Varying pump speed possible?

[mx]

I'm sure they are DDC-1Plus pumps.

I tried connecting the pumps RPM signal to the miniNG first but the I couldn't get a reading so I connected them to the flow meter ports on the analogue hub instead and that worked fine. Didn't try very hard though.

[masocr79]

hey I contacted mcubed, they confirmed that 1.) you can run two 18W DDCs on a single NG as long as you keep it cool .. and depending on the voltage reduction .. if it gets too hot it will switch to PWM .. and 2.) running a single or dual DDCs on PWM should work no problem .. I thought not from an translated french review that I found which said that that didn't work .. so now I'm not sure .. somebody besides me will have to test it though .. and 3.) they weren't sure about the D5 ..

.. contacted alphacool as well .. they confimred the ultra is the 18W variety ..

so it seems the real benefit is the miniNG can be undervolted both alone and in conjunction with the tban via software configs that get stored in the tban processor ..

now here's a question .. anybody know of a way to overvolt the DDCs to the optimal 13.2 Volts along a similar lines .. using some kind of software and a sendary PSU .. ?

[mx]

mCubed always answears all your questions, they seem to know allot!

Originally Posted by masocr79

now here's a question .. anybody know of a way to overvolt the DDCs to the optimal 13.2 Volts along a similar lines .. using some kind of software and a sendary PSU .. ?

I'm working on it. I have a external 3-15V 40A PSU that's regulated by a potentiometer. My plan is to replace this pot with something that I can control /w the miniNG output. I'm no good at electronics so I'm not sure how to do it.

It's a 10 kOhm potentiometer and it regulates the resitance between three wires, non of them connected to ground and the voltage never exceeds 12V. Zero resitance between the first and second wire means a 3V output. Zero resitance between the second and third wire means 15V output. One alternative is to build some kind of voltage regulated resistor, a digital potentiometer /w 3-12V input and 10 kOhm resistance. Maybe I don't need any circuit between the PSU and miniNG, maybe I only need to replace the pot with the miniNG?

The whole idéa of regulating the input voltage to the DDCs is kinda overkill since their already very quiet. But I don't want to modify my PSU just to control the the pumps, that's just the first step. When I've got it working I plan to regulate my peltiers input voltage /w the same method. This way peltier cooling wouldn't be such a waste of energy and since the TECs wouldn't always be on max voltage I wouldn't always have to run the fans on the rad on full speed to cool them. I've replaced the alu fans with Yate Loon D12SL-12 fans btw, couldn't stand the noice!

It would be nice if I could control the PSU with just on of the miniNGs channels. Then I could get a weaker PSU to power the pumps and regulate it with the miniNGs second channel!

[masocr79]

hey, that is a truly excellent idea .. can you put up a link to that PSU .. i'd like to research your proposed solution in more detail ..

so assuming the miniNG can be rigged to control the pot, you gonna put the miniNG inside the chassis and have it wired to the external PSU .. or put the PSU inside the chassis .. then if you add another external .. dang you'll have to start modding the wall socket next ..

you think they make one with dual pots .. then you could have the pelts on one and the pumps on the other since the pumps don't really need much ..

did you get around to testing those new fans on lowest PWM - didn't see the DC12L-12 on the list of recommended fans at mcubed site .. wondered how they sounded ..

[mx]

Originally Posted by masocr79

hey, that is a truly excellent idea .. can you put up a link to that PSU .. i'd like to research your proposed solution in more detail ..

I brought my MAAS SPS-9400 second hand very cheap.

Originally Posted by masocr79

so assuming the miniNG can be rigged to control the pot, you gonna put the miniNG inside the chassis and have it wired to the external PSU .. or put the PSU inside the chassis .. then if you add another external .. dang you'll have to start modding the wall socket next ..

I'm modifying the PSU to fit inside my chassi. I'm also considering to build a more efficient cooling for the miniNG.

Originally Posted by masocr79

you think they make one with dual pots .. then you could have the pelts on one and the pumps on the other since the pumps don't really need much ..

There certenly exist such a PSU, but it's probably kinda expensive.

Originally Posted by masocr79

did you get around to testing those new fans on lowest PWM - didn't see the DC12L-12 on the list of recommended fans at mcubed site .. wondered how they sounded ..

No I got the fans after I dissassembled my stationary computer. Hopefully I'll have it up and running soon.

[Butcher]

Downside of PWM: Tach output probably won't work (or if it does, it'll most likely give the wrong reading).

mx: a potentiometer is usually used to form a potential divider such that the centre connection can deliver a variable voltage between the voltages on the other two pins.

If the psu and the miniNG have a common ground (likely) you may well be able to just hook the one directly to the other. You may need a pull down resistor or current limiting resistor depending on the configuration of the PSU. Can you post a circuit diagram or pics of the circuit board?

[mx]

Originally Posted by Butcher

If the psu and the miniNG have a common ground (likely) you may well be able to just hook the one directly to the other. You may need a pull down resistor or current limiting resistor depending on the configuration of the PSU. Can you post a circuit diagram or pics of the circuit board?

How can I find out if they have a common ground?

I don't have any circuit diagram but here's a couple of pictures on the potentiometer area. The switch on the back overrides the pot and locks the output voltage to 13.8V.


The last time I tried to figure out how to do this I did some measuring but I didn't really know what to measure.
But non of the three wires seemd to be connected to ground?
Should I take a photo of something else or maybe measure something?

[Butcher]

Common ground - if the PSU ground is connected to the AC line ground they do (since the computer's ground will be).

Kinda difficult to tell what's what there as it appears to be a multilayer board.

BTW, why are you using such a huge PSU for pumps?

[mx]

Originally Posted by Butcher

Common ground - if the PSU ground is connected to the AC line ground they do (since the computer's ground will be).

Kinda difficult to tell what's what there as it appears to be a multilayer board.

BTW, why are you using such a huge PSU for pumps?

I don't think it's a multilayer board, but yeah the photos don't help much.
I wish I had a circuit diagram!

It's my peltier psu. Varying the pumps voltage is just a test, if it works I'll use the same metod for the pelts. I want to vary the TECs voltage to minimize condensation and save some electricity (money). And if I find that varying the pumps speed automatically depending on temperatures is any good I might get a second smaller psu to controll them, it's nice to be able to run them on 13.5V sometimes. But mounted /w anti vibraion rubber things inside my sound dampened case I can barley hear them anyway so I doubt it.

[Butcher]

You could try just connecting the centre wire from pot to the miniNG (or another suitable voltage source if you don't want to risk the miniNG) and see if it can vary the output voltage.