Author Topic: LED Magnifying light  (Read 4209 times)

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ruddycrazy

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LED Magnifying light
« on: December 19, 2010, 04:58:14 AM »
G'day Guy's,
                 Rotten weather here today so spent some time up in the shed and with that 4 pin zif connector I got for my touch screen module being so small it was time to fit one of my desktop magnifiers out with some led's for a low DC voltage light. I used commanda's circuit 4 which was just 2 resistors, a BC547 transistor and a 2n7000 fet. For now I've just hooked it up to a 12 volt DC plug pack and put a on/off switch and it does work nicely.

@ 12 volts it draws about 143mA of current which is only 8.9mA for each led. I used a 1 meg ohm resistor for Rg and a 12 ohm resistor for Rs. One thing I did find with the voltage @ 17 volts the current shot up 430mA but by using that 12 volt plug pack will ensure the led's don't get too much current.



Cheers Bryan
« Last Edit: December 19, 2010, 05:46:44 AM by kurt »