N123-134 Series
Exciter/Demodulator
N123-134 Exciter/Demodulator:This Snap Trac module contains a power
oscillator and a demodulator for use with LVDT’s, synchros and other carrier
excited, amplitude modulated, transducers. Carrier frequencies can be set
from 100 to 10,000 Hz.
SPECIFICATIONS
Input
Differential input across terminals
10 and 11.
AC input signal level should
be from .07 to 7.0 Vrms for
±10 VDC output.
Input impedance can be assumed
to be 40K
Ω
(with standard
values of R30, R31, R32, and R33).
Outputs
Excitation Output:
Frequency varies with C3, C4,
and R3.
As shipped: Freq. varies
100 to 2,000 Hz
Remove C3—Freq. varies 500
to 10,000 Hz
Amplitude—2 to 11 V p-p
Stability—amplitude varies
≤
250 ppm/°C
Demodulator Output:
to ±10 VDC nominal at Terminal 12
Ripple: < 40 mV p-p at
≥
carrier freq.
Linearity:
≤
±0.2% at 1.2 kHz
Stability:
≤
250 ppm gain/°C
±0.1 mV/°C
Polarity: Output at terminal
12 is negative when voltage at
terminal 11 is in phase with
terminal 3
Load Impedance: > 5K
Ω
FEATURES
Construction
➢
Plug-in connectors for quick installation of board.
➢
Test points on all critical signals for easy system setup.
➢
Component standoffs on all user-configurable components.
➢
Twenty-turn potentiometers for all adjustable controls.
➢
Rugged construction with solder mask for reliability.
SPECIFICATIONS
Demodulator Gain: General
expression for gain of the DC voltage
at terminal 12 assuming R33=R32,
R31=R30 and R34 fully CW
(i.e. max span setting)
R
32
R
37
R
45
e
12
=1.41*
*1+ *
(e
11
-e
10
) VDC
R
30
R
38
R
39
where e
10
and e
11
are Vrms
Differential Amplifier Gain:
Vout =
R
32
(e
10
-e
11
)
R
30
Frequency Response: Phase lag of
demodulator output signal increases
linearly from 0˚ to 180˚ as frequency
of modulation increases from zero to
the carrier frequency.
Temperature Range:
-20˚C to 50˚C (-4˚F to 122˚F)
Power Required:
±E: ±15 VDC reg, 3-wire @ ±50 mA
at pin-6, 7 & 8
±V: ±15 VDC to ±22 VDC unreg @
±40 mA, 3-wire at pin-1, 2 & 9
(or 7)
This power is available from the
Model N121-132A Snap Trac
Servocontroller.
( )
MOUNTING HARDWARE
➢
PVC Snap Trac, Part Number 65419-1
DIMENSIONS
Exciter/Demodulator: 3.25 in x 6.00 in long
Maximum Component Height: 2.42 in
R31
R24
R42
R44
R45
R40
R16
R22
R23
R39
R27
R37
R30
R14
R13
R17
R9
R10
R18
R12
R21
R5
R8
R25
R26
R41
R4
R35
R19
R2
R28
R36
R29
R38
R15
R1
R11
R20
R43
R34
R7
R3
R6
C13
C12
C10
C8
C6
C11
D4
D6
D5
D1
D7
D2
D3
SAMPLE
TP3
TP12
TP7
VIN
U4
J1
U2
U5
U3
U6
U1
Q1
Q2
ZER
O
AMP
SP
AN
PHASE
FREQ
C16
C3
C4
C17
R33
C14
C
15
C1
C2
Q3
R32
12
11
123
4
5
678
9
1
0
MADE IN USA
MODEL:N123-134
SN:
