None of the pumps have variable output, and wifey would like to be able to control the waterfall’s aggressiveness in her Terrarium.
I’m not sure if they are single phase, asynchronous induction, etc. And the pumps are so cheap they don’t say.
Thoughts?
Thanks
Weston
What is the wattage of the rheostat vs the wattage of the pump?
10 Watt pump, 150 Watt rheostat
Should…that’s a pretty big rheostat power wise
Ahhh this stuff just has 2 blade standard US plugs on it, so I don’t know that I’ll be wiring stuff, unless necessary.
Here’s an example of the rheostat:
http://www.amazon.com/gp/aw/d/B001OVD7Q8?cache=50af4f69ab42d96e4ebc8a89ee6c4a51&pi=SY200_QL40&qid=1406176730&sr=8-1#ref=mp_s_a_1_1
And a pump:
ah ok…found something like this
Big listing
While what has been proposed here will definitely work, you are going to have the resistance of the Rheostat connected across the power supply at all times, so it will always be dissipating considerable power (heat), no matter what the load on the voltage divider is. I’d drop the connection at C, and simply use the Rheostat as a variable resitor in series with the motor. If it is a shunt wound motor, I’d wire the Rheostat in series with the Shunt winding. It is counter intuitive, but the less voltage applied on the shunt winding, the faster the motor will turn. The shunt winding generally consumes very little power relative to the rotor winding, so the energey wasted as heat in the Rheostat will be much smaller than if you placed both windings in series with the Rheostat.
Got a schematic for that wiring please?
This has gotten good reviews from some of the slot car guys using them to turn down voltage on power supplies.
Whether it work for your pump?
90 day no question return policy means there is no risk to you to try it.
http://www.harborfreight.com/router-speed-control-43060.html
HTH
Keith
For universal DC/AC motor, not induction motor (caution!), try 1.5 amp diode (Radio Shack) on one side of AC cord. You have cut & butt splice or solder but $1 or so. Flow may be right as long as pump does not object.
You could also make Y or T output diverter to reduce flow in one direction. Trimming the plastic impeller blades may be an option since we are talking cheap and are replaceable. If none of the above agreeable, buy the next model up with adjustable flow control which may be cheaper than $20 speed controller which may still cause problems with the reduced voltage and normally designed for universal motors such as drill and Dremel type motors.
Hey guys I really appreciate your suggestions!
I’ll let you know how it goes!