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Thanks for getting the data quick, now I really can't wait to get mine up and running! Anyway, I was happy with how little tuning I had to do on the model match. Had to tweak heat trans coef as expected. Only surprise was the amount of lag/delay in the system. It took almost 10 seconds for...

Did you use 7gallons?

If you're code is setup to write the sample whenever you see a temp change/power output change then you're good to go (obviously recording the timestamp as well). If you're just sampling at a constant rate of 400ms, in the wost case you could be sampling 1 ms before the sensor updates which...

CSV file is simplest. I can do excel or openoffice as well. Just to clarify... you have the ds18b20 sampling at 400ms, but the arduino is writing values every 100ms to the *.csv correct? Nope, just get things circulating and run it wide open. That will provide a system step response that I...

Good point, lets go with an 11bit A/D (375ms)as a compromise. Should give enough data points during the transient and enough fidelity to curve fit. You still want to sample around the original 100ms rate to minimize as that still adds delays on top of the ds18b20.

Right now I have the RIMS heater and MLT modeled. MLT is just a simple volume of water at same temp (did not try to model stratification) with heat loss from the kettle to ambient. Inputs needed: Kettle height Kettle diameter Flowrate (I’d just time how long it takes to fill 3 gallons...

I'm not an expert in this area but in general....Electrical Noise ( when a conductor is placed in a time-varying electromagnetic field, a cur- rent is induced in that conductor) can cause issues, especially on communication and analog I/O lines. The result could be lost packets, reduced data...

Typically heater life is dependant on thermal cycling. The less it cycles and the smaller the magnitude of cycling the longer the life of the element. My experience with band heaters and may not apply here. Practically speaking your brew setup probably won't run enought to worry about cycling...

I feel like I'm sending you on a wild goose chase :) You don't really need to calculate all you lags unless you're putting a model together. You're probably better off just testing/tuning on the actual hardware. Also are you using a zero cross SSR to control the heating element? You...

Glad that was somewhat helpful... 1st order response can be used as a quick and dirty way to characterize a system in many cases. there are many variables that impact system response to take into account on any given system. Often times several of these factors are negligible. Here's a quick...

Looks like a standard 1st order step response. So basically your stepping up your wattage instantly and all that energy is going into the system. Initially the energy is used to heat the element but there isn't much mass to the element so it heats quickly... as it heats up, more and more heat...

I typically just write the PID control myself and could certainly help out there if you get a sketch started. Probably only need PI (no D derivative) for this loop. Hopefully someone will chime in on the best way to slow down the actuator motor as I'm a lowly mech eng that knows enough elec...

Can you forward some information on the actuator? Its definately not a problem to do feedback control based on temperature. You don't need to know the valve position you're at, but you do need to be able to make small adjustments and hold position. Depending on the actuator you may be able to...

Amazon and ebay have some tri's pretty cheap. Haven't used them yet, I have one on the slow boat making its way here in a couple weeks. http://www.amazon.com/dp/B00OXMHVTO/?tag=skimlinks_replacement-20

I have a similar false bottom which was about 1/4 larger dia than my MLT, I put a small bolt through the center of the FB and attached to my drill. Got the false bottom spinning and ground it on the bench grinder. Wasn't the fastest way to grind but it helped keep everything in round. If nothing...

Great summary ajdelange. As for the terminology of single phase, I agree it should be known as biphase. Unfortunately I've never heard an electrician refer to it as such. As a controls engineer, anything that is phase shifted I consider out of phase. Since the OP indicated that they had...

Here's a mech eng clarification, terminology may be a bit off and feel free to correct any errors.... True statement, NA is "single phase". I'll try to add some clarification since it never made sense to me how hooking 120 to 120 should = 240. Fundamentally hooking up 2 wires with the same...

Nice! Let me know if you want me to run some numbers. Just need your range of supply pressure, burner model, total output (btuh) and prefered turndown in btuh or percent of total output.

I figured I’d share my setup since its slightly different than what I’ve seen others do… I grabbed a couple of asco solenoid valves on the cheap and fitted up my propane hookup to “modulate” my burner (BG12) to run low, medium and high heat settings. In terms of...

I just got my Arduino communicating with my automation direct click plc ( mb rtu rs485) a couple nights ago. I'm sure the DL 06 will have no problem communicating as well. By coincidence I happen to have a DL 05 running my boiler. I used the simple Modbus library that was linked above and got it...