Laing DDC pump repair PCB mod

[mochti01]

I'd also like to better understand the variable resistor deal between VSP and Vref. What sort of variable resistor should go between these?

You have to cut the connection between VSP and Vref. Than you can put a resistor between it. Or you use a 47K poti to regulate the little monster.

[lowfat]

Those numbers are insane! I most definitely will be trying to fix these two extra DDC's once those pre-soldered PCB's come back in stock. As for going above 12V, I do believe the TB6588FG lists a max of 2.5A. Although if you feel like being the Guinea pig to see if they'll last above that much juice and by how long, feel free.

[SpuTnicK]

It is pushing upwards of 2.5 amps with just 12V though and I am a bit paranoid about heat.

i bet every is paranoid about the noise level at that performance, not to mention the consumption rate - almost 30W - hello Lamprtron FC5V2
Heat wise, try attaching a temp sensor to IC case.

Can you make a video of the pump running at 2.5A?

[xcooling]

use a 100Kohm variable resistor.. it allows u to control the speed of the pump.

On the mcp355, the controller will overheat if u don't do this.

[mochti01]

It will not overheat... I left it 24h to run on 100% in my system and nothing happend. With 50Kohm the pump will not start. 47Kohm varibale resistor is perfect.

[mochti01]

50V would be impossible because the maximum current is 2.5A and on 12V it takes 2.1A. So you can imagine whats gonna happening on 50V or?

[mochti01]

I had two of them with a watercool duallaing top. Two MCP355 made 190l/h in my very restrictive system and two diyinhk 3.2 on 100% with 12V made 300l/h.

[glide 1]

Success!!!

Here are the 2 pumps i'm working with:



used the pre soldered 18w pcb for this and followed this diagram - http://hostthenpost.org/uploads/15ad...8d62155880.jpg

pump works fine and seems to move a lot more water than a stock MCP355. only problem is that the case gets a little hot to the touch after a few minutes. i doubt it can stand sustained use like this. Will look into the vref, VSP mod to slow motor a bit or maybe a pot - just want to make sure what values to use.





used the 10w pcb for this. no problems except that the pump pulsates after about 10sec. then eventually stops. if i restrict the outlet side with my finger (simulating cpu block, rad restriction hahaha) then it is ok and runs very smooth and quiet. flow is also better than stock ( as far as i remember). i think once this is in an actual working loop, it will do ok.

These were all very quick, non scientific tests obviously. i just wanted to see if i could get the pumps working.

Big thanks to all who have contributed to this thread, much appreciated.

[lowfat]

Tried once more to get my blue prop DDC to work. My solder joints are considerably better and I heat shrink all of the extensions. Still unable to get it to work though, it doesn't vibrate as before though. I can hear a clicking sound coming from it, but that is it.

[Martinm210]

Martinm210: and how noise subjectively seems with that high rpms relative to common DDCs/D5s?
As for heat, imho no need for much worries. Weren't fets that overheated most on stock DDC PCB?

Subjectively I think the Toshiba controller is a bit more buzzy than the DDC3 motor controller, but better than the DDC1 motor controller. Hard to tell though with the different RPM values.

You have to cut the connection between VSP and Vref. Than you can put a resistor between it. Or you use a 47K poti to regulate the little monster.

Thanks! I'll see if I can round one of those up at radio shack. I have some larger ones, but I'd like to have a nice small one I can mount to the pump case.

i bet every is paranoid about the noise level at that performance, not to mention the consumption rate - almost 30W - hello Lamprtron FC5V2
Heat wise, try attaching a temp sensor to IC case.

Can you make a video of the pump running at 2.5A?

Yeah, I'll work on a video comparison as part of my blog, but I'll wait until I test the Sanyo flavor as well so I can get both done in the same noise test session. It might not be until next weekend though...it's about the only time I can do good noise testing in the wee hours.

It will not overheat... I left it 24h to run on 100% in my system and nothing happend.

My motor has a metal plate on the bottom and I measured roughly 53C max on the metal plate. If TJmax is 150C, it's probably still within operating range.

The Toshiba controller spec manual says it also has thermal protection. At 165C it'll shut down and turn back on at 150C.

Supposedly the plastic can melt at 170C, so this thing would have to get pretty darn toasty to destruct. It would be nice if you could invert the PCB and put a large heatsink on it though.

The Sanyo version does have the IC on the bottom, and that's what the heatsink PCB attaches to. You could also install just about any large heatsink on that model.

I'll be working on this off and on over the next week or so and hope to have all the testing and blog published by the end of the next weekend.

[mochti01]

@Martinm210 How do you pick out the tacho signal? My pumps show a signal, but is a bit weird. More voltage -> lower rpm, lower voltage -> higher rpm... Strange, but the pumps work.

[xcooling]

@Martinm210 any chance you can overvolt it to 13v on with the Koolance CTR-SPD10 Pump Speed Controller.


@lowfat its either bad quality control because neither of us can get our pumps to work, or it does not support them.

Ive ordered a DDC1 which i will be trying the mod on... grr will be a few weeks until it arrives.

