ELECTRONICS Input Devices Flashcards
What is a microphone and give energy transformations
Amplifies sound. Sound to electrical.
Give examples of input devices
Microphone, thermocouple, solar cell
What is a thermocouple and give energy transformations
Heat to elecrical
What is a solar celland give energy transformations
Light to electoral
What is a thermistor?
Changes resistance depending on input factors (is also an input device)
What happens to resist ace depending on temperature using a thermistor?
Temperature Up Resistance Down
What is an LDR?
An input device which varies resistance depending on input factors.
What happens to resistance depending on light with a LDR.
Light Up Resistance Down
What is a capacitor?
Pa device which can sites electric charge
What are the units of capacitance?
Farads
What is the voltage of a fully charged capacitor?
Equal to the supply voltage
What suitable input device is always used in a time delay circuit?
Capacitor and resistor
What is a potentiometer?
An input device that can change resistance (sliding) moved up resistance increases across bottom letter and decreases with too.
What is a voltage devider?
Two devises (usually resistors) connected in series. The voltage is divided up into two smaller voltages.
Equations to remember with voltage devider a
V1. =. R1. V1= R1. x Vs
—— ——– ———–
V2. R2. R1 + R2.
And Vs= V1+ V2
For this circuit the resistance of the LDR decreases as more light falls so voltage across LDR (v1) _______ and the voltage across the resistor (v2) _______even though resistance stays the same.
For this circuit the resistance of the LDR decreases as mor slight falls so voltage across LDR (v1) decreases and the voltage across the resistor (v2) increases even though resistance stays the same.
Why are capacitors connected in series with a resistor?
Allows time for capacitor to charge up to supply voltage so time can be controlled.
What are rules with voltage dividers?
As resistance decreases across one component, so will its voltage so voltage of other component will increase.
How would a capacitor be discharged?
By closing the switch.
How would you increase time for capacitor to charge?
Increase resistance of resistor or increase value of capacitor.
GO LOOK AT SHEETS ON VOLTAGE DIVIDERS
GO NOOOOOOOOOW
