A few days ago, the shipment from futurlec with my electronic components finally arrived. It took them almost a full month to get shipped and arrive here. Inside the envelope there were a lot of separate plastic bags, all labeled with what was inside. That's convenient.
I've worked on this all morning, so I was hoping it would work. But it didn't. The voltage to set the desired temperature only goes up to 60mv. So the thermostat can only regulate temperatures up to 6°C. On the positive side: the led goes on for about 2 seconds before turning off, so I think the hysteresis is working, but it never gets cold enough again to make it go back on once it goes off.
I started measuring if all the resistors were correct and found that the potentiometer is 5k instead of the 2k I ordered. All the other ones were correct. I bought the 2k one because futurlec didn't sell 2.2k. I had already send them an email about the broken multimeter and didn't want to send an other one for something worth less than 1€ so I just ordered a 2.2k potentiometer from ebay. I hope everything will work with the correct potentiometer installed. Below I've added a picture of my thermostat. The broken corner is my fault, I dropped the board while I was unpacking it. Luckily its only a small corner that went away, and the rest is intact.
And while I'm talking about electronics, I might as well mention that I'm still waiting for everything from mendel-parts to be shipped. The electronics have arrived in their shop, but my order hasn't been shipped yet. I suppose sending 50 order in one day is a little too much for them. I couldn't do that either.I hope everything will arrive before next weekend, so I can finally start building my Mendel.