tachometer

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tachometer

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Iconic Diagrams\Mechanical\Rotation\Sensors

Use

Domains: Continuous/Discrete. Size: 1-D. Kind: Iconic Diagrams (Rotation) / Block Diagrams.

Description

A tachometer is a transducer for measuring the rotation speed. It is normally mounted at the shaft of a motor and gives a voltage signal proportional to the rotation speed:

Tachometer1

with Kv the tachometer gradient [V / rad/s] and v the shaft velocity [rad/s]. This equation represents the ideal case. Due to the slots and commutator segments of the tachometer, a noise ripple will exists:

Tachometer2

with N the ripple frequency [cycles per turn] and Kn the peak to peak noise Ripple [in % of the output voltage]. To convert the Voltage Gradient parameter from RPM units [V / RPM] to radian units [V / rad/s], use the conversion formula:

 

Tachometer3

Interface

Ports

Description

p

Rotation port.

Causality

 

fixed torque out

(The output torque is zero)

Outputs

Description

output

Output voltage [V]

Parameters

 

Kv

Kn

N

Voltage Gradient [ V / rad/s ].

Noise Ripple , relative to output voltage [%].

Ripple frequency in cycles per turn [].