5725A

Instruction Manual

4-21. Fan Supply Section

The fan supply uses the same transformer secondary windings as the ±15 and ±20V supplies. Its own full-wave bridge rectifier diodes create a supply voltage of +25V. Transistor Q351 is operated near saturation, and provides the measurement point to tell the CPU whether the fan is running. The output of Q351 is sent to the analog multiplexer on line -FAN to accomplish this.

4-22. Digital Assembly (A5)

From a software standpoint, digital circuitry functions as a subset of the 5700A in-guard CPU. Digital circuitry resides on three assemblies within the 5725A: the Digital assembly (A5), the High Voltage Sense assembly (A6), and the Current Amplifier assembly (A2). All the 5725A hardware, including digital, is in-guard, except for the guard crossing and the CABLEOFF detection circuit.

Figure 4-2 is a block diagram of the Digital assembly. The Digital assembly contains most of the digital circuitry, including the following:

∙Microcomputer (Hitachi 6303Y CMOS)

∙External RAM (CMOS static)

∙External ROM

∙EEROM (2Kb X 8)

∙Break-detect circuitry

∙Power up and reset circuitry

∙Watchdog timer circuitry

∙Front panel LEDs

∙LED decoder and driver

The High Voltage Sense assembly (A6) contains the optoisolator link (guard crossing) to the 5700A Main CPU and the CABLEOFF circuit.

The Current Amplifier assembly (A2) contains the interface to the digital bus (two latches and three relay drivers) and a relay driver chip.

4-23. Microcomputer

The 6303Y CMOS microcomputer is configured for Mode 1 operation, with external RAM and external ROM. Port 3 provides a common data bus (D00-D07), while port 1 and bits 0 through 5 of port 4 provide the address bus (A0-A13). Bits 6 and 7 of port 4 are address lines A14 and A15.

4-24. External RAM.

External RAM is enabled whenever A15 is high, A14 is low (hex 8000-BFFF), and either RD* or WR* is true. Reading and writing is controlled by bit 2 of port 7.

4-25. External ROM

The external ROM (U515) is enabled via ROMSEL* whenever A15 and A14 are high (hex C000-FFFF). Bit 0 of Port 7 (RD*) is OUTPUT ENABLE*.

4-16

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Fluke 5725A instruction manual Fan Supply Section, Digital Assembly A5, Microcomputer, External RAM, External ROM
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5725A specifications

The Fluke 5725A is a high-performance, multifunctional temperature calibration source designed to meet the demanding requirements of laboratory and industrial environments. Renowned for its accuracy, reliability, and versatility, the 5725A serves as a powerful tool for engineers and technicians engaged in temperature calibration processes.

At the core of the 5725A is its advanced measurement technology, which allows for precision temperature calibrations across a wide range. With an operating temperature range from -200°C to 660°C, it caters to various applications, making it suitable for calibrating thermocouples, resistance temperature detectors (RTDs), and other temperature measurement devices.

One of the standout features of the Fluke 5725A is its outstanding accuracy, boasting a specified uncertainty of just ±0.15°C. This level of precision ensures that users can maintain compliance with regulatory standards and regulatory requirements in fields such as aerospace, pharmaceuticals, and manufacturing.

The Fluke 5725A is equipped with dual-channel capabilities, allowing users to calibrate two devices simultaneously. This enhances productivity by minimizing downtime and optimizing workflow efficiency. The intuitive touchscreen interface simplifies operations, enabling users to view measurements, set up test parameters, and access historical data with ease.

Versatile connectivity options such as USB and Ethernet enable seamless integration into existing systems and allow for data transfer, remote control, and configuration. This feature empowers technicians to conduct calibrations efficiently, whether on-site or remotely.

The robust design of the Fluke 5725A ensures its durability in demanding environments. Built with high-quality materials, it is resistant to shocks and vibrations, making it suitable for use in manufacturing plants and laboratories where equipment may be subjected to harsh conditions.

Another notable characteristic of the 5725A is its ability to generate stable temperature outputs with minimal drift, contributing to consistency in calibration results. Its built-in self-test functionality helps ensure that the unit remains in peak operating condition, giving users confidence in their calibration processes.

In summary, the Fluke 5725A is a top-tier temperature calibration source that excels in accuracy, reliability, and user-friendliness. Whether in laboratory settings or industrial applications, its advanced technologies and features make it an essential tool for professionals tasked with maintaining precision in temperature measurements.
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