Go Down

Topic: knight rider project using 1 watt LEDs (Read 1 time) previous topic - next topic

af77

I found a knight rider project here that I want to build:

http://fritzing.org/projects/arduino-knight-rider-with-8-blue-12v-led-modules/

I want to replace the LED modules with 1 watt LEDs like these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350668699726

or these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370725075035

and it will be powered with a battery similiar to this:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350585953725

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.

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.

Zapro


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:



The M is the load, place the LED-module here.

The mosfet can be replaced with a NPN transistor.

// Per.

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.

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.

Zapro


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.

// Per.

Go Up