led dimmer (part 2)

mgandalf · electronics forum beginner Joined: 04 Oct 2007 Posts: 2

Ok, I've read up on people's questions and suggestions on led dimmers but I think my question may be a bit unique.

I have a PC which I've connected the HD LED up to the PC speaker port with an 83ohm resistor. Now, from what I understand, your typical PC speaker is driven by an Intel 8254 programmable interval timer which uses a 1.193182 MHz crystal. This sounds sounds just the thing (from what I understand) to dim an LED.

However, in all of my testing it seems there is a narrow range from 1 - 1193182 where the LED actually lights and within that window the LED only blinks rapidly at certain frequencies but never seem to dim.

Has anyone any recommendations?

Thanks, Mark.

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