Trip the switch fan-tastic

By the time I’d finished soldering up my temperature switch last Sunday it was too late to install it in the greenhouse, or even test it.

This weekend it was time to test the switch. Imagine my surprise when the red LED on the switch came on when I connected the battery to it for the first time! It’s hard to see in this photograph but the red LED really is on…

The red LED glows showing that the switch has power

However, the next stage was much harder. I have to confess I had no idea how to wire up the fan to the switch so that it was being controlled by the temperature sensor. Fortunately my dad did and, after a quick phone call, I’d hooked up the switch and the fan and the power was flowing. Thanks dad!

I then set about fitting the switch into a sealed box to protect it in the greenhouse. This meant filing down the circuit board and cutting two holes in the box so the temperature sensor could stick out and I could also see the LED. The temperature sensor is clearly visible to the bottom right of this picture:

Temperature switch in the sealed box

The box was then closed and the fan and switch installed in the roof of the greenhouse. It was a nice day and the temperature was up around 20°C in the greenhouse. Here’s the fan in action:

Fan and switch in action

Now we have to wait to see if the heatsink makes a difference…