I've encountered a bizarre LED behavior and am wondering whether anyone can shed any light on the reasons behind it.
I Recently built a simple miniature white-LED flashlight onto the top of a 9v battery clip, and took it out on a backpacking trip as a super-small flashlight.
After some time I realized that the light was beginning to strobe- first very quickly, and increasingly slower until it hit about 10 pulses per second. I took a closer look and realized that I'd put a much smaller resistor in series with the 2 white LEDs than I'd intended, and obviously a lot of current was flowing (up to 100ma, measured).
The strobing effect is what I'm interested in- how could an LED turn into an oscillator? Is this a failure mode of LEDs?
I'm an EE major and longtime hobbyist and have never seen anything strobe like this without good reason.
I Recently built a simple miniature white-LED flashlight onto the top of a 9v battery clip, and took it out on a backpacking trip as a super-small flashlight.
After some time I realized that the light was beginning to strobe- first very quickly, and increasingly slower until it hit about 10 pulses per second. I took a closer look and realized that I'd put a much smaller resistor in series with the 2 white LEDs than I'd intended, and obviously a lot of current was flowing (up to 100ma, measured).
The strobing effect is what I'm interested in- how could an LED turn into an oscillator? Is this a failure mode of LEDs?
I'm an EE major and longtime hobbyist and have never seen anything strobe like this without good reason.
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