While we have many excellent options in buying new DDC pumps, who doesn’t like the idea of modifying one or repairing an old broken pump especially if it means more performance and/or variable speed capabilites. Thanks to a DIYINHK, we have some options to play with. Wizard1238 posted the information about his DIY kits on xtremesystems here and it quickly caught my interest.
A special thanks to wizzard1238 at DIYINHK, check out his Ebay store for DDC mods and projects.
He sent me over one of each of his PCB mods along with one pump with the mod already installed. This first test is looking at is Toshiba controller which was already installed on a blue impeller DDC pump. I believe this could be installed on a variety of DDC motors including the DDC1 and DDC2, but there is some question about DDC3 compatibility. The motor he sent was an old DDC3 motor from a Mac G5, and there is some extension of wires required to make that mod work as you’ll see in the photo below.
Blue Rotor DDC (Toshiba PCB preinstalled)
First a few pictures of the modded pump with the new PCB that was sent, as noted…I haven’t tried this myself but I will in time at least on some DDC1 motors that I have handy.
The new PCB that was soldered in place and the new motor controller (Toshiba TB6588FG) makes this a whole different pump electrically. I did a little searching and found some good information on this controller here:
These are some of the features of this controller:
- Sensorless drive in three-phase full-wave mode
- PWM chopper control
- Controls the PWM duty cycle, based on an analog input (7-bit ADC)
- Output current: IOUT = 1.5 A typ. (2.5 A max)
- Power supply: VM = 7 to 42 V (50 V max)
- Overcurrent protection
- Forward and reverse rotation
- Lead angle control (0°, 7.5°, 15°, 30°)
- Overlapping commutation
- Rotation speed detecting signal
- DC excitation mode to improve starting characteristics
- Adjustable DC excitation time and forced commutation time for a startup operation
- Forced commutation frequency control: fosc/(6 × 216), fosc/(6 × 217), fosc/(6 × 218), fosc/(6 × 219
The other detail I found in the technical document is that Tjmax = 150C, it also has built in thermal protection which is pretty cool.
Here is a closer look at the PCB as a whole. It comes packaged in a very nice hard plastic reusable case.
I haven’t done that yet, but the idea is to desolder the original laing PCB and replace it with the above. The PCB is also likely glued down at the FETs with epoxy, so it may take some force to get the old PCB removed. Careful attention to winding wire direction and power feed are critical. Also the winding wires must not touch the magnets, etc. I would also advise to take care when soldering thicker guage wires that you don’t accidentally pry on the contact with the wire. I managed to break the Tach contact on mine and had to very carefully resolder to the tiny trace nearby. While the PCB thickness is very durable, the contact traces are fragile and you should be very delicate with them where you solder wires, and pre-bend the wires before soldering so you don’t accidentally pry the trace pad off the PCB like I did. A fine lower wattage iron with flux handy would also be a good idea.
When I do my own, I’ll update this portion with some notes about the installation experience , for now I’ve decided to move forward with testing the pre modded pumps that were sent on the next page…
Update: I have done this now on a DDC-1 pump, you can see a video of the Sanyo install on my Sanyo blog here:
It is a fairly advanced soldering project for it’s micro size, but not so hard that I couldn’t manage. The hardest part is extending coil wires which isn’t necessary in the DDC-1 install unless you break a coil wire. The DDC3 pumps however have a completely different winding setup, so you will have to extend the wires and protect those extended wires with heatshrink tubing to prevent contact with the coil or with the magnets, etc. I would also HIGHLY recommend that you find some very fine tweezers before attempting this, you need something small enough to grab and pull on the coil wires while desoldering.
And for those that are brave enough solder the SMT components to the board, I’ll provide this detail blow up of the soldering area so you can see the diode direction, etc. I did not attempt the separate components alternative myself so I can’t comment on how difficult that is.