Mitsubishi Electronics A172SH Sleep Apnea Machine User Manual


 
Positioning Control Components of Positioning Control and Their Roles 3
3-8
3.2.4 Regenerative brake function
During deceleration, because the servo motor rotates by the load inertia of the drive
mechanism, it functions as a generator and electric power returns to the servo amplifier.
The regenerative resistor absorbs this electric power, and functions as a brake (called a
regenerative brake.)
The regenerative brake is required to prevent regenerative over voltage in the servo
amplifier when the load inertia is large and the operation is frequently performed.
The regenerative resistor is required when the regenerative power generation quantity
during deceleration exceeds the allowable regenerative electric power of the servo
amplifier.
3.2.5 Dynamic brake function
When a circuit inside the servo amplifier is disabled by a power interruption in the AC power
of the main circuit or actuation of the protective circuit, the terminals of the servo motor are
short-circuited via resistors, the rotation energy is consumed as heat, then the motor
immediately stops without free run.
When the motor stops by elimination of the rotation energy, the brake is not effective and
the motor runs freely.
Power: OFF
Contacts of dynamic brake: ON
Motor stop characteristics when the
dynamic brake is actuated
Number of
rotations of motor
Time
When the dynamic brake
is not actuated
Converter
AC DC
S
R
T
NFB
Deviation
counter
D/A
conversion
Position
controller
Main
circuit
AC power
supply
V
U
W
These contacts of the
dynamic brake turn ON
when the power is
interrupted.
SM PLG
Inverter
DC AC