Home -- Design -- Electronics -- Build -- Notes-- Analysis
All parts were printed on my Prusa MK3s printer. The covers (tops) of the boxes were engraved and cut on my cnc20mm with my new LaserTree 30 Watt laser.
The miniBox was printed out of PETG due to its higher temperature resistance. The rest of the parts were printed out of black, or clear, PLA. The small parts were printed at 0.2mm layer heights in "Quality" mode. The large parts (boxes) were printed at 0.3 layer heights in "Draft" mode.
The tops are engraved into 1/16" Black on White Rotar Engraving Stock (Duets by Gemini) at 1200mm per minute and 18% power, and cut out at 200mm per minute at 95% power.
After 3D printing the parts, and Laser engraving and cutting the tops, we proceed to the assembly and installation stages.
Here are the steps in assembling the miniBox
- super glue the miniBox Lens into the miniBox Cover
- hot glue the miniBox Lens Shield to the miniBox PCB
- epoxy glue the miniBox Base Bottom to the Base Top. Use some 1mm metal wire through the PCB screw holes to align the parts while gluing.
- insert the PCB into the miniBox and secure it with four tiny M1.7x3 self tapping screws
- align the miniBox Cover onto the base and secure it with four M3x5 self tapping screws.
- remove the Cover screws and remove the Cover in prepration for installation
If you haven't already done so, prepare the PCB as follows:
- attach the LCD Mount to the Controller PCB board with three M3x5 self tapping screws *from the back.
- insert the LCD onto the PCB and secure it with three M3x5 self tapping screws from the top.
- place pieces of black electrical tape on each end of the LCD to minimize stray backlight from showing
- epoxy glue the Controller Button Caps onto the PCB buttons
- hot glue the Controller Lens Shield to the Controller PCB
Then you can:
- super glue the Controller Lens into the Controller Cover
- insert the PCB into the Controller Box and secure it with three M3x5 self tapping screws, and one M3x16 machine screw in the upper right corner through the LCD and LCD mount
- align the miniBox cover onto the base and secure it with four M3x5 self tapping screws.
- loosen the Cover screws and remove the Cover in prepration for installation
Before installation you must turn off the inverter main power supply.
We will first install the miniBox and make sure it works correctly Start by making sure the mount is correct.
- Thread four M3x12 self tapping screws into the miniBox Base Bottom until they are protude slightly out on the inside. The ones on the back should protude a bit more. The miniBox should fit snugly atop the inverter
Then prepare the wiring:
- Preprate the power supply Tees and 2A inline fuse
- Attach a Pheonix 2 Pin screw connector to the power supply Tee wires. MAKE SURE THE POLARITY IS CORRECT with the Negative Black on the top, and Positive 12V Red on the bottom, as facing the miniBox,
- Attach a Pheonix 2 Pin screw connector to the power supply Tee wires. MAKE SURE THE POLARITY IS CORRECT with the Negative Black on the top, and Positive 12V Red on the bottom, as facing the miniBox,
- Connect the Custom Blade Connector to the inverter and it's 6 pin JST connector to the miniBox PCB.
- Plug in the two Pheonix Connectors.
- Make sure the Override and Low/High switches are both OFF (in the down position)
- Without attaching the miniBox Cover, slightly tighten the miniBox base screws so that they engage the inverter box and the miniBox is securely attached.
When you are sure everything is correct, turn on the inverter main power supply.
At this point the Green Power LED on the miniBox should come on.
You may now change the Override switch to the ON (Over) position. After a few seconds the Yellow FAN LED should come on, and the Red ERROR LED should NOT BE FLASHING!!.
Congratulations!! This means the compressor is on, and running. You may leave it on until you notice some cooling occuring in the system if you wish.
When you are ready to proceed to the next step, turn the main inverter power supply off.
You may now
- attach the 8 pin miniBox to Controller cable JST connector to the miniBox
- align the miniBox cover and secure it with the four M3x5 self tapping screws.
To install the controller you must first make sure the temperature sensors and all relevant wires are routed correctly to the location where the Controller will be installed.
- insert the Freezer Temperature Sensor into the Freezer a few inches from the top of the insulated compartment and route its wire and connector.
- physically attach the Compressor Temperature Sensor (somehow) to the compressor and route its wire and connector.
- mount the External LED assembly and route it's wire and connector.
- route the Mechanical Thermostat wire and connector.
Plug in all connectors (especially the 6 pin miniBox JST connector and the 2 pin power supply JST connector).
It is beyond the scope of this document to explain the rest of the steps involved with installing, testing, and using the fridgeController in detail. Basically, we will just tell you to ...
- Turn on the inverter power supply
... after which the Controller should boot up and all the relevant LEDs should come on properly. If you have not already done so, you will need to attach the myIOTDevice to the Wifi LAN as a station.
You should now be able to control the compressor from the webUI, via Telnet, from a Serial Monitor over a USB cable, and through the buttons and LCD screen on the Controller. From the WebUI you should be able to see the temperatures, voltages, status, and so on, use the Plotter to see instantaneous changes, and/or use the Chart (Widget) to see the history of the compressor behavior over time.
When everything is working well you may:
- attach the Controller Cover and tighten the cover screws
- mount the Controller with 4 M4x10 wood screws
- provide stress relief for the wiriting
and the system is considered to be officially working!!!
Note: the Controller cover mounting scheme is horrible, requires Cover Clips, and WILL BE REDESIGNED the next time I have to print the Controller Box.
Next: Some various Notes about the fridgeController ...