Hi,
I'm doing a school project, and I was a little ambitious and chose to build a miniPOV3 (MiniPOV3 - Unending POV).
I now have show why I used 100 ohm resistors and I'm a little confused why the 100 ohm resistors worked, instead of 47 ohm resistors. (There is a guide on that website, and it says that BOTH 47 and 100 ohm resistors work, but the V=IR equation only works for the 47 ohm resistors).
Anyway, to make this more clear, here is the schematic (the zeners and the 4.7k ohm resistors are for the serial port, ignore them for now):
https://www.ladyada.net/images/minipov3/minipov3schem.png
Here's a part list:
MiniPOV3 - Parts
Now...I'm using 1.9V-2.0V Red LEDS, with a forward drop of 2V (I don't really understand forward drop, please explain
? They are also @ .02amps.
I'm using two 1.5V batteries, so it's 3V. You subtract the 2V forward drop so you get 1V
This means that 1V/.02amps = 50 ohms.
HOWEVER, I need it to equal 100 ohms! What am I doing wrong
?
This project is due tomorrow, and my entire write-up is complete, beside this equation...I don't understand what I'm missing.
I'm doing a school project, and I was a little ambitious and chose to build a miniPOV3 (MiniPOV3 - Unending POV).
I now have show why I used 100 ohm resistors and I'm a little confused why the 100 ohm resistors worked, instead of 47 ohm resistors. (There is a guide on that website, and it says that BOTH 47 and 100 ohm resistors work, but the V=IR equation only works for the 47 ohm resistors).
Anyway, to make this more clear, here is the schematic (the zeners and the 4.7k ohm resistors are for the serial port, ignore them for now):
https://www.ladyada.net/images/minipov3/minipov3schem.png
Here's a part list:
MiniPOV3 - Parts
Now...I'm using 1.9V-2.0V Red LEDS, with a forward drop of 2V (I don't really understand forward drop, please explain
I'm using two 1.5V batteries, so it's 3V. You subtract the 2V forward drop so you get 1V
This means that 1V/.02amps = 50 ohms.
HOWEVER, I need it to equal 100 ohms! What am I doing wrong
This project is due tomorrow, and my entire write-up is complete, beside this equation...I don't understand what I'm missing.