Model: DS04-NFC 
For HM / Cars / Robotics 
Weight: 38g 
Dimensions: 40.8 x 20 x 39.5 mm 
Torque: 5.5kg / cm (at 4.8V) 
Speed: 0.22sec / 60 ° (at 4.8V) 
Operating voltage: 4.8v-6v 
Operating temperature: 0 ℃ -60 ℃ 
Current: <1000mA 
  
  
As long as the input signal terminal a 50HZ square wave signal, and then controls the duration of the high-level pulse signal cycle can control the speed and reversing and stalling. A high level pulse duration corresponds to a speed. HIGH 1 ms - 1.5 ms Forward steering gear (1 millisecond when the forward speed of the fastest, the slower the closer to 1.5 ms, 1.5 ms servo stall), a high level of 1.5 ms to 2 ms when the servo reverse (1.5 ms servo stalling, the closer reverse speed 2 ms faster 2 ms to the fastest speed reverse). 
The servo band position adjustment potentiometer (open shell pry the circuit board to see), debugging can be provided at a high level pulse 1.5 ms, observe whether the servo is stopped, if you turn on the stop adjustment potentiometer is, until the stop date, thus completing the zero.