Day 2


  • Motors are really wild and can cause as many headaches as they can bring joy.
  • Motors work through a process of induction. When you put energy through a wire or conductor, it creates a magnetic field around the wire. The direction of the current is related to the direction of the field.
  • magnets near the field will be attracted or repelled depending on their orientation. A shaft with magnets on it, surrounded by a magnetic field, will spin on its axis.
  • This works in reverse as well. if you spin some magnets near a wire, they will induce a current.
  • Voltage ratings for motors are when they work at their peak efficiency. less voltage will slow the motor down, excess will speed it up (NB these will reduce the life of a motor)
  • Motors draw the most current when under load, that is, when they are moving something, or staring up and overcoming inertia.
  • a motor’s speed is measured in RPM
  • Torque is a measure of how much a motor can pull a weight attached to its center rod.
  • Brushed Motors – older, less efficient
    • Simplified external wiring – can be wired directly to DC power and control can be a simple as a switch.
    • Brushes inside electric motors are used to deliver current to the motor windings through commutator contacts.
    • brushes wear out over time
  • Brushless motors – newer (hello 1960s technologies!), sexier
    • longer lifespan, no components to wear out
    • require additional devices for control
    • magnets are located on rotor (shaft), the coils on the outside
  • geared motors
    • reduced speed, but increased torque
    • friction means that parts may need to be replaced
    • more current may needed to overcome intertia
  • Stepper motors
    • DC motors that move in discrete “steps”
    • often found in printers, plotters and the like, allow for movement to specific spot along the motor’s path.
    • require a fair amount of external circuitry and control systems
  • Servo motors
    • a specific kind of geared motor that has circuitry inside it to control position


  • PCBs, printed circuit boards are used for manufacturing circuits in a more stable way than the point-to-point wiring used in a breadboard.

Through-Hole Soldering

  • Through-Hole Soldering
  • Soldering is used to stabilize and repair components of a circuit. Through-Hole soldering is applied when using through-hole components, which we will use in this class, and which are larger and can be used with breadboards.


  • Integrated circuits: small components that contain entire circuits with specific functions (logic gates, timers, amplifiers) that are used ubiquitously across different electronic systems.
  • The 555 timer is a great ‘starter’ IC
  • The LM-386 is amplifier IC that we will use in constructing a CrackleBox