Download Voltage Divider

Voltage Divider
1
Series Circuits
• Take a series circuit with two resistors
• Since each is the same resistance, they use up the same
amount of voltage, 6V
• Therefore the voltage at point A is 6V
2
Series Circuit
• We can rearrange the circuit
as shown on the right
3
Series Circuit
• And then simplify it once
more
4
Series Circuit
=
5
Voltage Divider
• It doesn’t matter the amount
of resistance, if they are equal
they use the same voltage
• The voltage at A in this case is
still 6V
6
Voltage Divider
• By adjusting the ratio of the
resistors, we change how
much voltage each one “uses
up”
• The resistance at A is
significantly higher now since
the second resistor will need
much more voltage
7
Voltage Divider
• The resistance at A will now
be significantly lower since
the first resistor will use up
most of the voltage
• By altering the ratio of
resistors we can alter the
voltage at A
8
Voltage Divider
• Suppose we replace the top
resistor with a sensor that can
change resistance
• In this case a light sensor,
photoresistor, that operates
from 1k – 10k based on light
• By measuring the voltage at A
we can determine the amount
of light in the room
9
LAB
Complete the “Sensors in a Circuit” Lab
In Unit 10
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