Hi,
I have built 2N2222 based led flasher with 1 greenish-blue led, I wanted the LED to flash at 1Hz rate. One strange thing I have noticed is that when I change the voltage from 3.6V to 4.8v to get more brightness, the frequency increases. I have designed other flashers too and I don't find the frequency & duty cycle reliable with voltage change. Has anyone else noticed this? Any suggestion on how to keep the precise timing of the flasher over a range of 2.7-4v? (I have used 10k resistors, 470uf and 22uf capacitors).
I have built 2N2222 based led flasher with 1 greenish-blue led, I wanted the LED to flash at 1Hz rate. One strange thing I have noticed is that when I change the voltage from 3.6V to 4.8v to get more brightness, the frequency increases. I have designed other flashers too and I don't find the frequency & duty cycle reliable with voltage change. Has anyone else noticed this? Any suggestion on how to keep the precise timing of the flasher over a range of 2.7-4v? (I have used 10k resistors, 470uf and 22uf capacitors).