5725A

Instruction Manual

4-40. High Voltage Amplifier (A3)

The High Voltage Amplifier assembly, operating with the step-up signal transformers, constitutes an amplifier with an inverting gain of 100. It amplifies 2.2V to 11V signals from the 5700A Oscillator and returns 220V to 1100V to the 5700A where they go to the 5700A OUTPUT HI/OUTPUT LO binding posts. The signals to and from the 5700A come through the High Voltage Sense assembly (A6) where they are switched.

The High Voltage Amplifier assembly consists of an input amplifier, integrator, window comparator, input clamp, transconductance and cascode stage, midstage, midstage -400V filter, high voltage heat sink assemblies, autobias current source, autobias sense circuit, high voltage amplifier feedback, and temperature monitoring circuits.

The High Voltage Amplifier drives the primary winding of the appropriate signal transformer depending on the frequency of operation. Signal transformers are interfaced to the High Voltage Amplifier via connector J604. Relays that select signal transformers are mentioned under the heading "Signal Transformers" further on.

The High Voltage Amplifier assembly uses the ±400V supplies from the Power Supply assembly. Lethal voltage appears on the heat sink assemblies. Do not open the 5725A cover without referring to the access procedures and warnings in Section 6.

Figure 4-4 is a block diagram of the High Voltage Amplifier assembly. Refer to the block diagram or the schematic to better understand theory of operation.

4-41. Input Amplifier

The input amplifier, U602, is an op amp whose input comes from HV IN on J653 through R623 and R621. HV IN is the 2.2V to 11V ac signal generated by the 5700A and routed through the High Voltage Sense assembly. The input amplifier has a high- frequency gain of 5.5, but because feedback resistor R622 is ac-coupled through C615, the gain is much higher at low frequencies. The inverting input of U602 is buffered with Q601. The nominal output of the input amplifier, LVAMP TP602, is about 6V dc.

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Fluke 5725A instruction manual High Voltage Amplifier A3, Input Amplifier

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.