Hydor Koralia Nano 12V

[k20fa5]

I bought a set of slightly used 12V Koralia's. My intention was to never spend the $300 for the Hydor controller, but to make my own....

 

Well, that is where my problem starts. I can't get either of them to fire from a 12V power supply? They start to turn for about 1 second, then stop??????

 

Does anyone have any ideas on how these things are supposed to run? Start up? What does the Hydor controller do?

 

I may end up selling these and getting a couple of regular Koralia Nanos?

 

Any help is appreciated.

 

Brian

[braddo]

I was considering purchasing a few and building my own controller as well however I found a few posts elsewhere stating that the controllable koralia pumps are AC not DC.

[k20fa5]

I was considering purchasing a few and building my own controller as well however I found a few posts elsewhere stating that the controllable koralia pumps are AC not DC.

 

I'll have to look at them tomorrow. I could have sworn it said 12VDC on them. If not, a 12VAC transformer at Fry's is pretty cheap. I'll look and see.

 

Brian

[evilc66]

They are 12v DC. What may be happening is a failure mode for the Koralia. Short circuit protection if you will. The controller has a PWM (pulse width modulation) output to run the pumps, and may only have a 90-95% duty cycle for full flow. A 100% duty cycle (internal short in the controller) may trigger a saftey mechanism that stops the pump from causing more potential damage.

 

I'm sure it can be done. You can build a simple PWM motor driver from a 555 timer circuit connected to a FET to run the pump. Would only cost about $10-$15 in parts to do it, and most can be found at Radioshack.

[jl7854]

They are 12v DC. What may be happening is a failure mode for the Koralia. Short circuit protection if you will. The controller has a PWM (pulse width modulation) output to run the pumps...

 

I have been reading about these Koralia pumps and it seems that this AC DC question is all over the place. One guy saying he could only get his to work with DC, but he may have been in Europe. Others have said that they got some movement with AC. It seems that few with electrical experience have actually tackled the problem and no one has shown a working solution. The threads always end with it must be one or the other. You seem to be the electrical guy here, have you actually gotten one of these pumps to run with 12v DC?

 

Jon

[evilc66]

Haven't tackled one head on yet, but I have been reading about them. I might buy a nano to play with it.

 

DC operation makes much more sense for a controllable pump. It's much easier to control the speed of a DC pump via pwm than frequency modulation on an AC motor and have it run smoothly.