Overview

The 6565 HF DC Bias Unit is intended to be used with a Wayne Kerr 6500 analyzer, either the 6500B Precision Impedance Analyzer or the 6500P HF LCR Meter. Its function is to provide a source of DC bias current through the Device Under Test (DUT) while the analyzer is making AC measurements. Each 6565 unit can provide up to 10 A of DC current, and up to six 6565 units can be connected in parallel to supply a maximum 60 A. A digital ammeter on the front panel allows the user to see the dc bias current value and an indicator LED shows when the bias current is enabled.

High current 50Ω coaxial cable is used to carry the DC bias current from the 6565 unit to the fixture. The measurement signal from the 6500 analyzer front panel is connected to the fixture using a dedicated cable, a control cable connects the rear panels of the 6500 and 6565, and a safety interlock cable is connected from the fixture to the rear panel of the 6565.

There are 3 models in the 6565 series. The models are defined by their frequency range as follows:

           6565-05             20 Hz to 5 MHz

           6565-30             20 Hz to 30 MHz

           6565-120           20 Hz to 120 MHz

 

Any 6500 analyzer can be used with any 6565 unit. The maximum measurement frequency of the system will be determined by the instrument with the lower maximum frequency. For example, a 120 MHz 65120P used with a 5 MHz 6565-05 will have a maximum measurement frequency of 5 MHz

The 6500 analyzer controls the 6565 unit. The DC bias current is set as part of the 6500's measurement setup and the 6565's status and warning messages are shown on the 6500's display.

A common wound component measurement with the 6500B/6565 system is to measure the value of inductance as the DC Bias Current through the DUT is swept from 0A to the DUT's rated maximum current.

Another common technique is to use the Reference Trace function on the 6500B Precision Component Analyzer. This allows frequencies sweeps performed at different DC bias current levels to be instantly displayed and compared on the 6500B's display, as shown in the example screenshot below.

Frequency sweeps for Impedance and Phase Angle for 0 A and 10 A DC Bias Current

Key Features

• No comparable system is currently available from other manufacturers
• Allows measurements up to 120 MHz to be made with 40 A DC Bias Current flowing through the Device Under Test
• Measurements up to 15 MHz can be made with 60A DC Bias Current
• 6500B analyzer allows measurements to be made while sweeping DC Bias Current in value
• Frequency swept measurements with different DC Bias Currents can be compared using the 6500B Reference Trace facility
• Wayne Kerr fixtures provide a safety interlock circuit and other protection circuits to protect both the operator and the equipment under fault conditions