Sensors

Thursday, November 21, 2024

Hermetically sealed resolver

Dual RVDT sensor

RVDT position sensor

Electric motor position sensors

An electric motor position sensor is a device used to detect and measure the angular or linear position of a moving component, typically the shaft of an electric motor. These sensors provide accurate information about the current position of the motor, which is essential for motor control in a variety of industrial, aerospace and military applications.

What is a resolver?

A resolver is a type of electromechanical transducer that measures angular position using sinusoidal and cosinusoidal signals. Resolvers are robust and highly accurate, often used in demanding environments.

What is an RVDT?

RVDT (Rotary Variable Differential Transformer) is a type of rotary position transducer that accurately measures the angle of rotation. It is similar in principle to the LVDT (Linear Variable Differential Transformer), but instead of measuring linear displacement, it measures angular displacement.

Main components of a motor position sensor

Stator

The stator is the fixed part of the position sensor. The stator contains the primary and secondary coils.

Rotor

The rotor is the moving part of the position sensor, mechanically coupled to the object whose angle of rotation is to be measured. The rotor modifies the inductive coupling between the stator coils.

Primary coils

The primary coils in the stator are energised by an alternating current source.

Secondary coils

The secondary coils, also located in the stator, induce a voltage that varies according to the position of the rotor.

How a motor position sensor works

Primary coil excitation

An alternating voltage (AC) is applied to the primary coil, generating an oscillating magnetic field.

Induction in the secondary coils

The rotor, in a variable position, influences the inductive coupling between the primary coil and the secondary coils. The angular displacement of the rotor modifies the magnitude of the voltages induced in the secondary coils.

Voltage difference

The secondary coils are arranged differentially, i.e. the voltages induced in each are opposite. The voltage difference between the two secondary coils is proportional to the angle of rotation of the rotor.

Output signal

The voltage difference is converted into an electrical signal proportional to the angle of rotation of the rotor, enabling the angular position to be measured accurately.

Resolver and RVDT position sensor applications

A resolver is an extremely reliable and accurate angular position sensor, widely used in demanding environments where robustness is crucial. Its operating principle, based on electromagnetic induction and sinusoidal transformation, makes it an indispensable tool for many industrial, aeronautical, automotive and military applications.

An RVDT is a highly accurate and reliable rotary position transducer used to measure angles of rotation in a variety of industrial, automotive, aerospace and robotic applications. Its robustness and non-contact nature make it an ideal choice for demanding environments where accurate angular position measurement is crucial.

SERMAT

SERMAT
249, rue de la Garenne
92000 NANTERRE, FRANCE
FR
+33 1 46 52 68 68
contact@sermataero.fr