Industrial 3000RPM YASKAWA AC Servo Motor 50W 200V 0.6A SGMAH-A5A1A-YB11

Overload Protection
Overload protection is installed in the motor circuit and/or motor to protect the motor from damage from mechanical overload conditions when it is operating/running.
The effect of an overload is an excessive rise in temperature in the motor windings due to current higher than full load current.
Properly sized overload protection disconnects the motor from the power supply when the heat generated in the motor circuit or windings
approaches a damaging level for any reason.

The larger the overload, the more quickly the temperature will increase to a point that is damaging to the insulation and lubrication of the motor.

Unipolar vs. Bipolar
Unipolar drivers, always energize the phases in the same way. One lead, the "common" lead, will always be negative.
The other lead will always be positive. Unipolar drivers can be implemented with simple transistor circuitry. Thedisadvantage is that there is less available torque because only half of the coils can be energized at a time.
Bipolar drivers use H-bridge circuitry to actually reverse the current flow through the phases. By energizing the phaseswith alternating the polarity, all the coils can be put to work turning the motor.
A two phase bipolar motor has 2 groups of coils. A 4 phase unipolar motor has 4. A 2-phase bipolar motor will have 4wires - 2 for each phase. Some motors come with flexible wiring that allows you to run the motor as either bipolar orunipolar.

Coils and Phases
A stepper motor may have any number of coils. But these are connected in groups called "phases". All the coils in a phase are energized together.

OTHER SUPERIOR PRODUCTS