Q about power sources

hi, i am very new to arduino and have little to no experience with this type of hardware

and was wonderin if i was to connect some motors to my arduino can I construct or buy somethin that would allow me to run power to the motors without running it through the arduino?

(the electric moters i was planning to use come from a toy bulldozer and use 4 or maybe 6 D -ize batteries and i dont think i should pull that amount of current or power through the arduino circut)

any help would be appreciated

Relays and Transistors will isolate your Arduino from your motors.

thanks, now to google those things

http://arduino-info.wikispaces.com/RelayIsolation
http://arduino-info.wikispaces.com/DC-Motors

You might also find this useful: it explains the transistor in words that made sense even to moi.

Most DC motor controller boards and shields (like the popular ones based on the L293 and L298) for the Arduino allow you to power the motors via an external power source. Some require the Arduino board to supply the logic supply for the h-bridge; others have an on-board regulator, and can take the power from the motor supply. Some have jumpers to select what you want; some can even power the Arduino (ie, the supply for the motor and driver board also powers the Arduino).

Above all else, you need to know the voltage of your motors, and the worst-case (stall) current needs of them - before you can select -any- controller. If you don't have a multimeter to measure this, that meter should be your -first- purchase.