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The electrical system, Type "k" dc lvdt – Warner Electric B30 Single Range Tensioncells User Manual

Page 4

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Warner Electric • 800-825-9050

P-2012-4 • 819-0404

For our discussion here, deflection of the Load
Plate toward the Base Block is defined as the
"Compression Mode", while the opposite is
defined as the "Tension Mode". Tensioncells are
designed to operate equally well in either mode.

The Base Block contains an integral Mechanical
Stop to limit the amount of deflection in either
direction, and a Viscous Damper to allow
control of the tensioncell response to rapid
changes in apparent tension loads. (See Page 3,
Figure 2)

The Electrical System

The electrical system consists of a Linear
Variable Differential Transformer (LVDT) which
converts the mechanical deflection of the Load
Plate into a useful electrical output signal. (See
Figure 3.) The movable core of the LVDT is
mechanically coupled to the Load Plate by
means of the Core Adjust Assembly. (See
Figure 3) This adjustment is factory set and is
not accessible.

Black - (2)

Red + (1)

Green (3)

Blue (4)

Input

Output

X Twisted Leads

A B

Oscillator

Demodulator

P1

S1

S2

X

X

When Supplied

with Cable

(1) Red + DC
(2) Black – DC

(3) Green – Signal
(4) White + Signal

C D

B
A

C
D

Figure 3

Type "K" DC LVDT

As illustrated in Figure 3, a DC LVDT consists of
the following components:

An oscillator, which converts the DC input
voltage into a high frequency alternating
current for exciting the primary coil (P1)

A Primary Coil (P1)

A movable, permeable metallic core

Two Secondary Coils (S1 and S2)

A demodulator and summing network to
rectify and integrate the currents from the
Secondary Coils