Backyard Aquaponics
A place to discuss aquaponics

I was wondering if anyone had experimented with putting a light dimmer switch (pentometer?) inline for their pump power supply? I don't like the idea of using valves to control my water flow as it adds extra "head" pressure to the pump and will eventually cause premature failure. By regulating the power supply you should be able to control your pump speed and flow to what is required by your system. You would also reduce your power usage if this works. If anyone has tried this I'd be interested to know what your findings were! It will save me the $10-$20 on parts to experiment. Any comments greatly appreciated.

Theres no real need to throttle your water pump. Just direct excess flow back to the FT for free aeration

Another note is if you do throttle a pump back it uses less energy. Hard to believe? Yes, I did too.

yeah, I wouldn't throttle the pump, i'd just add a loop back to the pond.

if you want less flow, buy a smaller pump.

Dont you mean it will use more energy as it has to work harder due to the restriction of flow?

Yea I thought so too Arbe.

Heres the discussion from a while back where Werdna brutally put me back in my hole

viewtopic.php?f=5&t=13312&hilit=hydraulic&start=60

I still dont fully understand it..

I think a dimmer switch probably just dumps excess power as heat. Or at least that's the totally inefficient way I would make a dimmer switch.

And +1 for just diverting water back to your fishtank with a tap mounted just above the water line so you get some extra aeration.

Dimmers use an SCR -- basically a diode that 'turns on' when the voltage gets to a certain level. And then turn off when the voltage reverses. So you still get a 50 Hz wave, but it's very spikey.

Fine for a light bulb, perhaps not so fine for a motor...

You might be better off with a sewing machine pedal.

Actually BW, modern dimmers use a triac in a chopper circuit.

Pots stopped being used around the 80s from memory. They are a fire hazard, bulky and inefficient.


Beaten by Nebbian

Ok thanks for the input folkz, a extra return line it is

This
http://www.siliconchip.com.au/Issue/200 ... Controller
or
http://www.siliconchip.com.au/Issue/200 ... er%2C+Mk.2

But I still don't know what sort of motor these submersible pumps are !!!

permanent magnet ? OR some other type (universal?) with mag drive...

Once this is known then more options RE speed control etc will be available to us.

they might be synchronous motors...

BUT there is this !
http://www.siliconchip.com.au/Issue/201 ... er%2C+Pt.1

HOWEVER if your pump is the brushless type (with electronics) then no go... Joe.
I think mine (Jabao eco-tech whatever) could be brushless.
Can't do much about them but they are pretty efficient anyway...

http://en.wikipedia.org/wiki/Variable-frequency_drive
That's the good stuff, just take care you have got a three phase motor on your pump, even if it is plugged on one phase , there's a capacitor on it.