Connecting the Sense Leads

You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the -S analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense leads are left open during operation, the supply will regulate at the output terminals instead of at the load. Remember to bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.

CV Regulation

The voltage load regulation specification in Table 1-3a applies at the output terminals of the power supply. When remote sensing, this specification must be compensated. Add an increment to the voltage load regulation specification as specified by “∆mV” in the equation given under Load regulation in Table 1-3b.

OVP Considerations

The OVP circuit senses the voltage near the output terminals and not at the sense terminals. Depending on the voltage drop between the output terminals and the load, the voltage sensed by the OVP circuit can be significantly higher than actually being regulated at the load. You must program the OVP trip high enough to compensate for the expected higher voltage at the output terminals.

Output Rating

The rated output voltage and current specification in Table 1-3a applies at the output terminals of the power supply. With remote sensing, any voltage dropped in the load leads causes the supply to increase the voltage at the output terminals so it can maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load, this forces the supply voltage at the output terminals to exceed the supply's rated output. This will not damage the supply, but may trip the OVP (overvoltage protection) circuit, which senses the voltage at the output bus bars. When operated beyond its rated output, the supply's performance specifications are not guaranteed, although typical performance may be good. If the excessive demand on the supply forces it to lose regulation, the Unr annunciator will indicate that the output is unregulated.

Output Noise

Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power supply. Do not use the shield as one of the sense conductors.

Note

The signal ground binding post on the rear panel is a convenient place to ground the sense shield.

Stability

Using remote sensing under unusual combinations of load-lead lengths and large load capacitances may cause your application to form a low-pass filter that becomes part of the voltage feedback loop. The extra phase shift created by this filter can degrade the supply's stability and result in poor transient response. In severe cases, this may cause output oscillations. To minimize this possibility, keep the load leads as short as possible and tie wrap them together.

In most cases, following the above guidelines will prevent problems associated with load lead inductance. However, if a large bypass capacitor is required at the load and load-lead length cannot be reduced, then a sense-lead bypass network may be needed to ensure stability (see Figure 4-4b). The voltage rating of the 33 ∝F capacitors should be about 50% greater than the anticipated load-lead drop. Addition of the 20-Ω resistors will cause a slight voltage rise at the remote sensing points. For utmost voltage programming accuracy, the supply should be recalibrated with the DVM at the remote sensing points (see “Appendix A - Calibration”).

Note

If you need help in solving a stability problem with any Series 667xA power supply contact an Agilent

 

Service Engineer through your local Agilent Sales and Support Offices.

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Agilent Technologies 664xA, 665xA, 667xA, 669xA, 668xA manual Connecting the Sense Leads

668xA, 669xA, 667xA, 664xA, 665xA specifications

Agilent Technologies has long been a pioneer in the production of high-performance electronic test and measurement instruments, particularly in the field of power sources. Among its notable offerings are the Agilent 667xA, 669xA, 665xA, 664xA, and 668xA series of power supplies. These instruments are designed to provide stable, reliable power for a variety of applications, including electronic testing, industrial processes, and research laboratories.

The Agilent 667xA series is characterized by its programmability and advanced measurement functions. These power supplies support a wide range of output voltages and currents, allowing for flexible configurations that cater to different testing needs. The built-in measurement capabilities enable users to monitor the voltage, current, and power with high precision, which is essential for ensuring optimal performance in electronic applications.

The Agilent 669xA series stands out with its high-power outputs, making it suitable for demanding applications. These power supplies deliver high voltage and current levels, making them ideal for testing high-performance devices, such as power amplifiers and motor drives. Additionally, the 669xA series includes features such as overvoltage protection and complex output sequencing to enhance the safety and reliability of the testing process.

The Agilent 665xA and 664xA series focus on delivering high accuracy and excellent regulation. These models are particularly known for their low noise operation, which is critical for sensitive applications where precision is paramount. The integrated programming capabilities allow users to automate testing sequences, thus improving efficiency in research and development settings.

The 668xA series features advanced digital signal processing that enhances the precision and stability of the output. Users benefit from features like remote sensing and monitoring, allowing feedback adjustments that maintain output accuracy despite cable losses. Furthermore, the 668xA models can integrate seamlessly with various test environments thanks to their LAN, GPIB, and USB connectivity options.

Overall, the Agilent 667xA, 669xA, 665xA, 664xA, and 668xA power supplies provide a comprehensive range of solutions for diverse electronic testing needs. With their advanced features, superb measurement capabilities, and robust performance, these instruments empower engineers and researchers to conduct their work with confidence, precision, and efficiency.