• Electrical parts box, including the following:
  • Spare bulbs and holders,
  • Spare LEDs,
  • Spare resistors (at least two different values),
  • Spare photoresistors, and
  • Spare pressure resistors.
• Extra spare parts, especially the following:
  • Multimeters
  • 50 V power supplies
  • Breadboards
  • Alligator clips (for pressure resistors)
  • Masses (for pressure resistors)
  • Slide-wire potentiometer
• Fuse repair kit, including the following:
  • Extra batteries (AAA)
  • Extra fuses (500 mA or 630 mA)
  • Philips screwdriver (medium-size)
  • Flathead screwdriver (small-size)

• 2 multimeters
• 50 V power supply
• Breadboard
• Slide-wire potentiometer
• Electrical parts:
  • Incandescent bulb (in holder),
  • LED (on board with resistor),
  • 2 resistors (preferably of two different values),
  • Photoresistor,
  • Pressure resistor (with alligator clips), and
  • ~4 masses (for use with pressure resistor)

On the 50 V/2A power supplies…

• …turn the current limit up to max (2 A), and
• …check the overload button (and reset if necessary).

Check the multimeters to make sure there aren't blown 500 mA fuses (on the mA and $\mu$A settings).