MX005 - Controlling Hi Power LEDs

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Benj
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MX005 - Controlling Hi Power LEDs

Post by Benj »

Article: http://www.matrixmultimedia.com/article.php?a=52

If you have any questions for the author or comments on the article, please post them below.

mfun
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Re: Controlling Hi Power LEDs

Post by mfun »

Benj,

Were you aware this example will not open in the trial V4 version? (unexpected file format) is the error I get.
Regards,

Mike

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medelec35
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Re: Controlling Hi Power LEDs

Post by medelec35 »

Great tutorial!
My concern would be there is no base current limiting resistor, so it would be like shorting an uc pin o/p with a silicon diode, so o/p will drop from 5V to 0.7 ish Volts. Limited by internal circuitry of uc.
Or are you saying this base limiting resistor can be omitted if pulse width is narrow enough?
Martin

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Benj
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Re: Controlling Hi Power LEDs

Post by Benj »

Hello Mike

Sorry you need version 4.1 You can download the update from here.
http://www.matrixmultimedia.com/support ... .php?t=563

Hello Medelec

You are quite right the transistors could do with base resistors. I will update the schematic images accordingly. Thanks for the spot.

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Re: MX005 - Controlling Hi Power LEDs

Post by sroy »

i want to know, how can i generate 4shifted phase pwm @ 100khz with the controller 33fj16gs502 , please send some application notes or hints for those application.
Last edited by sroy on Tue Sep 06, 2011 4:23 pm, edited 1 time in total.

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Benj
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Re: MX005 - Controlling Hi Power LEDs

Post by Benj »

Hello,

You should be able to do something like this using my Article and software PWM example file as a template. You can import it into Flowcode for dsPICs by using the File -> Import menu.

Using the master interrupt count as a master clock you should then be able to prescribe phase offset and mark/space ratios for each of your PWM channels.

Have a go and see how far you get. If you get stuck then please upload the program you have so far and we may be able to provide extra hints or support on how to accomplish the project.

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