🧠

course electronics

Intro to Physical Computing

Electricity basics

  • Electricity
    • Flow of electrical energy through conductive materials
  • Electrical circuit
    • Power source + components that convert electrical energy into other forms of energy
  • Sensors
    • Components that convert other forms of energy into electrical energy so they can be read
    • Switches, knobs, light, motion sensors, etc.
  • Actuators
    • Components that convert electrical energy into other forms
    • Light bulbs, motors, LEDs, heaters, etc.
  • Transduction
    • Process of changing one form of energy into another
    • Transducers are devices that do this
  • Voltage
  • electric current
  • Resistance
  • Ground
    • The place in the circuit where potential energy of electrons is zero

Voltage <> Current <> Resistance

  • Imagine an avalanche of snow on a mountain
    • Height of mountain --> voltage
      • The higher it is, the more potential falling material has
    • Amount of snow/rocks --> current
    • Steepness of the mountain --> resistance
      • Steeper --> less it will resist the flow of snow/rocks
  • Volts = Amps x Ohms
    • $V = I \times R$
  • Watts = Volts x Amps
    • $P = V \times I$

Components

  • Conductors
    • Materials where electrical current moves freely
  • Insulators
    • Materials which prevent the flow of electricity
  • Resistors
    • Resist but don't totally block flow of electricity
    • Used to control flow of current
      • Current can flow either way through a resistor
    • Types of resistors
      • Thermistors
        • Change resistance in reaction to temperature
      • Photoresistors
        • Change resistance in reaction to light
      • Flex sensors
        • Change resistance in reaction to being bent/flexed
      • Force sensing resistors
        • Change resistance in reaction to force placed on them
    • Divide voltage when in series
    • Divide amperage when in parallel
  • Capacitors
    • Store electricity while current is flowing into them
    • Release energy when incoming current is removed
    • Measured by their capacitance in Farads (or microfarads)
    • Can be polarized so current can only flow through them in one direction
      • Wiring these backwards can damage the capacitor and your circuit
    • Will explode if more voltage is applied than what they are rated for
  • Diodes
    • Permit the flow of electricity in one direction, block in the other direction
  • Transistors
    • Electrical switching devices

Backlinks

Course