Freezer to Refrigerator Conversion/Manufacturing Instructions

From Open Source Ecology
Jump to: navigation, search

Safety Check

  • Goggles

Tool Check

  • drill
  • stepped drill bit
  • crimp tool
  • wire cutter
  • small blade screw driver
  • phillips screw driver


Inventory Check



Step by Step


1. drill holes

  • measure the diameter of the extension cord that will be used.
  • using a stepped drill bit, cut two holes on opposite sides of the box.
    • centered about 1"inch below edge of box
  • drill a 5/32 hole for the thermister signal wire

2. place and cut wires

  • cut extension cord for desired lengths. in half is fine.
  • run about 8 inches of cord into holes.
  • tie cord in a knot. pull knot firmly against the side of the box.
  • strip off shielding, leaving about half an inch past knot.

3. fit check

  • place the wall wart, relay switch and microcontroller into box.
  • confirm that the usb cable can reach the microcontroller.
  • using double sided stick strip, attach relay in place
  • wrap electrical tape around male pins out of bottom of arduino if necesaary

4. crimp connections

  • study the wiring harness diagram
  • start with the AC extension cord wires.
    • fit check the wires into place, then cut as needed.
  • crimp ends as noted in diagram
  • crimp green AC ground wires back togther
  • cut thermister wire to length
    • insert through its box hole
    • tie knot inside box and pull tight against box wall
  • crimp jumper wires as noted in diagram
    • wrap resistor and adjoining connections in electrical tape
  • fold back ends of thermister lead wires
    • crimp each end into a fully insulated male connector
    • wrap both connectors together with electrical tape
    • wrap exposed lead wires from thermister leaving only the tip exposed
  • crimp female connectors to thermister wire

5. install connections

  • connect AC lines to relay screw terminals. look for the squigly line symbol (~).
  • using a small blade screw driver, expand the yellow female connectors slightly
  • slide yellow connectors on to the wall wart. polarity does not matter.
  • connect the jumper wires with connector ends to the relay
    • green wire to (-). red wire to (+).
  • solder female headers onto microcontroller if not pre-installed how to solder
  • confirm that the arduino code has been uploaded how to upload
  • review the microcontroller jumper connections on the wiring diagram
    • connect the usb cable
    • connect the jumper wires as seen in the diagram
    • then put the microcontroller in place in the box next to relay

6. test and finish

  • connect an AC device to the plug (a wall clock is easy)
  • plug into the wall
  • confirm the microcontroller led is on
  • confirm AC device is powered on
  • place thermister into a freezer
  • the AC power should turn off
    • this verifies basic function
  • feel free to tweak arduino code trigger values as desired
  • screw on the PVC box's lid.
  • install on chest freezer, you now have a chest refrigerator