DMR35-DCV Series

Precision DC Voltmeter

DMR35-DCV.A01.D0

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OPERATION:

Measurement Type and Capabilities

The DMR35 series of digital voltmeters employ a precision ADC and a low-power microcontroller to measure DC voltage. These meters provide full-

scale measurement ranges spanning 5 volts to 50 volts for the DCV1 model, and ±5V to ±50 V for the DCV2 model. Both models present a 1MΩ input

impedance. These meters’ measurement systems supports a common-mode input voltage range of up to +/-48V with respect to the power supply

return (-VS connection), simplifying their application in a wide variety of systems

FRONT PANEL & FRONT PANEL LAYOUT AND FUNCTION

Bar-graph Display: The 21 segment bar-graph display responds quickly and smoothly like an

analog meter movement to aid in reading rapidly changing measurements.

Numeric Display: The 3-1/2 digit display provides precise measurements for steady-state and

slowly changing measurement values.

REAR PANEL LAYOUT AND SCREW TERMINAL CONNECTIONS

DMR35 meters provide four screw terminals for power and measurement connections, as well as a 5-position DIP switch for meter configuration, as

described below.

Rear Layout

Terminal #

Name

Function

1

+VS

Power supply input terminals (9-32 VDC)

2

-VS

3

+VIN

Voltage measurement input terminals

4

-VIN

DIP Switch: Five individual switches support display intensity settings (SW1-SW2)

and measurement range selection (SW3-SW5)

Note: It is important to tighten all screw-terminals to their torque specifications.

Proper tightening will help ensure reliable operation. Applications subject to

vibration should use stranded wire.

POWER SUPPLY CONNECTIONS

The meter is powered through the +VS and –VS terminals and requires a DC power supply that may range from 9VDC to 32VDC. This supply is

electrically isolated from the meter’s measurement electronics, so that the meter’s measurement input terminals (+VIN, -VIN) do not need to be

connected to the meter’s power return terminal (-VS), and may vary as much as +/-48V from this connection. Please note that the meter’s isolation

barrier is intended only to simplify measurements, and not for safety purposes – the maximum voltage between the power supply terminals (+VS or –

VS) and the measurement input terminals (+VIN, -VIN) must be limited to +/-48VDC. The DMR35 series of meters incorporates protection against

momentary applications of both overvoltage and reverse polarity to the power supply(+VS, -VS) terminals. Depending on regulatory and application

requirements it may also be necessary for the user to add external fusing.

MEASUREMENT INPUTS

Voltage to be measured by the DMR35 is applied to the +VIN and –VIN terminals. Unlike many panel meters, the DMR35 series’ measurement inputs

are electrically isolated from the power supply terminals, which allows for fully differential measurements over a common-mode range of +/-48V with

respect to the power supply terminals +VS or -VS. The input impedance between the –VIN to +VIN terminals is nominally 1 M

Ω.