Dynamic Brake Function - Mitsubishi Electric Melsec FX Series Beginners Manual

Components of Positioning Control and their Roles
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.
Main
circuit
AC power
supply
Fig. 3-8: Dynamic brake function
3 - 10
NFB
R
Converter
S
AC to DC
T
Position
Deviation
controller
counter
Number of
rotations of motor
Power: OFF
Contacts of dynamic brake: ON
Servo Amplifier and Servo Motor
Inverter
DC to AC
D/A
conversion
Motor stop characteristics when the
dynamic brake is actuated
When the dynamic brake
is not actuated
U
V
SM PLG
W
These contacts of the
dynamic brake turn ON
when the power is
interrupted.
Time
325010da.eps
MITSUBISHI ELECTRIC