The combo, Kill-A-Watt meter --> Auber DSPR1 power regulator with solid state relay --> Auber SYL-1512A PID or ON/OFF or Limit controller with mechanical relay and K thermocouple --> heater of a water distiller works fine. Smoother and more precise power regulation (watts) than with the Variac combo, but lacks the ability to 30% over volt available with the Variac.
It occurs to me that if you wired the temp controller and rotary encoder power controller as a single unit you could eliminate the mechanical relay. One of the wires from the power controller leading to the solid state relay is run through the internal relay contacts of the temp controller.
I see Lab Society has a controller with a dial reading % power regulation and PID control, $1,300:
When you dial in the power (watts) you don’t need full PID function, ON/OFF works just fine without over/undershoot.
The Auber DSPR400 (DSPR220 with two relays) that I started this thread about is still far superior, I’m rewiring it to support at least one of the internal relays to make it even more versatile, basically I’m adding an ON/OFF function upper set point, which would be on point if I was running a SPD setup… The relays are configurable for almost anything you can imagine possible, and I haven’t even thought about utilizing the timer functions yet. Edit: I assumed the distillation phase end set point could be used to activate the relays, I just read and reread the manual and can’t find that specific option. Imo, this is still the best distillation controller available (outside of an industrial controller that would require Einstein to program and use.)
From the above post: “The Auber DSPR400 (DSPR220 with two relays) that I started this thread about is still far superior, I’m rewiring it to support at least one of the internal relays to make it even more versatile, basically I’m adding an ON/OFF function upper set point, which would be on point if I was running a SPD setup… The relays are configurable for almost anything you can imagine possible, and I haven’t even thought about utilizing the timer functions yet. Edit: I assumed the distillation phase end set point could be used to activate the relays, I just read and reread the manual and can’t find that specific option. Imo, this is still the best distillation controller available (outside of an industrial controller that would require Einstein to program and use.)”
I went through the manual many more times yesterday, and did some experiments this morning with an ohm meter connected to a relay output, and found I I had confused myself, lol. I just finished the rewire and testing, and it works as I had originally hoped providing ON/OFF control at any set point I choose hand in hand with the power regulation function. The trick I came up with to lock a set temp with power regulation on either side of it is still the slickest thing imaginable, but I like options.
I wired the two relays in series with one of the leads to the solid state relay, either one or both can be programed to interrupt the power when and how I want it. Now if I just had a SPD setup to play with (and a new work space, I’m getting the boot the first of the year.) Anyone need a part time lab tech in SoCal, preferably near the coast??)
Sensors: (as the Auber DRSP220 & DRSP400 only accept RTD/PT100 input, and I included in this thread how to wire a rotary encoder power controller in combo with a PID or ON/OFF or Limit controller with a standard K thermocouple input)
First a couple of insightful posts from Beaker,
"I was an electrician on F4 Phantom jets whilst an active Marine. At least for a while. Thermocouples and a whole slew of other sensor types are an electricians responsibility. Oddly the final plug to be hooked to a detachable tactical nuclear weapon for which the Cold War Phantom was designed to carry was not the responsibility of Ordanance but the duty fell to the electricians. A somber moment indeed stepping back from a idling Phantom and giving the thumbs up on that one being ready to go… I will limit the discussion to thermocouples here…
Thermocouple is short for thermocouple pair. It simply means two wires of different metals twisted together at one end and left open at the other end of the pair to connect to a meter. When any two dissimilar metals are in physical contact with each other there is a difference of electrical energy potential between the two metals. As I recall the reason two metals do this was deemed by my Marine Corps instructor to be caused by FM (effing magic) and left it at that when asked.
The charge carried by the metal is directly related to the temperature of it in a linear fashion. When it gets hotter the charge is greater than when it is cooler. The metals will increase their charge they naturally hold (FM) but at different rates from one another as they get hotter. The difference of electrical potential is then measurable by a pretty simple circuit. The terms “voltage” and “difference in electrical potential” are 100% interchangeable.
The type of thermocouple like K just defines what two types of metal wire are twisted together so then a known circuit can be employed. Alumel and chromel were used I believe for a lot stuff like this. My point in explaining all this is that a “thermocouple” is maybe encased in something and maybe has a special plug at the open end but it is simply two dissimilar wires twisted together at the hot end.
When my thermocouples go bad because I bend them around or spill on the junction and such I have no problem at all chopping off the end and stripping and twisting the wires together. Presto. Thermocouple fixed lolz. The twisted wires will corrode at the junction and in fact rust is a direct result of two dissimilar metals in contact with each other but in the form of intergranular metal contamination contact that is unavoidable. Most often chopping off the end of thermocouple pairs and twisting them back will “fix” the pair of wires.
I can tape my thermocouple pair twisted like that to the outside glass at any point in my rig with aluminum heat tape from 3M but normally now just poke the wires between the mantle and the glass.
Do we get paid by the word on this blog?
NOTE: The metal shielding you see on thermocouples can cause hella big headaches and imo are for show only…ducking now… tomatoes fly overhead…
What that shielding actually does in reality is provide multiple opportunities for the worst of the worst of electrical trouble shooting nightmares called simply “ground loops” . I know how to wire to avoid ground loops but as a rule stripping that crap off is precisely what I would do for a fixed permanent install instead of my cobbed up protype lol."
"My PID Control works best to hit target temp when I place the thermocouple sensor between the glass boiling vessel and the heating mantle at the midpoint of the boiling puddle sort of on the side. For me PID sensors in any PID application work best when they are closest to the source of power being controlled (the mantle itself). The algorithms used seem to predict things more accurately that way. For a horizontal run I place a thermocouple on the top of the glass at the neck too during the boil that is hooked to my yellow meter. The mantle controls the heat but the one at the neck tells me when cannabinoid will begin showing up in the first bulb. At ¾ of one micron when that top glass temp at the neck reaches about 132C I can see cannabinoid as a thick resinous material accumulating in the flask neck toward the exit into the bulb. At 140C it runs pretty fast and using time lapse on my iPad it looks awesome lolz. Running hotter makes it immediately darker.
Dialing this in is pretty easy when the probe is just outside the glass and between the mantle. I have tried other places but my PID Control has an overtemp feature to prevent mantle damage so the sensor must be in contact with the mantle for this to work."
I agree with everything Beaker’s saying, but there are many K thermocouple choices not found at eBay that might be slicker if you have the money and time for experimentation, here is but one from Omega,
“OMEGA offers a line of butt- welded bare wire thermocouples that provide a faster response time and can be used in tighter spaces than standard beaded wire thermocouples.”
A pot of coffee and a search of K thermocouples at Omega will overwhelm you.
Same goes for RTD/PT100 sensors, eBay has nothing compared to Omega. Of the many choices, what caught my interest is the thin film elements (it’s just the element and a couple short bare leads, you need to make up the rest of the sensor assembly yourself,) only $50 for five.