kg2li

Member Since: August 18, 2008

Country: United States

  • Product ROB-10267 | about a year ago

    Nice little board, easy to use and at a good price. Had a working prototype using a PIC 12F675 with little effort. Ignore the warning that the silk screen is reversed for the min-max markings of the current adjustment pot, it works as labeled on the PCB for version 4.4

  • Product COM-08862 | about 2 years ago

    I added a few of the green 10mm Super Brights to my last order just for fun, Sparkfun # COM-08861. Just 5 mA was enough to make the green ones hurt your eyes; 40 mA lit up the room. I would imagine that these red ones are just as impressive.

  • Product KIT-10111 | about 2 years ago

    Yeah I love SparkFun but you guys are right, this design is all wrong. My calculator told me that the LEDs would go up in smoke with the resistor values shown; Then I realized that they were using an NPN as a high side switch. These transistors as shown can never saturate, that’s why the resistors are so small in series with the LEDs, They should be using the good old 2N2222 as a low side switch. The base resistors could be around 3.3K since the 2N2222 has more DC current gain, and the dropping resistors could be calculated assuming a VCE sat of 0.2 VDC. This would be much simpler, and transistors with different current gains could be substituted without having to recalculate the resistors to avoid blowing up the LEDs.

  • Product COM-08861 | about 3 years ago

    I added a few of these to my last order thinking they might be fun to play with, I was right. These things are bright !! at just 5 mA they are too bright to look into without discomfort. placed on the floor and aimed at the ceiling, 40 mA into one of these LEDs lights up the whole room.

No public wish lists :(