DC pump control

_shorty_

New member
I just picked up an Aqua Medic DC Runner Controllable Pump - 3.0 for some additional internal flow in a new tank I'm setting up. I wanted at least one internal pump to be DC so I could randomize flow a bit. The controller has power up, power down, and feed buttons. It ramps up slowly when turned on.

I'm assuming I could hack the controller (or build one) to control at will via PWM with my arduino controller that I've built.

However, it'd be really easy to put the power supply on a relay. Would it be harmful to cut power to the 24V power supply every few minutes, and then reapply power to provide ramping/alternating flow? Would this be much different than hitting the 'feed' button?.. Any concern with this idea?
 
_shorty_, I am not familiar with that pump, but if it follows the typical DC pump control mechanism, 1 pin on the cable should be Ground, 1 pin +24V and the last pin should be a 5V analog signal to control the speed. If you have a multimeter that can be used to examine the connector coming out of the controller looking for the 24V and Ground, that will go along ways to confirming the needed control scheme.

The other possible control scheme is 3 phase BLDC. That type is alot harder to DIY, it is what the Gyre uses. I have a project in the works for a DIY controller for that, that I will hopefully get back to soon.

For the Jebao DC pumps, I simply reduce the 5V control line to 0V and the pump stops. I don't bother cutting the power to the transformer. I have been doing this for more than a year and have not had any issues yet.

Dennis
 
awesome! Thanks so much for the feedback. That would be super easy to control then if it's the first type and bypass the controller completely. Then I wouldn't have to worry about a relay burning out on me. I'll put a multi-meter on it once I get it in and figure it out.
 
Dennis, Upon further thought, do you have any idea how many amps your 5V control line draws on the jaebo pumps? Are you outputting directly from an arduino (or similar) output pin? Any need for diode or any other protective circuitry?
 
Yup, the Jebao pumps use a 0-5V analog. You can do a low pass filter as jimbob321 suggested or you can add a DAC breakout board. I use the Adafruit I2C MCP4725 (http://www.adafruit.com/product/935) to control my WP40s. They only have 1 address pin, so you are limited to 2 of the DACs per I2C bus unless you get creative.

I use a Raspberry Pi to interface to it, but Adafruit has Arduino libraries and example code as well.

Oh, unless you want 100% and 0% only (On/Off), in which case you could drive the 5V line directly from an Arduino. The draw should be minimal so the Arduino would have plenty of current.

Dennis
 
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