Author Topic: Running without mosfets  (Read 1319 times)

Offline soakes94

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Running without mosfets
« on: January 30, 2011, »
I'm not very good at this kind of stuff yet, I can build the bored's but when it comes to making changes I get a little stuck and confused. I want to run some white leds of the MR16, the leds need 3.4V and 30ma. What resistor should I use? I just want to run one led per channel, I was wondering if someone could point me in the right direction of what resistor I should use. Also am I right in thinking the resistor will go in place of the 4.7K Current limiter resistor? And one last question, do I still install the resistors and caps that sit between the mosfets and chips? That's it I think.

Thanks Steve

Offline RJ

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Re: Running without mosfets
« Reply #1 on: January 30, 2011, »
Yes replace the 4.7 current limiter resistor with a 1.5K resistor and this will be real close to 30ma. I get this from the chart in the 5940 chips datasheet.

Then leave off the resistors and caps that sit between the mosfets and chips. then jumper the mosfet pads where the oval shows and you will be good to go.

RJ
Innovation beats imitation - and it's more satisfying

Offline soakes94

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Re: Running without mosfets
« Reply #2 on: January 30, 2011, »
So the 1.5K will give me just under 30ma per channel, will the output voltage be the same as the input voltage just restricted to 30ma? And is it possible to run the board on 5v? On the board it mentions 7-24V but then I install a 5V regulator?

Thanks Steve