Cooper Instruments DCM162 Installation Manual

DCM 162

BRIDGESENSOR

USER’S GUIDE

www.cooperinstruments.com

PH: 540-349-4746 FAX: [phone]

CONTENTS

Features....................................................................................................................................... 1

Description.................................................................................................................................. 1

DCM 162 vs. DCM 160 ................................................................................................................ 1

DCM 162 Schematic.................................................................................................................... 1

Specifications ............................................................................................................................. 2

Functional Description............................................................................................................... 3

Instrumentation Amplifier .......................................................................................................... 3

Active Filter ................................................................................................................................. 4

Bridge Supply ............................................................................................................................. 5

Half Bridge Completion/Bridge Balance................................................................................... 5

General Calibration Procedures................................................................................................ 5

Application Examples ................................................................................................................ 6

Mechanical Specifications ......................................................................................................... 7

Warranty Repair Policy .............................................................................................................. 8

CF 118 ii DCM 162 - 4/2001

Features

• Pin for Pin Replacement for DCM 160.

• Compact, complete and convenient to use

• Easy access to all trim adjustments

• Half Bridge applications made easy by Internal Completion Resistors

• On card Bridge Balance Trimpot eliminates additional wiring for Three Wire applications

• Changing Bridge supply voltage is easy using on board trimpot with adjustment range from +4 to +10 VDC

• Bridge supply lead resistance effects can be ignored with built-in remote sensing

• Filter frequency can be changed with the flick of a DIP switch

Description

The DCM 162 Bridgesensor is a complete signal conditioning system on a card designed expressly for either half or
full bridge transducers. The DCM 162 consists of a high performance instrumentation amplifier, a user adjustable
active filter, high stability bridge supply and all of the required circuitry, trimpots, etc., so that only point to point wir­ing need be made to the inputs, outputs and power to have a complete signal conditioning system up and running.

The mounting kit provides coarse and fine gain adjustment trimpots along with input and output offset adjustments,
DIP switches for setting the bridge supply output and active low pass filter cutoff frequency.

Application of the DCM 162 is easy by following the detailed applications information that is included with this data
sheet and full engineering specifications allow easy and complete worst-case analysis.

DCM 162 vs. DCM 160

The Model DCM 162 is a pin compatible replacement for the DCM 160, which is no longer available. The one
major difference is that the DCM 162 does not have a reference voltage on pin J. Pin J has no connection. The
DCM 162 also has a high frequency input filter to reduce EMI. This filter has a high frequency cutoff above
200KHz, which is well above the requirements of weighing systems. See Figure 3 DCM 162 Input Amp Response.
The output of the instrumentation amplifier, pin P, is not inverted with respect to the Filter Output as it was in the
DCM 160. The output offset pot, RP1, is disabled by a jumper, J1, which must be removed to use RP1. The
external output offset input, pin K, is always active.

Applications using the DCM 160 can use the DCM 162 simply by inserting the board and making the typical zero
and span adjustments. No wiring changes should be required.

DCM 162 Schematic

Figure 1. Complete schematic of the DCM 162 Bridgesensor

CF 118 1 DCM 162 - 4/2001