The HP/Agilent 42842B Bias Current Test Fixture is a specialized accessory for DC bias current measurements on components using impedance analyzers and the HP 42841A Bias Current Source. It enables characterization of inductors, capacitors, and transformers under DC bias conditions, essential for understanding real-world performance. The fixture accommodates devices up to 80 mm (W) × 80 mm (H) × 80 mm (D) and supports DC bias currents up to 40 A with measurement accuracy of 2% below 1 kHz and 1% at 1 kHz and above.
Technical Specifications
• Maximum DC Bias Current: Up to 40 A
• DUT Connection: 2-terminal
• Frequency Range: Up to 2 MHz (general); up to 1 MHz with HP 4284A; up to 30 MHz with HP 4285A and 42842C; up to 110 MHz with 4-terminal pair setup
• Measurement Accuracy: 2% (< 1 kHz); 1% (≥ 1 kHz)
• Residual DCR: Approximately 3 × 10⁻³ Ω
• Maximum DUT Size: 80 mm (W) × 80 mm (H) × 80 mm (D)
• Fixture Dimensions: 237 mm (W) × 173 mm (H) × 235 mm (D)
• Weight: Approximately 3000 g
– Key Features
• BNC(f) bias voltage output connector
• Voltage monitor terminal for direct DVM connection; 10 MΩ input impedance minimum recommended due to 10 kΩ monitor output resistance
• Clear plastic cover for safe observation
• Back-EMF reduction: opening cover reduces back-EMF voltage to below 40 V within 0.1 second
• Heat-sensitive switch for overheating protection
• Automatic bias current cut-off at abnormally high temperatures (200 °C at DUT; 70 °C at measuring terminal)
• Automatic component discharge when protective cover opens
• Direct connection to HP 42841A bias current source terminals
– Typical Applications
Component impedance characterization under DC bias; inductor, capacitor, and transformer performance evaluation in biased conditions.
– Compatibility & Integration
Works with impedance analyzers including HP 4284A (up to 1 MHz), HP 4285A (up to 30 MHz with 42842C), and general analyzers to 2 MHz. Interfaces directly with HP 42841A Bias Current Source.
