So, thanks to Wayneh and Bernard for answers to other questions on this circuit.
Here's the final one:
What should I worry about when removing R5, R27 & R31? Here're my observations with experimentation:
without R31, the Green LED draws a maximum (recorded over several hours of the local "Oldies" station driving the circuit) is 805ma
With R31, max draw is about 450ma. I like the way the colors look at the higher current, and according to the datasheet, the green LED in this module has Max rated drive current of 1A. It says that the recommended operating current is 700ma with a footnote that higher currents are possible, but requires adequate cooling. (One other thing, the 800ma was a peak, not constant, since the purpose of the circuit is to 'flicker' the LEDs. I would think average may be down around 300ma or so.)
I've built what seem to be pretty good heat sinks for the TIP120s and the LED module, as all run mildly warm.
So, my question is if nothing if overheating, should'nt it be okay to run these LEDs without the current limiting resistor as long as my measurement assures that the 1A max limit isn't exceeded?
Thanks!
Here's the final one:
What should I worry about when removing R5, R27 & R31? Here're my observations with experimentation:
without R31, the Green LED draws a maximum (recorded over several hours of the local "Oldies" station driving the circuit) is 805ma
With R31, max draw is about 450ma. I like the way the colors look at the higher current, and according to the datasheet, the green LED in this module has Max rated drive current of 1A. It says that the recommended operating current is 700ma with a footnote that higher currents are possible, but requires adequate cooling. (One other thing, the 800ma was a peak, not constant, since the purpose of the circuit is to 'flicker' the LEDs. I would think average may be down around 300ma or so.)
I've built what seem to be pretty good heat sinks for the TIP120s and the LED module, as all run mildly warm.
So, my question is if nothing if overheating, should'nt it be okay to run these LEDs without the current limiting resistor as long as my measurement assures that the 1A max limit isn't exceeded?
Thanks!
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