DC Bias Units
3265B/5A 3265B/10A 3265B/20A
3265B/25A 3265BQ/25A

  • Enhances usability of Wayne Kerr Analyzers
    • 3255BL Inductance Analyzer
    • 3255B Inductance Analyzer
    • 3255BQ Inductance Analyzer
    • 3260B Precision Magnetics Analyzer
  • DC Bias Unit can deliver between 25 mA and
    Up to 125 A DC bias current in steps of 25 mA
  • DC Bias Fixture model 1009 allows accurate and safe testing of SMD inductors
  • Adds additional functionality

Component tests up to 125 A DC bias current

To evaluate components at high currents the 3265B/25A DC Bias Units may be used with either the Wayne Kerr 3255B Inductance Analyzer or the 3260B Precision Magnetics Analyzer. Bias current may be set from 25mA to 25A in steps of 25mA. These units may not be used with a 3255BL.

Additional DC Bias Units can be added in parallel such that with five units connected in parallel it is possible to set bias currents up to a maximum of 125 A DC. For extended frequency, up to 3 MHz, 50A is available when two 3265BQs are used.

5A, 10A and 20A models are available which may be connected in parallel to give up to five times the maximum rated DC bias current. 

The instruments have a number of safety and protection features including a safety interlock system to protect the user against back EMFs. It is also fully protected against over temperature, excess voltage drop and sense lead failure.

3265B/25A DC Bias Unit can deliver up to 25 A of DC bias current in steps of 25mA

SMD inductor tests up to 50 A

With the addition of the 1009 DC Bias Fixture DC bias currents up to 50 A can be applied to an SMD inductor during component test in order to evaluate the devices thoroughly at the operational bias currents.

The fixture operates with either one or two 3265B Wayne Kerr DC bias units and a 3260B Precision Magnetics Analyzer. The optional 1009 50A lead set, 5-328-2005, will be required if two 3265B/25As are used.

Four rear panel mounted BNC connectors and two captive high current cables ensure simplicity and ease of use with the 3265B.

Interchangeable component test carriers ensure that the 1009 DC Bias Fixture may be used with a wide variety of devices. If a device package is not supported by one of the standard carriers then a custom carrier design service is available.

1009 DC Bias Fixture enables currents up to 50 A to be applied to an SMD inductor

Stable component fixturing ensures high accuracy and repeatable measurements. Enclosed fixtures, with safety interlocks, minimises risk to operators.

Technical Specifications

Compliance voltages
Maximum compliance voltage (<12 kHz) 11 V DC at 0.25 V AC drive level.
10 V compliance at 1 V AC drive level. For f>12 kHz deduct 0.5 V.

Must be used in conjunction with either a 3260B or 3255B
Permits measurement analysis of wound components with levels of DC bias current higher than the standard 1A
Variable measured
In impedance mode: L, Z, R, Q, D.

Not applicable to Rdc, or transformer measurements
Measured frequency range
3255BL 20 Hz to 200 kHz (not compatible with 3265B/25A and 3265BQ/25A)
3255B 20 Hz to 500 kHz
3255BQ 20 Hz to 1 MHz
3260B 20 Hz to 3 MHz (3265BQ/25A)
Basic accuracy

Varies with measurement speed, frequency and options chosen.
Measurement terminals
2-terminals measurement via M8 studs.
4-terminal measurement via Kelvin leads and M8 studs.
Measurement terminals internally protected by 1.6A fuses against normal inductor back-EMF or accidental disconnection of inductor.
Front panel fuses easily replaced.
Control connections
I2C bus link controls application of DC current and monitors status of analyzer. Status data includes excessive voltage drop and over temperature
Optional facilities
3265B bias units may be paralleled, maximum of five units.
Bias safety interlock socket on rear panel of analyzer provides door lock and closed control lines
Temperature range
Storage: -40C to 70C.
Operating: 0C to 40C (20 A max)
Full accuracy: 15C to 30C (25 A max)
Power supply
Universal 90 to 255 V AC, 47 to 63 Hz
Input current 9 A rms max.
Power factor >0.9

Unit powers up automatically when connected to a powered analyzer. Isolating switch provided
Height 190 mm (7 1/2″)
Width 440 mm (17 3/8″)
Depth 520 mm (20 1/2″)
Weight 15 kg (33 lb)
Fan cooled. Intake front, exhaust rear. Fan filter accessible on front panel. Over temperature trip provided

Order codes and options

5A DC bias unit 3265B/5A (1 MHz) 1J3265B/5A
10A DC bias unit 3265B/10A (1 MHz) 1J3265B/10A
20A DC bias unit 3265B/20A (1 MHz) 1J3265B/20A
25A DC bias unit 3265B/25A (1 MHz)
Not compatible with 3255BL
25A DC bias unit 3265BQ/25A (3 MHz)
Not compatible with 3255BL
Both units supplied with user manual, power cable, spare fuses, 4 x BNC to BNC links, daisy chain link, rack mounting ears (unit needs rear support) and bus bars.
Kelvin clips leads (fine jaws) 1EVA40100
Kelvin clips leads (large jaws) 1EVA40180
Power transfer bus bars (Two each per unit in parallel) 4-324-6009
Filter pad (washable) HMDEC10
1009 DC Bias Fixture 1J1009
1009 50A Lead Set 5-328-2005