Todd Harrison did a teardown of the CSI Premier 75W and Hakko 936 solder station:
I did the teardown of the CSI 75W solder station as well as the Hakko 936. The Hakko of course had all analog circuits using operational amplifiers and potentiometers as well as a temperature sensor in the iron tip to signal back to a triac chip controller which would trigger the triac to push 24 V AC through the heater in the iron. The CSI 75W was all digitally controlled with an internal microcontroller which was reading the temp sense line and switching the triac on/off through an opto isolator IC. And because it had a microcontroller it was also able to have the programmable set points and programmable sleep and power off timers.
More details at ToddFun.com.
Great stuff, kids!
First he has some problems with his desolder wick holder, than he kills 2 of 8 solder pad, complains about a poorly soldered connector and goes on floundering about the circuit and why it has one populated and one unpopulated controller path and then spirals down into rummaging about the parts and live and all….
100% fun!
To be fair, it can be quite hard to melt the solder blob (especially the modern lead-free type which is the work of the Devil, full stop) on some relatively fat pins without lifting un-attached pads that have nowhere to sink the heat in the process; and if one has problems touching the low-voltage side of a transformer, live or not, one probably should pick some other hobby…
add some regular leaded solder to lower the melting point and make it flow better. Also lots of flux is always a winner!
Don’t use a crummy battery powered iron, retin with 60/40 solder first, flux is your friend, and use a vacuum desolder tool (<$5) not desolder wick. This video was more valuable in showing people how NOT to desolder.