Are there any other parts that I will need so I can run the 1 watt LEDs, or can I just hook them up to where the LED modules are hooked up? Meaning, will they drain the battery too quickly, or will they run at all? Thank you.
The example is not correct.
A led needs a constant current.
So you can't feed a 12V led with a 12V battery. The current will be a lot too much or a lot too less.
I assume that there are specific power supplies for those 12V leds.
Normally a led with a resistor is switched on and off.
Krodal:
The example is not correct.
A led needs a constant current.
So you can't feed a 12V led with a 12V battery. The current will be a lot too much or a lot too less.
I assume that there are specific power supplies for those 12V leds.
Normally a led with a resistor is switched on and off.
It's quite obvious that the LED's used in the example are LED's sold with pre-mounted resistors for 12V operation, that's why it says 12V LED's
The high power LED's OP has found are meany for Halogen light replacement, so they have built-in power regulation and are fine for 12V operation.
To control the LED's with the arduino, do like on this diagram:
Zapro, you could be wrong.
Led modules often consist of a few leds parallel and serial. Sometimes 16 'leds' are used inside the module with 4 rows and 4 columns. So the result would be 4 leds of 3V is 12V.
af77, you have to find more specifications for those leds. Do they have some current limiting inside. If they can be used as replacement for halogen lights, they could have.
Krodal:
Zapro, you could be wrong.
Led modules often consist of a few leds parallel and serial. Sometimes 16 'leds' are used inside the module with 4 rows and 4 columns. So the result would be 4 leds of 3V is 12V.
Yes - I COULD be wrong, but the LED's OP have found are MR11/G4 LED replacements, they are constructed so they can run on 12V DC or 12V AC from a standard Halogen lighting transformer. I work in an electronics store and sell these kinds of things on a daily basis, so I actually know what I am talking about.
I'm not so sure. If the MR16 LEDs are halogen replacements, they almost certainly contain a switching regulator and a large input capacitor. This will give rise to large current pulses when the mosfet switches on. Preferably you should tap into the switching regulator PWM control signal in the built-in regulator. See this thread: http://arduino.cc/forum/index.php/topic,139792.0.html.
I'm also going to be using 2 TLC5940's. If I ran the LEDs through a ULN2803 and then through the TLC5940, would that work instead of using the NPN transistors? In my project, I will be using 6 LED strips like in the example in my first post, and 24 of the 1 watt LEDs. If what I suggested won't work, what would?
I was thinking of doing the same thing, I had my circuit setup to use 5mm LED's... which left me with a dilemma, space/pins - So i used the ULNxxxx whatever number as a darlington
transistor array supplying up to 500ma ...
That's my Greenie in Action, but like you I wanted something more Powerful.. like the 1watt LED's.
Use 1 watt LED's with a bunch of 2222a transistors and create a monster bright knite rider kit, that or go buy 12v automotive lamps for the car and paint them all red