Electronics Flashcards
What is battery capacity measured in?
milliamp-hours
How do you find the capacity of a battery?
battery capacity (mAh) = current (mA) x time (h)
What sensors are used to measure force?
Load cell
Force sensitive resistor
What sensor is used to measure light?
LDR
What sensors are used to measure temperature?
Thermistor
Analogue sensing IC
Digital temperature sensor
What sensor is used to measure sound?
Microphone
What sensor is used to measure infra-red?
IR sensor (infrared)
PIR sensor (passive infrared)
Photodiode
What sensors are used to measure position/distance?
Switch
Hall effect sensor
Proximity sensor
Reflective/slotted opto-switch
Potentiometer
Rangefinder sensor
What sensors are used to measure rotation?
Reflective/slotted opto-switch
Gear tooth sensor
Quadrature rotation sensor
What sensors are used to measure angle?
Potentiometer
Angle sensor
Accelerometer
What are the 4 different ways to interface sensors on a microcontroller?
Digital switch sensor - Open/Close switch for a quantity
Analogue resistive sensors - Uses resistance to measure the quantity
Analogue/digital output sensor - Direct digital or analogue output voltage
Data stream output sensor - Transfers alphanumeric information to microcontroller rather than a voltage
What are the outputs from a microcontroller?
Light
Sound
Motion
Information
What are the types of actuators and what motion do they provide?
Solenoid - Short reciprocating
DC motor - High speed rotary
Servo motor - Oscillating
Stepper motor - Rotary, step by step so not smooth
Brushless motor - High speed high torque rotary
Piezo actuator - Very short reciprocating
What is an ADC?
An analogue-to-digital converter converts an analogue voltage to a digital value.
Why is it sometimes necessary to amplify a signal?
Some sensors produce very small signals that would limit the ADC so sometimes an amplifier is used to amplify the signal to get a good range of output values from the ADC.
