Omega Multifunction Indicator-Simulator, CL526 manual Functional Description, Power supply

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4 FUNCTIONAL DESCRIPTION

The CL526 portable calibrator block diagram is shown below.

 

External battery

Ni-MH

 

 

charger

Batteries

 

A

Converters for

Power supply

Reference

backligh

junction

 

 

 

 

Rj signals

 

Display

 

Digital

 

 

interface

 

A

 

 

 

D/A

Microprocessor

Keyboard

 

(converter)

 

 

 

 

 

Signal OUT

 

 

 

output signal

Comparator

output signal

 

Gain Control

IN/OUT

 

and buffer

 

 

Switch

 

 

 

 

 

 

IN/OUT terminals

power supply

microprocessor (central unit + memory)

input circuit

cold junction compensator (Rj)

LCD display

operative keyboard

digital to analog converter

4.1Power supply

The instrument is powered, if not otherwise specified with the order, by four internal batteries that can be recharged through an external charger module supplied as a standard accessory.

The internal batteries are Ni-MH rechargeable AA type with a nominal voltage of 1.25 V. The jumper “J1” (mounted on the mother board), when soldered into the “B” position, allows the instrument to be powered by the four internal rechargeable batteries or, if needed, directly from the power line. The voltage of the four batteries in series (approximately 5V) is connected to the input of a hybrid circuit.

Pressing the <ON> key will provide the two levels of voltage for the circuitry of the instrument:

+5 V for logic and analog circuits - 5 V for analog circuits

The second section, on the power supply circuit, is configured as a voltage multiplier generating for the final output stage, a voltage of 24V dc. The above voltage levels are required to work with an external resistance of 1000maximum when in current simulation mode (20 mA - 20 V). During operative modes, other than current simulation a diode de-energizes the hybrid circuit reducing the overall power consumption.

Recommendations and instructions to convert the instrument for a power supply with normal alkaline batteries are described in par. 8.3.

4.2Keyboard

The front panel is a tactile polycarbonate membrane keyboard, and has a working life of one million operations per key. The contact closure of the membrane keyboard is acknowledged as a coded signal by the microprocessor that recognizes the operators instructions.

Keys are interconnected on a 4x3 matrix; the microprocessor identifies directly the active key.

The values of the <▲> and <▼> keys (membrane slidewires) are acknowledged through the converters built in the microprocessor chip.

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Contents CL526 OMEGAnetSM On-Line Service Internet e-mail Info@omega.com Introductory Note Table of Contents Digital Interface General Performance Specifications Battery life Power supplyBattery voltage Dimensions 120x60x230 mm Weights net 1 Kg32 to +302F ± 0.02% of rdg +0.18F Table of ranges and accuracyGeneral Features Case Physical Description Functional Description Power supply+ 5 V for logic and analog circuits 5 V for analog circuits Input circuit Firmware MicroprocessorDigital display Digital to analog converterResistance and Rtd measurements Battery charger. Operation from line sourceThermocouples input-output circuit Resistance and Rtd simulationUnpacking Out 1248.3C Tc PRE-OPERATIONAL CheckElectrical Connections Wiring practiceExamples of input /output wiring and connections Thermocouple wiresClass Limit of Error of thermocouple wiresBattery Charger Power SupplyHow to maximize the battery life Battery Line OpBattery voltage indication Power onOperating mode set up Operation & ApplicationsParameter or sensor selection OUT mode selection1032.2C TcK Out 0.0C TcKRj mode International Temperature ScaleTecnical unit Decimal point positionAverage readings Data memory configurationIN-OUT data memories Data memory automatic scanning Data memory manual recallAutomatic simulation cycle Manual step advanceSimulation cycle selection Start 0.0mV Time 0h 0m 50sEnd 100.0mV 0mVSimulation cycle Rj compensation mode checkScale factor program Mode Linear Mode SquareRJ 0.0C ext ProgWord psi Word hPa Word mbarFirmware version code Serial number Installation parameter procedureExternal Rj compensation Digital output wiring practice Digital interface data program modeDigital Interface Baud RateCommunication protocol from CL526 to a PC TTL to RS 232 adapterComputer CL526 Data InstructPage Ramp = OHM Computer request for CL526 settingsMode InstrDis/Lin STO 2 #D 127 202 Display Chksum = DATA1 + DATA2 + Data 3 + Data 4 .AND.7F Example a data transfer from CL526 to PC Communication programsExample B PC instructions to CL526 Example a3ØØ While LOC 1 = Ø Wend Safety recommendations MaintenanceFaulty operating conditions Error ChecksumStorage Protection fusesIndex WARRANTY/DISCLAIMER Temperature