DayTronic 3000 series, 3178 Instruction Manual

MODEL

3178

STRAIN GAGE CONDITIONER

SB.5.1

INSTRUCTION MANUAL

3000

Instrument Series

Copyright © 1996, Daytronic Corporation. All rights reserved.

No part of this document may be reprinted, reproduced, or used in any form or by
any electronic, mechanical, or other means, including photocopying and recording,
or in any information storage and retrieval system, without permission in writing
from Daytronic Corporation. All specifications are subject to change without notice.

Correction

1

A

2

B

3
4

C

9

A

D

B

C

+EXC

–EXC

+SENSE

–SENSE

+SIG

–SIG

CAL SENSE

C

.
.
.

A

Extra Wire, paired
with CAL SENSE,
unconnected at
Connector A

SHIELD

1

A

2

B

3
4

C

9

D

A

B

C

+EXC

–EXC

+SENSE

–SENSE

+SIG

–SIG

CAL SENSE

B

.
.
.

A

Extra Wire, paired
with CAL SENSE,
unconnected at
Connector A

SHIELD

1

A

2

B

3
4
7

E

B

C

D

E

+EXC

–SENSE

+SIG

–SIG

LEBOW CAL

D

.
.
.

A

Extra Wire, paired
with LEBOW CAL,
unconnected at
Connector A and
at transducer

SHIELD

A

–EXC

+SENSE

to Model 3178 Instruction Manual, v. SB.5.1

The I/O Wiring Data in Fig. 4 of this manual does not give the correct shield pairing of
cable wires, which is shown in the revised diagrams below and on the following page:

Daytronic 400 Series

Transducer Connections

Lebow 1600 Series

Rotary Transformer Torque

Transducer Connections

Daytronic 500 Series

Transducer Connections

(cont’d)

Correction

+SENSE

–EXC

–SENSE

+SIG –SIG

CAL
SENSE

1

A

2

B

3

C

4
9

.
.
.

A

SHIELD

+EXC

+SENSE

–EXC

–SENSE

+SIG –SIG

CAL
SENSE

1
A
2
B
3
C
4
9

.
.
.

A

SHIELD

Extra Wire, paired with CAL SENSE,
unconnected at Connector A

+EXC

+SENSE

–EXC

+SIG –SIG

CAL
SENSE

1

A

2

B

3

C

4
9

.
.
.

A

SHIELD

Extra Wire, paired with CAL SENSE,
unconnected at Connector A

–SENSE

+EXC

to Model 3178 Instruction Manual, v. SB.5.1 (cont’d)

Daytronic 3X78 Instrument to Generalized Strain Gage Transducer

Showing CAL SENSE Connection

4-Wire Configuration for Cables
Shorter Than 20 Feet

6-Wire Configuration for Cables
Shorter Than 20 Feet

8-Wire Configuration for Cables
Longer Than 20 Feet

Model 3178 Instruction Manual, v. SB.5.1

Pub. No. 3178M.5.1, Issued 03/01

MODEL

3178

STRAIN GAGE CONDITIONER

INSTRUCTION MANUAL

Part No. 91121

Daytronic Corporation

Dayton, OH • Tel [phone]

www.daytronic.com

This page intentionally blank.

Daytronic Corporation

TABLE OF CONTENTS

Section

Page

1

Description

.................................................

1

2

Installation and Cabling

......................................

3

3

Calibration

.................................................. 11

4

Block Diagram Description 14

5

Verification of Normal Operation

19

LIST OF ILLUSTRATIONS

Figure

Page

1 Model 3178 Strain Gage Conditioner

1

2

Instrument Mounting Dimensions

4

3

Instrument Panel Mounting

5

4 I/O Wiring

9

5

Front Panel Description

12

6

Block Diagram

..............................................

17

7

Star Bridge Construction

20

LIST OF TABLES

Table

Page

1

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2

PLEASE NOTE: Sections 6 and 7, Figures 8 and

9, and Table 2 have been

removed from this manual.
If you need information regarding specific 3178 components and circuitry,

please contact the Daytronic Service Department at [phone].

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Daytronic Corporation

INSTRUCTION MANUAL

MODEL 3178 STRAIN GAGE CONDITIONER

1. DESCRIPTION

The Model 3178 is a conditioner-amplifier for use with resistance strain gage

transducers in applications which require an ac excitation voltage. It supplies a 3.28

kHz

precision amplitude-regulated excitation, remotely sensed, to the transducer.
The instrument uses a phase-sensitive carrier amplifier-demodulator design so that
both direction and magnitude of the applied force are determined. The 3178 con­tains the necessary balancing and calibration controls and conditions/amplifies the

applied input to a standard Five-Volt Data Signal Level which is the output analog

signal level of 3000 Series Instruments. Two analog outputs, having low-pass cutoff

frequencies of 2 Hz and 400 Hz, are provided. The filtered outputs provide for

averaging or smoothing of signals containing noise or other unwanted dynamic
components which are periodic in nature. Filtering removes these dynamic compo-

nents so that stable digital indication and precise jitter-free

precise jitter-free

control action can be

obtained. The Model 3178 is shown in Figure 1 and the specifications are given in

Table 1.

Figure 1. Model 3178 Strain Gage Conditioner

1

Table 1. Specifications

Model 3178

Transducers:

4-arm bridges, 90

to

1000 ohms. nominally 0.5

mv/v to

5

mv/v,

full scale.

Cables:

4-, 5-,

or 7-wire, depending on application; 1000

feet

maximum length.

Bridge Excitation: Regulated 3.28

kHz

ac; nominally 2

vac.

Balance Adjustments:

10-turn

coarse and fine; will balance 1.5

mv/v

initial unbalance.

Span Adjustments:

10-turn

coarse and fine; 0.5 to 5

mv/volt,

full scale.

Analog Outputs: Two

analog

outputs

available; 0 to ±5 volts

with

50%

overrange, 5 milliamperes maximum.

Bandpass

is dc to 2 Hz or dc to

400 Hz.

Active

low-pass filters provide for

rolloff

of 60 dB per decade

above cutoff frequency. Full-scale slew time is

1.4/f

seconds, where f

is

the

cutoff frequency.

Output Ripple and Noise: 0.15% of full scale (rms) maximum for

400-Hz output;

0.02% of full scale (rms) on

2-Hz output.

Accuracy: 0.05% of full scale.

Dimensions: 1.7 x 4.41 x 8.5 (HWD inches).

Operating Temperature Range: 0

to +130 degrees F.

Power Requirements: 105 to 135 volts

ac,

50 to 400 Hz at 5

watts

maximum.

2