lightweight, inexpensive speed controllers

[efoote868]

Originally Posted by yash101

Also, using a linear voltage regulator at those currents would cause the magic smoke of death to puff out of the regulator. Powering my RasPi from an LDO gets the chip so hot, I have it connected to the aluminum chassey of the robot for a ginormous heat sink!

Depending on the current draw of the controller, as well as the supply voltage of the battery, a low dropout regulator may be just fine. Basically what you need to remember is the difference in the battery voltage and supply voltage is just waste at the linear regulator.

If you have a 12V battery with a 5V linear regulator, drawing 700mA from it will cause it to act as a 4.9W space heater (gets hot very quickly).
If you have a 7.4V battery with a 5V linear regulator, drawing 50mA will only waste .12W, which is much more manageable from a power dissipation perspective.

[yash101]

Yeah. Thee Arduino should draw about .2-.5A. The Gyro and other sensors may use up more, so you may use close to 1A/Hr!

[ILAMtitan]

Originally Posted by yash101

Yeah. Thee Arduino should draw about .2-.5A. The Gyro and other sensors may use up more, so you may use close to 1A/Hr!

An Arduino running at full tilt will only consume about 20mA, and only 12mA of that is the Atemga itself. Gyros will pull maybe 4mA (x3 though). Toss on an LCD like the KK2 model uses (which I HIGHLY recommend), and your power budget for the control board is still in the sub 50mA range.

On a quad, or any aircraft, the bulk of the power is consumed in the motors, and the rest is such a small percentage you can basically ignore it. With a 20A ESC, that control system is taking less than one percent of the total power. A small UBEC will work just fine.