Cooper DCM 460 User Manual

DCM 460 VOLTAGE BRIDGE AMPLIFIER

Description

The DCM 460 Bridgesensor is a self-contained, AC powered, signal conditioning module for bridge type
instrumentation. It contains a precision differential instrumentation amplifier with filtered output and a highly
regulated, low noise, adjustable output bridge excitation source. The unit is completely encapsulated for use in
rugged environments. The output filter cutoff frequency is 2000Hz and may be lowered by adding two external
capacitors.

Features

• 2 kHz Frequency Response

• Rugged, Compact And Fully Encapsulated

• Complete System-just Add AC Power

• Ready To Use With Screwdriver Wiring

• Stable and Accurate

Applications

• Weighing With Load Cells

• Long Term Structural Monitoring

• Process Control Pressure Transducers

• Temperature Controls Using Thermocouples

• Strain Measurements

Figure 1. Simplified Block Diagram

CF 28 1 4/2001

Specifications

(Typical @ 25°C unless noted)

Amplifier

Gain Range 40-250
Gain Temperature Coefficient 200 ppm/°C
Drift (RTI) 3 µV/°C
Input Bias Current ±30 nA

Input Impedance

Differential
Common Mode

Output Noise (RTO)

At gain=100
1 Hz to 2 kHz

Input Noise

Line Frequencies

Output Offset-Tare

Range
Drift

Common Mode Rejection

Gain=40 (DC-60 Hz)
Gain=250 (DC-60 Hz)
Rated Output (2k load) ±10V

Output Impedance

DC to 2 kHz

Dynamic Response

DC to –3 dB two pole
Bessel Filter
Common Mode Input Voltage ±6.5V
Bridge Supply
Input 115 VAC ±10% 50 to 60 Hz

Output Voltage 4 to 15 Volts
Output Current 120 mA

(see output voltage vs. current curve)
Load & Line Regulation 0.05%
VOUT=12V, IL=0 to 100 mA
Output Noise 0.5 mV RMS
Drift 200 ppm/°C max.
B+ Potentiometer Hysteresis 0.3% of output max.
Short Circuit Current 750 mA
Line Isolation 1,500 VDC
Mechanical
Operating Temperature 0°C to 70°C
Storage Temperature -25°C to +85°C
Weight 18 oz. (510 grams)
Size 3.75”L x 2.0”W x 2.87”H

3,000 megohms
6 megohms

2 mV P-P

15 µV P-P

-5V to +2V
±0.2 mV/°C

90 dB
100 dB

0.01 ohms to 1 ohm

2 kHz

(100, 220 & 230 VAC available)

9.53 x 5.1 x 7.62 (cm)

Getting Started with the DCM 460

I. Hook Up Procedure

A. Connect the +out of your load cell to the +INPUT, pin 8.
B. Connect the -out of your load cell to the -INPUT, pin 9.

Note: If the ± SENSE are not used in your load cell application, the connections in step C & D need to be
followed. If the ±SENSE are going to be used, do not jumper them as described in steps C & D.

C. Connect B+, pin 4, to the + excitation of your load cell and jumper the + SENSE, pin 3, to B+, pin 4.
D. Connect B-, pin 2, to the -excitation of your load cell and jumper the - SENSE, pin 1, to B -, pin 2.
E. Connect the VAC power supply to the AC input lines, pins 6 and 7.

II. Turn On Procedure

A. Verify that the hook up procedure is complete.
B. Verify the correct AC voltage is applied to the DCM 460; i.e. 100, 115, 220, 230.

CF 28 2 4/2001