Example
Direct current motors (DC-motors)
- Up to 98% efficiency
- Power cord or battery
Brush motor:
- cheap
- Mature technology
- Sparking / high-frequency interferences
- Life limit – carbon brushes
Brushless motor:
- More efficient / less heat
- Less wear
- More power per weight
- Requires a controller
Stepper Motors
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Revolutions will be made in an amount of steps (degree), not as a constant movement, exact positions can be achieved
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Bipolar: 2 coils 4 connections (more power per motor-volume)
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Unipolar: at least 5 connections, simpler control
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Reluctance motor
- toothed soft iron structured rotor
- No permanent magnets
- Free magnetic flow, no magnetic field after switched off
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Permanentmagnet motor
- Permanentmagnet on the shaft / Stator made of soft iron
- Moment of rest
- Lower resolution in comparison to ther reluktance motor
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Hybridmotor
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Permanentmagnet and toothed soft iron core on the shaft
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Servos
- Analog servos
- Low power consumption
- Low price
- Digital servos
- Faster positioning time
- Higher resolution
- Partly programmable
- PWM-control
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Common for hobby servos
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Servo elektronics regulate the actor (potentiometer) against the motor position
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The pulse width of the control signal regulates the target position
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Various variations on pulse widths and travel ranges
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