Figure 2.1V per red LED at 60 LEDs adds up to 126 Volts, even more for other colors.

There is no real limit other than what common sense would dictate.

Last edited: Mar 29, 2009
3. ### SgtWookie Expert

Jul 17, 2007
22,201
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When LEDs die, they may go open or they may short out. Either is a problem.

If shorted, and you have a long string of LEDs, the rest of the LEDs in the string may get too much current, causing them to rapidly fail.

If one in a long string opens up, it can be lots of fun finding the dead LED.

We like for "n00bs" to start off experimenting with low voltage (under 50v) projects that are isolated from mains power by a transformer. High voltage can easily kill you, and we want people to come back.

4. ### Trike New Member

Mar 29, 2009
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Use low voltage AC and put leds on half phase (by stringing the leds by common polarity) and you can higher output as the alternate strings of leds are off on each alternate half cycle. Use resistors and be mindful of what your doing, but you can have fun playing with this idea. An RC network can shift freq enough to give you slower 'blink rate' Put the leds into a word as it were and the other half in an other word and you could flash 'Open' and Sale on the same sign. Be creative.

Feb 19, 2009
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6. ### B.A. Klim Thread Starter New Member

Mar 25, 2009
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Thanks been every helpful so far.