Run pump off 12v line?

[Conumdrum]

You drop half the AC wave, your at 25 hz. No AC pump will run right at less than half it's rated Hz. Man, just get a new pump.

 

[Sam__]

@ sunrunner20 - thanks, and I'm running an Eheim 1250
@ Conumdrum - Would the pump just run slower with less Hz?

Thanks for all the advice. I'll see if I can try the diode idea. Im kinda turning this into a bit of a project so i dont rele wanna get a new pump cos its kinda fun learning all bout this stuff.

 

[th3]

It will not give 25Hz out, 1 cycle is 360 degrees, by cutting off 180 degrees with a diode you are still at the same frequency, you are removing a part of a each sine wave, not every second sine wave. However if using a full wave rectifier you are doubling the frequency from 50 to 100 Hz.

 

[sunrunner20]

From my understanding of how the 1250 works (I have one) It simply won't run without the "bottom" half of the wave.

 

[Sam__]

From my understanding of how the 1250 works (I have one) It simply won't run without the "bottom" half of the wave.

thats a bit of a bummer. How come it doesnt work?

 

[sunrunner20]

thats a bit of a bummer. How come it doesnt work?

The 1250 uses a magnetic coupling. Meaning: The impeller has no direct linkage. Instead, there is a permanent magnet on the impeller and there is circuitry inside the 1250 that rotates a magnetic field around the permanent magnet on the impeller, thus spinning the impeller and pumping the water.

Unfortunately, the processes uses both sides of the sine wave, so with only half a wave you'd be lucky for it to even spin.


I should probably dissect my 1250... (it died and needs a new impeller... not worth the $$)