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Arduino – Servo Motors Testing
These are high torque motors (33 kg-cm) and has a very high stall current rating (3A) It needs a an external power source. In our case it is powered by a LiFe battery as it gives a 6.6 volts which is appropriate voltage for the servos.
We also made an adapter board where all the wires are hooked up for positive and ground connections. The data pins of all the servos are connected to the Arduino.
, https://i.ytimg.com/vi/KjaYItG93YQ/hqdefault.jpg
source
how to make the circuit of two servo motors running in opposite direction using external power supply
Schematics please
Man how can you move them slowly???