For those who are interested in soldering iron temperature control I have posted a video and a blog post with complete details on how to modify an ordinary plugin soldering iron to work with a digital temperature controller. A thermocouple was mounted internally inside the soldering iron so it is out of the way. The idea was to find the "sweet spot" at the back of the heating unit inside the soldering iron where the temperature would match up with the temperature of the soldering iron tip.
The unit was tested on a range of temperatures at 200°C, 250°C, 300°C and 350°C to see if the tip temperature would coincide with the internal temperature as the soldering iron heated up. The results were encouraging. The tip temperature varied by only a few degrees in most cases and even coincided with the internal temperature a few times.
I also have a short video without any narration showing how to adjust the thermocouple to the tip temperature.
A PID controller was used for the test but it was slow. I am looking for a better controller that will achieve the temperature settings faster. For anyone who has some ideas on this please post your comments.
After 24 hours if the new topic is approved, I will post the links to the videos and the blog post.
Hey,
I am new here and this is the first topic that I comment. I am too trying to build a controller for cheap soldering iron that run from 110V. But I'd like it to be as generic as possible, because I will use a similar controller for a toaster reflow oven (that will also be used to dry UV sensitive paint).
I will prototype with an arduino or a freedom board and will embbed the final circuit, so the controller should be digital.
I am waiting for my thermocouples to arrive from china (should take a month or two), so far I've taken the soldering iron apart and seen that the thermocouple fits inside so I can keep it hidden, however it will measure the bottom of the iron, not the soldering tip itself (so far).
Could you please upload the links?
Also, I have a question - what is the advantage of soldering irons running on 24v, are the heating elements better?
Regards,
John
I would like to build a similar 110v controller also. The thermocouple location in the back of the heater should work okay.
I had the exact same question re: soldering irons running on 24v. My guess is that the same voltage can run the both the heater and the electronics. The circuitry needs to step down the AC line voltage only once. 24v is also common with home heating and air conditioning (HVAC). 24v powers thermostats, relays and other controls.
Here are the links:
Soldering Iron PID Temperature Controller:
https://www.youtube.com/watch?v=uPF152qa5rU (https://www.youtube.com/watch?v=uPF152qa5rU)
Blog post with details:
https://pcbsmoke.wordpress.com/2015/04/ ... ontroller/ (https://pcbsmoke.wordpress.com/2015/04/21/soldering-iron-pid-temperature-controller/)
Follow up video on adjusting the thermocouple:
https://www.youtube.com/watch?v=9_SoB_bUq2M (https://www.youtube.com/watch?v=9_SoB_bUq2M)