[SpuTnicK]

@Martinm210 How do you pick out the tacho signal? My pumps show a signal, but is a bit weird. More voltage -> lower rpm, lower voltage -> higher rpm... Strange, but the pumps work.

He is using his multimeter set to frequency (pulse) measurement. Comparing this data with the one from original DDC3.2, he gets a rough multiplier that he uses to calculate the RPM from modded pump.

[RacingTurtle]

Supposedly the plastic can melt at 170C, so this thing would have to get pretty darn toasty to destruct. It would be nice if you could invert the PCB and put a large heatsink on it though.:

Pretty soon we're going to be getting waterblocks for pumps!

[m_jones_]

Pretty soon we're going to be getting waterblocks for pumps!

Waterlogged is one step ahead
http://www.xtremesystems.org/forums/...4&postcount=31

[mochti01]

Here is a little comparison video of a diyinhk 18w ddc 2 and a diyinhk 18w ddc 3.2. Just to check the level of noise.

http://www.youtube.com/watch?v=0OZUg-hETyA

[DumpALump]

So originally I was going to install this mod, but then xcooling said it doesn't work after lowfat couldn't get it to work. Since I have a working MCP355 I figured I'd skip it. Now with this info I think I'm going to have to install it.

[xcooling]

@ DumpALump Please try the mod on your mcp355...

pretty easy to revert it, if it doesn't work.

[Martinm210]

@Martinm210 any chance you can overvolt it to 13v on with the Koolance CTR-SPD10 Pump Speed Controller.


@lowfat its either bad quality control because neither of us can get our pumps to work, or it does not support them.

Ive ordered a DDC1 which i will be trying the mod on... grr will be a few weeks until it arrives.

Yeah, it will go more, but you'll hit a current limit before too long. At almost no restriction I was already almost getting 2.5amps draw at only 12v. I'm curious to get that variable resistor in place and see what happens. At higher restriction, I'm sure you could push 13v if heat is kept in order.

The toshiba is good far beyond 12v, but current and heat may be the constraint. I'ml do some more on this over the weekend.

[DumpALump]

@ DumpALump Please try the mod on your mcp355...

pretty easy to revert it, if it doesn't work.

I'm going to work on it later today. Got everything soldered onto the board yesterday. Actually my first time soldering smd components this small. Not to mention figuring out how to solder the chip. Didn't have any solder paste so I had to do it all with a soldering iron. Actually not too hard.

[mochti01]

I made a video with a 50K variable resistor. Thats really nice to control a Laing with a 6x6mm 50K var. resistor.

http://www.youtube.com/watch?v=qnNWrA4o3Fc

[Martinm210]

Awesome, thanks! That 50K sounds perfect and seems to dial it way down if needed. Voltage control works too, but that resistor would be the better way to go for most people. Then you get a "DDC Strong Vario" of sorts..

[Martinm210]

Alright, I picked up a 50K pot at the shack for a couple of bucks. Now looking at the PCB, it appears there is a trace between Vref and Vsp. I'm assuming I need to remove this trace and connect up the pot something like this?

[DumpALump]

Yeah the way the controller works is through the voltage given to VSP. Since vref outputs 5v that puts it at max. You have to cut the trace since it'd bypass the pot.

You can see the info in http://www.toshiba-components.com/mo...20_080424_.pdf

VSP:
Duty cycle/motor speed control input (This pin has a pull-down resistor.)
0 ≤ VSP ≤ VAD (L): Sets the PWM duty cycle, based on the analog input.
VAD (H) ≤ VSP ≤ VREF: 100% duty cycle (127/128)

0 ≤ VDUTY ≤ VAD (L) → Duty cycle = 0%
VAD (L) ≤ VDUTY ≤ VAD (H) → Figure on the right (1/128 to 127/128)
VAD (H) ≤ VDUTY ≤ VDD → Duty cycle = 100% (127/128)


Since he is using the example application circuit with 100pF Cap and 20kΩ for clock generation

PWM Input Voltage:
VAD (L) = Typical is 1.2v
VAD (H) = Typical is 4.1v

I'm not sure exactly if this would work, but I would figure you could connect Vref to a resistor to ground. Then I would figure you could hook up VSP to a fan controller. It'd have to be an analog voltage though. So possibly control it via a motherboard header. Or you could make a circuit to convert a pwm signal to analog if your motherboard only had fan control via pwm. So then as the heat goes up the pump could speed up. Also could change the parameters of the pwm to analog to set a max voltage applied so it never hit max speed (keep noise down). Just a random thought.

[Martinm210]

Thanks!...It works!

Except I like it this way to make right turn an increase in speed. I tried the 50K pot and a 100K pot. The 100K would go below startup, but the 50K is just right. I used some thinner guage wire about a foot long to the 50K pot and it works out so the resistance is never too much for startup. The current is extremely low, so you could also use one of the mini pots, but they only had 100K at radioshack in the mini sizes.

12V shutoff:
Low end 2,460 RPM (VSP=5V)
High end 6,240 RPM (VSP=2.44V)

Works great..nice DDC Strong Vario..