Need Some Answers

berniedd said:

Hey guys, just curious, what is the maximum ON current a jumbo white LED can take safely if I use a 555 IC on it at a frequency of 15 Hz and duty cycle of 10% ? I'm going to experiment with it as a strobe.

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The ON time will be only 6.7ms. Your vision sees the brightness of a flash duration of about 50ms and longer as the same as continuous, so a flash duration of only 6.7ms will appear dimmer than if it was continuous.
Look on the datasheet of the LED for its max pulsed current rating.

audioguru said:

berniedd said:

Hey guys, just curious, what is the maximum ON current a jumbo white LED can take safely if I use a 555 IC on it at a frequency of 15 Hz and duty cycle of 10% ? I'm going to experiment with it as a strobe.

Click to expand...

The ON time will be only 6.7ms. Your vision sees the brightness of a flash duration of about 50ms and longer as the same as continuous, so a flash duration of only 6.7ms will appear dimmer than if it was continuous.
Look on the datasheet of the LED for its max pulsed current rating.

Click to expand...

Yes, that's right. I will have to operate the LED at a higher pulsed current that its normal continuous current rating to make it look bright enough. As a matter of fact, I'm going to string a number of LEDs in series and bunch them up physically to make for a brighter light. A condenser lens would also help.