i wouldn't call this an issue so much as a design choice...likely koolance did it to try and encourage sales of thier own temp probes...my bitspower probe still works when attatched..it just seems to have a static temperature delta. But it moves up and down a degree or so at a time so it seems to be functioning, i just have no way to verify the demp delta or accuracy. When the new controller arrives maybe i will try and plug them all in together and see if i can figure out the exact delta and/or if the probe is still behaving correctly. At first glance, this seems to be something that should be adjustable on the software side, similar to how you can adjust the flowmeter readings based on tubing diameter. Perhaps adding calibration for different OHM probes will come in a future update?
To me its not that much of a biggy because i have both bitspower and koolance probes...but I am sure others would like to avoid purchasing koolance ones. Really though were talking a savings of 40 bucks on a dual loop system which would likely cost hundreds of dollars to begin with...i can only really see the need for more than two coolant probes for testing/review purposes. In a live loop adding tlines etc for every probe location would get messy, and possibly add restrictions. I mean whats the practical use of knowing your temps after every block unless you doing a review, or perhaps a test to see how flowrate affects temps in a series loop.
For me i just want to know my delta above ambient right after the rad.
unfortunately I dont have any 3.2(5) only DDC 2's. i also thought of trying the pump on a fan channel but I am scared to attach the DDC2 to the PWM control because i have read threads in which alot of on off cycles is what can kills the DDC2. My first thought is that it *should* work fine though, the controller doesnt care what it is powering as long as you don't exceed the channel limits.
As far as minimum voltage goes, i made another post here: http://www.xtremesystems.org/forums/...d.php?t=225786 and it seems the entire DDC pump family has an operating range of 8-12V, with PWM you should theoretically be able to take the pump to a lower speed than analog because you are giving constant bursts of 12V... The lowest my DDC2 will spin is at 7.92V on analog on an empty loop I believe, but only if it gets an initial ~8.25V initial spin..which the controller does provide on startup. So constant PWM bursts of 12v should be able to take the rpm down quite low...at least if the pump was running dry. PWM on fans is great because the blade momentum keeps the illusion of constant spin, but there isnt really alot of momentum happening on the impeller when submerged in liquid. When you cut the juice, it pretty much stops..so the lower the RPM you try to achieve, the harder it will become to maintain a steady flow. Also, at about 8V in a loop with just a HK 3.0 i was getting around 1.5 GPM, I guess some people might like to take it down to the 1 GPM threshold but much slower than that I don't know if it would be practical. For me, if my flow sinks much lower than 1.5 I would probably add another pump, especially with multiple blocks in series so the heat pickup doesnt get amplified.
Another thing i do notice about my DDC2 is that even when plugged into a straight molex there is about a 1 second lag from the time voltage hits it until the pump actually spins, I don't know if 3.2 series does this.
So on the DDC2 series I don't think running it off the fan channel would work....because the PWM switching would be far faster than this 1 second lag....which may be why they used analog control on the pump channels in the first place. If the 3.2 does this as well then i would guess PWM would not be a viable alternative for controlling this series of pump either.
My suggestion to you or anyone else out there using a 3.2(5) is to plug it into a PWM controller and see what happens. (not in a live loop though) If rpms adjust as expected...great! But be warned, alot of on off switching is a suspected cause of failure in the DDC2 series..and PWM control is on off like crazy, in one day you would easily exceed the average on off cycles compared to a life time of normal usage. The PWM control on the TMS-200 is phenominal it really is very nice..so if your pump works with a different PWM controller im sure it will work with the TMS.
I am curious as to what kind of loop you have setup with 2 pumps full bore, and a 3rd being modulated....is it somehow providing extra pressure to one side of the loop or the other? That would be cool..
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