9 Volt dc motor power supply confusion

hi,

I've been getting closer here thanks to some great help from the board!

I have a new problem though. I've been very satisfied with how the the 9 volt battery I've been using to test my motor ( http://www.allelectronics.com/make-a-store/item/DCM-367/6-20-VDC-MOTOR/1.html) has been running, I'm ready to transfer it over to a wall wart (first time using a wall wart with a project).

I bought two power supplies a 800 ma 9v and a 300. When I hook the motor up to the 800 ma wall wart the motor spins much faster and over heats really quick.

Oddly ( to me anyways) when I hook it up to the 300 ma the motor pulses on and off pretty rapidly Pretty much every second in rhythm. I'm wondering if there is an explanation for this.

Here are my other questions. Should I be looking to get a lower mA wall wart to decrease the speed? perhaps 500? Or is the speed on this motor controlled by the voltage? What would be a power supply that would be a proper replacement for a regular 9 volt battery?

Any explanation for the pulsing?

Thanks again for the help!

http://ww4.aitsafe.com/cf/inv.pht?id=2417000&lg=0&us=6068979&sd=

No-load rating @ 18Vdc: 0.25A,

So, why are you using a 9V power supply?

What is the measured output voltage of your wallwart, and the output needs to be DC (not AC). The motor should be ok at 9v per the ad specs.

sorry---? doesn't the 6-20 dvc mean thats its range?

Sorry maybe a bit of a fool over here---

I've also been using this motor

http://www.radioshack.com/product/index.jsp?productId=2102827

which I believe does have that range---

So, why are you using a 9V power supply?

The motor specs seem to be 6v-20v, so why not? The poster seemed to be happy with the 9v performance.

the voltage is reading at 10.2 volt when running through to the motor

Would the mA effect the speed and heat increase?

The mA rating of a power supply is how much current can be supplied.

Do you have links for the power supplies you are using?