Term - DC Motor
From VEX Wiki
An electric rotating machine energized by direct durrent (DC) and used to convert electric energy to mechanical energy.
Motors can have very different characteristics depending on their manufacture.
When a voltage is applied to the motor, it outputs a torque inversely proportional to its speed. (That means the faster the motor is going the LESS torque it outputs, and the slower the motor is going the MORE torque it outputs.) The motor will also draw current proportional to this torque (more torque means more current draw).
You can think of the motor as working to overcome a load. With NO load on the motor, it will spin very fast and draw almost no current. As the load increases on the motor it must output more torque to overcome the load, and as it increases the torque it draws more current. Eventually if enough load is placed on the motor, it will stop moving or “stall."
There are four main characteristics which define DC motor performance and define the relationships described above:
- Stall Torque (N*m): The amount of load placed on a motor which will cause it to stop moving.
- Free Speed (RPM): The maximum rotational speed a motor will run at when it is under no load.
- Stall Current (Amp): The amount of current a motor will draw when it is stalled.
- Free Current (Amp): The amount of current a motor will draw when it is under no load.
These four characteristics change proportionally depending on how much voltage is applied to the motor.
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