Hi all! I'm Andy and holy heck I'm confused!
My first question is about the experiment in Figure 1-54.
Parts List:
9V Battery
1K Ohm Pot
470 Ohm Resistor
1 Basic Led
When I put my DMM on the the pot and resistor to read the resistance levels, I'm coming up with some confusing numbers. I'll include photo of where I am setting my DMM to make sure I'm using the proper setting.
Here are the numbers I'm getting:
(Reading pot, when pot is set to MAX resistance) = 4.76V shown on my DMM
(Reading pot, when pot is set to MIN resistance) = 25.9mV
(Reading resistor, when pot is set to MAX resistance) = 2.34V
(Reading resistor, when pot is set to MIN resistance) = 6.56V <---- **
I don't understand what is going on with the last line. Everything seems to make sense to me until that number goes up! Sorcery I tell you!!!
I was expecting no difference in resistance readings because I thought a resistor is just a static number that it brings current down. Can somebody please explain to me why the pot resistance number goes down, but the resistor resistance is going up when the pot is lowered?
My second question is about Fig 1-58.
It shows what I think is a combined resistance of 4.5V + 4.5V? The picture then shows 9V DC on the '+' and 0V DC on the '-'. Does this mean it's indicating we 'start' with 9V DC, but then because of the resistance it tries to travel through, it 'ends' with 0 DC?
I think what may be causing me all this confusion is I don't really know how resistors work yet, or maybe I'm just missing something else.
Thank you for any help or useful tutorial links you can provide!
My first question is about the experiment in Figure 1-54.
Parts List:
9V Battery
1K Ohm Pot
470 Ohm Resistor
1 Basic Led
When I put my DMM on the the pot and resistor to read the resistance levels, I'm coming up with some confusing numbers. I'll include photo of where I am setting my DMM to make sure I'm using the proper setting.
Here are the numbers I'm getting:
(Reading pot, when pot is set to MAX resistance) = 4.76V shown on my DMM
(Reading pot, when pot is set to MIN resistance) = 25.9mV
(Reading resistor, when pot is set to MAX resistance) = 2.34V
(Reading resistor, when pot is set to MIN resistance) = 6.56V <---- **
I don't understand what is going on with the last line. Everything seems to make sense to me until that number goes up! Sorcery I tell you!!!
I was expecting no difference in resistance readings because I thought a resistor is just a static number that it brings current down. Can somebody please explain to me why the pot resistance number goes down, but the resistor resistance is going up when the pot is lowered?
My second question is about Fig 1-58.
It shows what I think is a combined resistance of 4.5V + 4.5V? The picture then shows 9V DC on the '+' and 0V DC on the '-'. Does this mean it's indicating we 'start' with 9V DC, but then because of the resistance it tries to travel through, it 'ends' with 0 DC?
I think what may be causing me all this confusion is I don't really know how resistors work yet, or maybe I'm just missing something else.
Thank you for any help or useful tutorial links you can provide!
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