50 IR LEDs powered by 9v battery for 6 hours?


Joined Nov 4, 2008
i have done a lot of experiments with visible LED's. I am using some now that have a maximium forward current rating of 20mA. At present I have an array of 9 white ones. That is 3 in series with a 330Ω resistor and 3 groups in parallel. The total current is 30mA or 10mA per string. I don't know off hand what the MCD figure is, but I can look if up if necessary. Anyway they are so bright that it hurts my eyes. I have found that using a pwm circuit to only have them on for about 3mS every 12ms they are still real bright to the eye and the current drain now averages 30mA/4.

Going on step further I have built some name badge signs with flashing LED's.... some badges have about 20 LED's and I run the whole circuit from a 3V lithium coin battery. These badges L and W is the same as a business card.
They all use cmos 555's. The ones with white or blue LEDs have a LT1054 voltage pump to boost the 3V lithium battery up a bit.
If anyone would like pictures of these projects I would be happy to post the pictures.
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