So at long last I have received my replacement AD597 thermocouple conditioner ICs and I set out to create the breakout board to fault find what went wrong previously.
The circuit diagram looks like this:
and I have created a pdf to print out with a lot of these on, so if you want to make your own SOIC8 to DIP breakout board then just download the pdf by clicking on the SOIC8 to Dip – multiple between the brackets (SOIC8 to DIP – Mutliple) and print it out and then there you go. Update, I’ve also shared the Eagle Files on my Github account, so if you want to download it you can get it from here.
So First things first, I use the toner transfer method to make my boards, so I start out with a nice hot iron and ironed my circuit:
When my boards were nice and toasty I took them off, the boards were a bit hot so they weren’t to happy 😉
Once in the bowl and ready for water, the boards were OK.
So I soaked my boards for about 10 minutes and then removed it and the paper to get it ready for edging. I should first have drilled all my holes since I prefer to drill first before edging so that you don’t run the risk of ripping of connection pads. Obviously you will need to have everything ready before you can start, a work surface, protective cloves, acid and some concentration juice (green bottle 🙂 )
After edging were done the boards came out pretty nice and looked like this:
I then went ahead and drilled my holes and luckily I didn’t damage any of the mounting pads.
So now the boards were ready and I could remove the ink with some thinners or acetone.
OooooOO nice and shiny. I only needed one but I had these scrap pieces of board lying around so I created a few for future use. So after completion of the boards it was time to hit the soldering station.
The board came out pretty good, I worked carefully at temperatures that weren’t too high so that I wouldn’t overheat the AD597. Most importantly, it fits into my breadboard so that I could prototype. All in all a good success.
After I completed the test breakout board I went through the AD597 datasheet again to try and figure out whether I designed my circuit wrong but I didn’t so I went ahead and rebuilt the circuit diagram as I had it and started testing it.
Looks nice and best of all is that it was working. I discovered that if your thermocouple is not connected in the correct way (Correct metal on the correct input) then your AD597 output voltage will drop as temperature increases and not increase proportional to the temperature that is also increasing. I will be playing around further to make sure that my programming is correct so that I can get the correct temperature each and every time no matter what the temperature. once I have further feedback I will update you guys again.