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11. The potential divider

The potential divider is used to give a reduced voltage. It divides in the same ratio as the resistors. They can seem quite complex at first, but they're really not that difficult once you get the hang of them.

There are many formulas relating to the potential divider.

12. Measuring Potential Dividers

Vin (V)

R1

R2

Calculated Vout

Measured Vout

10

4K7 1KO

1.75

1.71

10

2K2 3K3

6

5.77

10

10K 5K6

3.5

3.64

10

3K 1K

3

2.77

12

6K 1K

2

1.77

10

1K59 1K

6.3

6.34

13. Using different voltmeters

 

 

14. The potentiometer

A potentiometer is a variable potential divider. Below is the circuit diagram, & a diagram of its construction. The idea is that you move a slider along a track (it's normally a coil), and depending on the poistion on the coil, the resistance will vary between each side.

 

Presume Vin is set at 10V.

15. The Light Dependent Resistor

The resistance of the LDR (Light Dependent Resistor) falls as the brightness increases.

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