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Topic: Selecting the correct resistor? (Read 850 times) previous topic - next topic

DJDevon3

I don't see anything in the starter book on how to select the proper resistor for use in each project.  A long string of resistors come in the package but I don't see any way (other than color banding) on how to know which one to select.  Project 2: Spaceship Interface simply says to use a 220 ohm resistor.  OK so how do I know which one of those 50 or so included resistors is the right one to use?  I think it would be handy to include a reference page on each color coded resistor included in the kit.  I'm very new to electronics and it seems that some instructions assume that I already know what a 200 ohm resistor looks like.

knut_ny

Google "resistor color codes"
U'll find that those 220R  (red red brown  +gold) are suitable as current limiters for LEDs
Other /much used/ resistor value is 10k  (+/-)  often used as pullups. (brown black orange +gold)
Thees resistors /gold/ adre within 5%
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The 1% tolerance have 4 color bands; 1.st three for value 4th for additional zeros, and at last brown
Ny

DJDevon3

Oops.  It's actually included on Page 41 which is after it assumes you've completed the project.  Seems a bit out of order there don't you think?  It should be on Page 33 which is prior to placing the first resistor on the board.  Arduino is all about logic so having the resistor chart after the first project that uses a resistor doesn't make any sense.

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