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Unread 12-03-2004, 12:06 AM   #1
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Join Date: Nov 2003
Location: U.S.A.
Posts: 68
Default AquaXtreme or MCP-600 R.P.M. Signal Mod.

AquaXtreme or MCP-600 R.P.M. Signal Mod.

Hello people, this is my first mod-guide, hopefully I can make this easy for everybody to understand (English is my second language). First I have to thanks Spiv at (dead link)for an excellent article on how to get R.P.M. signal from fans without R.P.M cable, after reading this article I study the possibility to use his same principle on water pumps, and the key word was “Hall Sensor”

The Basics:

Basically all brushless motors use hall sensors. The Hall sensors signal magnet position and polarity information to a logic circuit. This mod will convert the out-put signal of 1 of the hall sensors inside the AcuaXtreme pump (or MCP-600, same pump) into R.P.M. signal to the motherboard.

The parts I used:
ULN2803 Darlington array chip (Jameco #34315)

18 pin IC socket (Jameco #112230)

General Purpose Prototyping Board

Vertical Terminal Blocks

The Circuit:

I am using this mod on my next computer project (soon to hit a forum near you). I will be using 2 AcuaXtreme pumps. First I took the impeller housing (by doing this you can run the motor without water) and carefully removed the plastic clip that hold the power cables in place at the base of the pump.

Next step, I took apart the back plate, bolted to it you find a circuit board with 3 hall sensors.

This mod will require the out-put signal coming from 1 of the hall sensors. I used the out-put from the middle sensor (yellow cable).

Now just splice, solder a long cable to it and insulate with heat shrink tube and re-wire the cable to the front. Note I did not solder directly to the hall sensor, this may burn the sensor. I put together the pumps without the impeller housing for testing.

Next step, I connected everything together.

Both pumps read an average of 4200 R.P.M. with power, and 0 R.P.M. without power, when resistance is applied to the impeller base R.P.M will decrease.

Hopefully this mod can be usefull for some one out there, pleace feel free to
give any advice on how to make this mod better.
This mod will void any warranty on your pump. If you want to do it, do it on your own risk.

Last edited by Maximilium; 04-15-2005 at 06:15 PM.
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