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Topic: Power supply for my LED modules (Read 2056 times) previous topic - next topic


The other end of the chain will connect to nothing so if I just "cap" them off?

Yes, either cut them short and tape them off, or coil and tape. Just don't let bare ends touch each other.



And he said "let there be light"  :D

Thanks guys, I know it was simple thing but im still scared of electricity & didnt wanna waste the lights.
Now I can lgo earn how to use my Arduino to control them with PWM ;-)

I've also learnt (after reading many times), that its not good to look directly into a lit LED  :0


"use my Arduino to control them with PWM "

For that you'll need a transistor to do the switching.
If you use a part like ULN2003 to control the connection from the -pin to ground, there are 6 PWM outputs on an arduino and you can individually PWM all of the modules.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


Thanks for that info CrossRoads............... More learning/info taken in.
After some research I found this response from a "Lefty" to a similar question.

"You can just use a simple NPN power transistor to switch all those led assemblies at the same time. Either just with on and off commands using digitalWrite() commands or vary the brightness by using a PWM supported output pin and using the analogWrite(pin, value) command. A TIP120 is a cheap popular choice of switching transistor. Wire it's emitter to ground, it's base wired to a series 500-1k ohm resistor with the other end of the resistor wired to the output pin. Wire all the +12vdc wires of the led assemblies together and then to your 12vdc source voltage. Then wire all the - leads of the led assemblies together and then wire it to the collector of the transistor. Finally run a wire from arduino ground pin to the - terminal of your +12vdc power source. The power source must be rated for the total current of all the led assemblies totaled"

Is this the same in my case, if i left them as one string? I have some TIP120's that I brought with my Arduino and other bits. I also have some salvaged TIP121's.




Great! The project is 600mA at the mo. It will go upto 1.2A in total. I'm just trying to get basic parts of a project together so I can then hit the coding side of things, then look to put it together in a more permanent/robust way.

I find learning much easier when I'm doing something wanted/needed with it.


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