Non-Switching Driver

Optimal driver for applications measuring small signals that detect ON/OFF noise

The non-switching driver controls the rotation of an air spindle, which is a rotating mechanism typically found in disk test equipments. Because the equipments used to manufacture and test hard disks used in many personal computers and home appliances handle small signals, it is important to reduce the electromagnetic noise of non-switching drivers, while maintaining high-precision rotation speed.
We offer a non-switching driver that suppresses the noise caused by the non-switching (linear) operation of the power device that drives the motor, while achieving high-precision, high-speed rotation through PLL control*2by encoder signals*1.

  • Encoder signal:Rectangular clock signal corresponding to rotation speed output from the encoder installed on the spindle to detect rotaion speed
  • PLL(phase-locked loop)control: A method to maintain high speed-precision by synchronizing the rotation reference clock from a higher level device with the encoder pulse from the encoder built into the air spindle


Suitable for applications measuring small signals that detest ON/OFF noise



  • Stable rotation within a wide speed range
  • Highly responsive current control
  • Noiseless non-switching operation
  • PLL and torque (current) control
  • EU RoHS compliance


NS20-A Dimensions

Location of threaded holes for fixing brackets

NS20-A from A

Dimensions and view from A
(In case of using threaded holes at top side)

NS20-A from B

Dimensions and view from B
(In case of using threaded holes at bottom plate)

NS20-A from C

Dimensions and view from C
(In case of using threaded holes at back side)

Length of M3 threaded bolts must be fixing plate thickness plus 5 - 6mm.
If the bolt length is too long that may cause internal contact.


Type NS20-A
Applied Motor Three-phase synchronous motor*1
Applied Encoder Incremental encoder (Max.5MHz)*1
Power Main Power ±24V (8.5A and over)
Control Power +5V (1A and over)
Output Current Maximum 8A peak
Continuous 5A peak (at motor stops 4.5A peak)
Control Output stage Non-switching (linear) inverter Sine-wave current control
Control mode ・PLL (Phase-Locked Loop) control Synchronization with clocking (line driver), Pulse frequency dividing function*2
・Torque (current) control, Analogue voltage dispatching(±10V)
Input Rotation & direction command, Resetting, etc.
Output Encoder pulse (A,B,Z phase), PLL locking, Motor stop, Alarm etc.
Rotation inconsistency 0.001% and below*3
Abnormality detection The following are displayed at 7segLED
・Emergency stop (Air pressure abnormality)
・Initial operation time-out
・Rotation direction abnormality
・Motor overheat
・Driver overheat
・Power abnormality
When abnormality occurs Dynamic break (Built-in resistance)
Ambient environment Temperature:0 - 40 °C (32-104 °F)
Humidity:85% and below ,make sure there is no dew
Do not place the product in a harmful environment such as corrosive gas, metal powder, water, or oil, etc. for electric circuit.
Storage temperature -15 - 80°C (5-176°F)Make sure there is no dew
Cooling system Air cooling (Built-in cooling fan)
Mass 3kg
  • Application is to be judged for each product.
  • Used when dividing precision of encoder pulse is insufficient.
  • It could be 0.001% depending on load or rotation speed.


ShinMaywa Industries, Ltd.
Automatic Machinery Group, Wire Processing Systems Department
1-1 Shinmeiwa-cho, Takarazuka-shi, Hyogo 665-0052  Japan
Phone: +81-798-54-1834