Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: pomprocker on March 15, 2008, 06:36:57 PM
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I am trying to do this photoresistor math.
In the darkest operating light I am have the dial set at 200k and i'm geting a reading of 80.00
and set at 200k in a spot of sunshine coming in through the window I am getting 00.23
This give me 4.2 after the equation?
So should I use a 4.3k resistor?
I originally tried it out with just using the 1.62k resistor that was listed in the parts on the tutorial, but not getting very good results.
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80.00 what? kohms? and .23 kohms?
Make sure your units are correct.
sqrt(80k*.23k) = 4289.5 ohms
sqrt(80*.23) = 4.3 ohms
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80.00 what? kohms? and .23 kohms?
Thats what i'm trying to figure out. All I know is the multimeter was set in the 200k range and the display just said 80.00 or 00.23
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Go with the 4.3k, the other one is waaaay too low.
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man if the multimeter was at 200 then it is reading 80k,
u shouldknow about the multimeter first its the basic and one of the most reliable devices