Transducer Principle; Half-Bridge Transducer; Fig. 9-3: Half-Bridge Transducer - Addi-Data APCI-3701 Technical Description

APCI-3701
9.5

Transducer principle

The inductive transducer is basically used for precise measuring travels. It is a
travel/voltage sensor, the output voltage of which changes linearly along with the
moving ferromagnetic core. The ferromagnetic core moves according to a straight
line in a transformator, which consists of a central primary coil and 2 external
secondary coils (cylindrical windings). The power buffer provides an AC voltage
source to the primary coil. This enables the secondary voltage to be supplied and
to change according to the position of the magnetic core.

9.5.1 Half-bridge transducer

The half bridge transducer features 2 inductive coils (windings). These are
directly fed with 2 sinusoidal voltage signals (a positive oscillator voltage and a
negative oscillator voltage). The measuring bolt moves along the 2 coils with a
ferromagnetic core which changes the voltages in the two coils depending on its
position.
The measuring bolt functions like a variable voltage distributor and the change in
voltage at the coils results in the sinusoidal measuring signal to be evaluated.

Fig. 9-3: Half-bridge transducer

Functions of the board
43