Hydor Koralia Nano 12V controllable pumps are 12V AC. Gutted!

So, I'm building my own multi-tank aquarium controller. http://forum.simplydiscus.com/showth...xpI-O-over-i2c

One element of the design of the tanks has the water enterning one end of the 30" long 20gallon long aquarium and exiting at the opposite end of the aquarium. (this is because all plumbing is hidden along the ends, and the tanks have a clear view from the front and back sides). I was concerned about dead spots, and the likelihood that I wouldn't collect as much detritus during water changes.

I have 5 Hydor Koralia Nano 12V pumps (new old stock that I aquired super cheap a couple of years ago). My intention was to run them at a low speed to just to encourage a bit more circulation throughout the water column, and then to kick them up to full speed a few minutes before and during the automated water change cycle where about 30% of the water will be changed out once or twice a week.

This week, I started to select an i2c PWM board capable of 12v/8w operation per channel. Just prior to purchase, I thought I'd better test out the theory (as the board is spendy) with the pieces/parts I had to enable PWM to control 0-12v. And that's when I learned these pumps are not 12V DC... Nope.. all I got was a single click and no movement... I had no idea. Started searching.. and learned that a few pioneering folks learned this a decade ago... https://www.nano-reef.com/forums/top...ge/2/#comments and http://www.reefcentral.com/forums/sh....php?t=1731232. In fact the control of them is quite complex as it's a squared off sinusoidal wave.... and that level of DIY electrical engineering is beyond my pay grade.

Just a killer. So now, I'm going to see if I can at least run them off of a 16V a/c doorbell transformer. Folks commented that plain 12v ac didn't rotate them very much, but that 16v ac actually seemed to be the ticket. Anyway, I have 5, so I can destroy 1 messing around. If it works, it will be a simple implementation of just switching, via relay board that i already have, all 4 of them together to either improve circulation or water change effectiveness, but probably not both.

It's a bummer when you buy the wrong stuff. Sorry, just felt like airing a little frustration.

Way beyond my understanding. I'm lucky to send a text message, but good luck.
NCH

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Originally Posted by NCHornet

Way beyond my understanding. I'm lucky to send a text message, but good luck.
NCH

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I'm not sure that I understand it all either. I'm just a nerd who can't leave well enough alone sometimes.