11mm wide case design offers a thin servo for easy installation
JR 3 year warranty
Metal geartrain provides durability and longevity
Proven JR precision for accuracy and performance
High Speed for better performance
The DS378HV offers the superb holding torque, minimal dead band and high resolution of JR digital technology in a package that's ideal for high-performance aircraft. Its impressive 75 oz-in of available torque is sure to withstand higher demanding applications. Features such as the 11mm wide case design, metal geartrain, and ability to use 2S Li-Po batteries without a regulator with simpler set up for better performance makes this servo top notch. Combine these features with a JR’s 3 year warranty makes this servo a great value for all enthusiast.
Battery chemistries such as LiPo, LiIon, and LiFe have become very popular within the RC community. They are the standard for powering electric motors and have also gained popularity as receiver battery packs. The issue is the output voltage of these batteries is higher then the previous standard 4 - and 5-cell NiCd and NiMH packs, 4.8V and 6V respectively. The higher voltage is not an issue with the receivers but can be for the servos. Many servos will not operate at these higher voltages for very long before burning out the motors or electronics.
To get around this issue modelers have had to use a regulator to drop the voltage to an acceptable operating range for their servos, usually around 5 to 6 volts. The addition of a regulator adds a component that, should it fail, can cause the loss of a model.
JR’s HV servos are designed with motors and electronics that operate off the direct voltage of a 2-cell LiPo, LiIon, or LiFe receiver battery pack (6.6V to 7.4V nominal voltage). This eliminates the need for a regulator and lowers the chance for a power failure that can cause a catastrophic failure of your model. Also note that the HV servo specs are shown at the higher voltage (7.4V 2S LiPo) but will still operate on a standard 5-cell 6V NiCd, Ni MH battery with a reduction in performance of approximately 10% in speed and torque.
Digital and analog servos have very similar construction and components. They both use the same type of motors, gears, cases, and have a potentiometer. A digital servo is different in the way it processes the incoming signal and converts that signal into servo movement.
An analog servo when it receives a command to move, takes that signal and sends pulses to the servo motor at about 50 cycles per second, which in turn moves the motor to its required position determined by the potentiometer.
A digital servo has a micro-processor that receives the signal and then adjusts the pulse length and amount of power to the servo motor to achieve optimum servo performance and precision. A digital servo sends these pulses to the motor at a much higher frequency which is around 300 cycles per second. This helps eliminate deadband, provides a faster response to the servo motor, smoother motor movement, and has higher resolution and holding power than an analog servo.
There are some disadvantages to digital servos, but the disadvantages are not in any way close to out weighing the advantages. A digital servo will have a higher power consumption (Around 10 to 15 mAh per servo at idle) than an analog servo due to its higher pulse frequency, so larger capacity battery packs are recommended. Digital servos also are more expensive than analog servos which can get very costly in applications that require many servos.