I had a question concerning powering a 8.4v servo. Here is the one I am using:
Servo
It says it takes 6-8.4v and 2.4-3a, and I wanted to use a power supply that outputs 9v and 2a dc. If I use a buck converter to convert this to 8v, the amps would increase, correct?
If I use P=VI, then the current would only be 2.25 (?). Would it increase enough to destroy the servo?
I've heard suggestions to use a Lipo battery, but I wanted this to plug into a wall socket for power.
(I am new to electronics)
Even if the current CAPABILITY increases it does not mean that the increased capacity wil get used. The circuit will pull only what it needs.
Instead of a buck converter I would put 2 or 3 silicon rectifer diodes in series with the 9V. Each diode will drop about 0.6V which is OK for the servo and the Ardino Vin (depends on 5V rail loading). Also provides reverse polarity protection.
I would look at a bigger power source, the one picked will be overloaded when servo starts, possibly causing a voltage sag. Hint: If a device uses a given amount of current, that will not change as long as the voltage remains the same regardless of the voltage source. Play with the ohm's on line calculator: Ohms Law Calculator This will help you see the relationship to voltage, current, power, resistance.