SolarAir Can Controller Hardware

The electronic controller is made with a Raspberry PI, and some electronics on a PCB, and on top a Solid State Relais.

The Raspberry used is a version 2, but it should be exactly the samre with the version B(+) and it can probably be made with a version A as well. Now days the best and cheapest option is probably to use a Raspberry Zero, since it costs less then 10 dollar, and it uses the least power.

In the extra hardware is except some connectors and LED indicators mainly a AC to DC convertor to covert the power from the wall plug to a 5Vdc, and a solid state relais. The 5Vdc is not supplied to the raspberry in the typical way by means of the USB-port, but straight into the pins of the GPIO. The solid state relais used to power on the fan, is not soldered onto the PCB, but mounted on top by means of the screws.

A video explaining the hardware (except the temperature sensors!) is to be found here


The schematic and PCB have been designed with the Eagle PCB software, that is free for hobbyists.

This is the partlist:



Exported from Remote extension cord.sch at 1/5/16 7:57 PM


EAGLE Version 7.1.0 Copyright (c) 1988-2014 CadSoft


Assembly variant: 


Part     Value          Device       Package          Library      Sheet


JP2                     PINHD-2X20   2X20             pinhead      1

K1       351            351          351              relay        1

LED1                    LED5MM       LED5MM           adafruit     1

LED2                    LED5MM       LED5MM           adafruit     1

R1       220            R-EU_0207_15 0207/15          resistor     1

R2       150            R-EU_0207_15 0207/15          resistor     1

SJ1                     SJW          SJW              jumper       1

T1       BC547          BC547        TO92             transistor   1

U$1      RAC05-05SC     RAC05-05SC   RECOM_RAC05-05SC janlib       1

X1                      W237-103     W237-103         con-wago-500 1

X2                      W237-103     W237-103         con-wago-500 1

X3                      W237-4       W237-4           con-wago-500 1


X4                      W237-103     W237-103         con-wago-500 1

Here the schematic;

The schematic in Eagle 

Below the PCB design

The schematic in Eagle Schematic designer


If you then stack this PCB on top of the raspberry, and put the Solid State relais on top, tis is how it looks;

 This is how it is built in: