Actually, blocking the nozzle allows a motor to spin more freely because of reduced air resistance. That's why a vacuum speeds up when blocked. The motor may overheat from lack of air flow, but the power supply is actually getting a rest.

Bottom line, your power supply is barely making it. A vacuum needs power to do its job, that's simple thermodynamics; force times distance shaft work. No horsing around is going to change that. You might degrade the performance of the motor in some way to better allow the power supply to keep up, but a better power supply is so much simpler.

 

wayneh,

I see your point. I guess I will either have to get a better power supply or just rework this project. Thanks.

 

I think I have found a few more AC adapters at work and at home that I might be able to use instead of the one in the diagram I posted. I have:

16V 7.5A AC adapter
15V 8A AC adapter

Do you think either of these would be just enough to supply sufficient power to my project? If so, would one be better than the other? Thanks.

 

they are both 120W try them out and see

 

Hello,

Are the outputs of the adapters AC or DC?
You can not feed AC to a DC motor.

Bertus

 

Sorry, I was not clear. The output of both power sources is DC. They are power supplies for laptop computers (wall worts?).

 

Also, if the data sheet for the DC motor says the stall current is 46.6A, maximum efficiency current is 9.16A, and no load current is 1.8A, does this mean that I need to use a power supply that can supply at least 46.6A? Or is it usually OK to use a power supply that supplies less amps?

 

If you use a supply with less current available, use a start capacitor to get the motor going.

Google "Motor Start Capacitor" for more info.

 

Sorry, I was not clear. The output of both power sources is DC. They are power supplies for laptop computers (wall worts?).

Why have you not tried them yet?

Also, if the data sheet for the DC motor says the stall current is 46.6A, maximum efficiency current is 9.16A, and no load current is 1.8A, does this mean that I need to use a power supply that can supply at least 46.6A? Or is it usually OK to use a power supply that supplies less amps?

From what I gather, the cost of a 46A power supply is not in your budget. whatever capacitors are in the power supply probably provide that initial starting current. if you find that the capacitors aren't up to the task, try adding a real big capacitor or a rechargable battery in parallel with the wall wart to pickup the slack when there is a high current demand, like how the battery is setup in a car-continuous charging/discharging. make sure that your wall wart doesn't put out more amps than the recommended charging current of the battery. If you aren't comfy with that idea, try using a switch so that you can start the motor and run it say.5sec on battery, then switch over to wall wart. Still don't like that, try adding a resistor in series with the motor which can be switched out of series to prevent overcurrent at startup.