cd72
nel Operation
¨
Regulated Against Power Variations
DESCRIPTION
The CD72 Carrier Demodulator is a complete Multichannel
system in a small package for OEM Applications. Using the
latest integrated circuit techniques, this unit supplies a 5
volt, 5 kHz carrier excitation for Variable Reluctance and
Variable Differential Transformer Transducers,
demodulates and amplifies their outputs to provide a ±10
Vdc signal for static and dynamic measurements.
Available in either two (2) channel or four (4) channel
configurations. The CD72 consists of an interconnecting
"mother board" and either three (3) or five (5) plug-in circuit
boards. One circuit card contains the oscillator power
supply, which supplies the carrier excitation to the
transducers and ±15 Vdc to power the carrier
demodulators. The remaining circuit cards are the carrier
demodulator boards.
The Carrier Demodulator Card amplifies and demodulates
the transducer output signal to ±10 Vdc which is
proportional to the stimulus applied to the transducer. Each
card has a screwdriver adjustment for zero and span
control.
Low input impedance allows for operation with transducers
at a distance of over a thousand (1000) feet from the
carrier demodulator with no degradation of signal.
An active filter on the output provides the CD72 with a flat
frequency response from steady state to 1000 Hz.
Both input and output are protected against short circuit.
Specifications
Input Sensitivity:
Min. 12 mV/V for ±10 Vdc
output continuously
adjustable by span control
Maximum Input:
2.5 Vrms, 5 kHz
Bridge Excitation:
5 Vrms, 5 kHz
Bridge Configuration:
2 arm variable reluctance
transducers LVDT
Zero Control:
±10 mV/V
Output:
0 to ±10 Vdc; 10 mA into 1k
ohm load, protected against
short circuit
Output Ripple:
Less than 10 mV peak to
peak, max
Output Impedance:
10 ohms maximum
Frequency Response:
Flat to 1000 Hz
Linearity:
±0.05%
Stability:
±0.1% long term
Temperature Range:
0 to 185°F
Thermal Effects:
Zero: 0.5%/100°F
Span: 1%/100°F
Oscillator Power Suppy
Carrier:
5 Vrms, ±1%, 5 kHz
D.C. Power:
±15 Vdc to operate either
the 2 or 4 channel system
A.C. Power Required:
95 to 125 Vac, 50 to 400 Hz,
3 VA (205 to 250 Vac by
internal connection change)
Ordering Information
Spare Parts Information
CD72-2
For two channel system consisting of:
1 Mother Board
1 Oscillator Power Supply Board
2 Carrier Demodulator Boards
Mother Board:
CD72-2 P/N 7347
CD72-4 P/N 7775
CD72-4
For four channel system consisting of:
1 Mother Board
1 oscillator Power Supply Board
4 Carrier Demodulator Boards
Carrier Demodulator Boards: P/N 7344-1
Oscillator Power Supply: P/N 9617
Carrier Demodulator
CD72-2 AND 4 SCHEMATIC TYPCIAL CONNECTION
8626 Wilbur Avenue - Northridge, CA 91324-4498
(818) 886-2057 - FAX (818) 886-6512
http://www.validyne.com
-
e-mail to sales@validyne.com
TRANSDUCER CONN.
POWER INPUT 117 VAC WK-4 (CANNON)
GUARD
N.C
TRANSDUCER
INPUT A
TRANSDUCER CIRCUIT BD. CONNECTOR
INPUT B TRANSDUCER INPUT SGR-15-SRXB
COMMON WIRING DIAGRAM
OUTPUT A
OUTPUT B CIRCUIT BD CONNECTOR
N.C SGR 15- SRXB (MASTERITE)
N.C (FURNISHED)
CONNECTOR WIRING DIAGRAM
73
5.00
7.5 3.625 3.70 .25
±.010
3.63
3.80 3.125
±.010
CARRIER DEMODULATOR CIRCUIT BD
TRANSDUCER NPUT A OUTPUT A SWAGE STANDOFF
CIRCIUT BD CONNECTOR THREADED
SGR-15-SRXB
CARRIER DEMODULATOR CIRCUIT BD.
6-32NC-28 THRU
TRANSDUCER INPUT B OUTPUT B
4 PLACES
ZERO CONTROL
SPAN CONTROL
POTENTIOMETER
POTENTIOMETER
CD72-2
POWER INPUT POWER INPUT TRANSDUCER CONN
117 VAC 117 VAC
GUARD GUARD
NC NC
GRD - 15V
NC
+ 15V
OUTPUT C OUTPUT A
COMMON COMMON
OUTPUT D OUTPUT B
TRANSDUCER TRANSD UCER
CKT BD. CONN
INPUT C INPUT A
TRANSDUCER INPUT
WIRING DIAGRAM
TRANSDUCER TRANSDUCER
INPUT D INPUT B
CONNECTOR WIRING DIAGRAM
CIRCUIT BD CONNECTOR
00-6007-030-450-018 (ELCO)
.73 5.00
3.70
.25 TYP.
.75 3.625
±.010
CIRCUIT BD. CONN.
STANDOFF SWAGE
6-32 NC -2B THRU
4 PLACES AS SHOWN
CARRIER DEMODULATOR
CIRCUIT BOARDS
4.900
±.010
INPUT A
5.40
OUTPUT A
INPUT B
OUTPUT B
TRANSDUCERS
INPUT C
OUTPUT C
OUTPU T D
OUTPUT D
ZERO CONTROL
SPAN CONTROL
POTENTIOMETER
POTENTIOMETER
TYP 4 PLACES
TYP. 4 PLACES
CD72-4