Sharing Flashcards
1
Q
What are the properties of a potential divider circuit?
A
- Some potential divider circuit have fixed resistors.
- Some potential divider circuit have one variable resistor.
- The voltage can be altered.
2
Q
What is output voltage?
A
The output voltage is a fixed proportion of the of the supply voltage.
3
Q
V out Eq.
A
4
Q
When R2 is much larger than R1
A
V out ≈ Vin
5
Q
When R2 is much less than R1
A
V out ≈ 0
6
Q
Threshold voltage
A
- Some electronic components will start working at a threshhold voltage.
- Using a variable resistor as one part of the potential divider allows the threshold voltage to be set.
7
Q
Resistors in parallel
A
Resistors can be arranged in parallel and this will decrease the total resistance.
8
Q
Eq. for resistors in parallel
A
9
Q
Resistance of light-dependent resistor
A
The resistance of a LDR decreases as the light intensity increases.
10
Q
Resistance of thermistor
A
The resistance of a thermistor decreases as the temperature increases.
11
Q
How are potential divider circuits used?
A
- Street lights have LDRs in potential divider circuit.
- When it is dark, the resistance of the LDR is high, the output voltage is high and switches on the street light.
- A thermistor can be used to switch on a heater when the temperature gets too low.
