... sorry for the SSR comment. Koralias that I have are 115V AC. I forgot for a sec that you guys are in 12V controllable land.

Given the complexity of PMW on a different potential than the standard Arduino output, It might be easier to test first using a PMW capable SSR on 115V. ... just a thought.
Marian

I thought about that,
but I'm not the guy to do a schematic for it.
Heck if it works it would be cheaper than the controllable ones

Most AC motors don't do well running on pwm to slow the speed. Adjusting the frequency is a better option for those types of motors. The frequency you would need to switch at would make the SSR impractical.

After many hours of searching finally found some articels about the electronics of the controllers.
http://www.microchip.com/stellent/idcplg?I...ppnote=en012135
http://www.microchip.com/stellent/idcplg?I...ppnote=en022135
Now only I have to understand them

Yup those articles are useful. In fact, I used the code to generate my pwm gating signals on dsPIC33. It's the hardware I'm having problems with. So~ if anybody out there has extremely good knowledge on smps, inverter or anything that makes use of power mosfets, please send me a PM. I don't know much about selecting the right mosfet and driver for this application ^^. Thanks!

Would something like this be useful for this application?
http://www.freescale.com/files/microcontro...r/MC3PHACWP.pdf

Possible. We will need to investigate it further. We are still investigating the output of the controller too so that we can better pick a product like that.

It does the same as the PIC controllers mentioned above. The koralia isn't a 3 phase AC motor, but we need a solution to one phase AC motors.

An interesting video.
http://www.youtube.com/watch?v=qFmqPBjZevc

Hey evil, I know you must be excitingly busy ^^. Did you get a chance to do more waveform analysis? I'm still quite interested heh.

Not yet. I'll see if I can get to it this week.

Here is an interesting patent for a Variable frequency drive for AC synchronous motors with application to pumps.


http://www.freepatentsonline.com/7202619.html

My nano is a 200g DIY plywood tank, but I am very interested in this NAMIZOU DIY wavemaker for korallia pumps. Does any one have any info on them?

I do have a plywood/ epoxy tank with a glass viewing pane in front. Korallias won't hold through nearly 1" thick plywood and epoxy/ epoxy paint, so suregrip large magnets will work, Would this, the DIY 20 dollar DIY wavemaker work on the MJ modded prop pumps?

Tom

The wavemaker you are talking about is a little different than what we are talking about. The Namizou wavemaker is a wavebox, similar to the Tunze unit. It's also called a tidal surge unit. You could use any pump that could create enough pressure to empty the wave box.

Not sure if this helps. I cant understand it...

http://www.rcgroups.com/forums/showthread.php?p=594518

That's for single phase DC brushless motors. It was a cool read, but the drive signal is a little different being AC.

wow, that schematic is very useful. I've been having a difficult time trying to select the proper mosfets to make an h-bridge for motor applications like this. Thanks alot!

A DC brushless motor is kinda like a synchronous AC motor. I think aquarium powerheads are like hybrid sensorless synchronous motor.

Glad it helps, I just want to see either the DIY vortech thread or this thread get something working.

If I can program either of them into something like the 89$ reef controller I will be thrilled.

I really think that we have the skills to complete either project. That would open up so many possibilities for us and is exactly what I want for this project.

http://www.nano-reef.com/forums/index.php?...=191565&hl=

The namizou does not look like a wave box to me. I watched the video again, and all I can see on one side is a hang on aquaclear or similar filter, but no wavebox similar to anything like the tunze.

Maybe I am missing something?

I was thinking of taking a $5 car inverter from harbor freight and replacing the 60hz ocsillator controller to make a 1phase vfd for a fan. But, like most, no time.

evilc66, do you think it would be possible for you to connect your Koralia controller to the oscilloscope again by time base set to 10ms/div instead of 50us/div? Your graphs show the sampling freq is set to 20kHz but we can not see what the output sine frequency is at min and max pump output. I have my Koralia nano running on 12 V @ 50 Hz (EU), but am not really pleased with it's output. My guess is the frequency is varied somewhere between 20 and 100 Hz, but don't know the exact numbers. Your pictures would solve the mystery THX in advance for doing it and i understand if you don't do it also...

I will see what I can do this week.

Hey evilc66 great work you have done there. I recon a week might be a tad longer over at your place, but I would highly appreciated if you could post some more scope pictures.

To build my H-Bridge I'm using a pair of Mostfet Drivers + Mosfets clocked by an attiny2313.

At first I've tried driving the motor with a SPWM signal, using a PWM signal of 25khz and a AC frequency of 50-60. This worked ok-ish but startup give audible clicks and any modulation resulted in errant pump behaviour.

Next try was to again use the same 25khz PWM but instead of a SPWM output I would just use the same PWM value for all ticks of a given half - wave. With the right combination of frequency and PWM this gives a nice and mostly quiet start up, but modulating the PWM utilization doesnt give a lot of different pump power values.

From your scope pictures it seems that even when PWM'ing one half of the 60HZ AC wave it uses both Mosfet Pairs?

Is that the correct way to do it? My code goes like this:

Enable N-Mosfet 1 | Disable N-Mosfet 2
PWM P-Mosfet 2 for a half wave of the 60HZ Singal.

Disable N-Mosfet 1 | Enable N-Mosfet 2
PWM P-Mosfet 1 for a half wave of the 60HZ Singal.

Yeah I know, I should atleast be PWMing the N-Channel in this case but I mixed up

Sorry for digging this year old thread up. But im kinda stuck without a real controller and when googling if others worked with the Koralia I came across this thread.

ps.: The Pump seems to work at both 50hz and 60hz but my impression is that 60hz is a tad better. Still I'd guess theres no 60hz / 50hz for USA and Europe respectively since the pump frequency is not related to the mains frequency.

thanks in advance
ash-ash

Addendum:

I misinterpreted the scope plots. It doesn't go into the negative part for the high frequency carrier wave.