DF/FF Series

  • Designed for Common XRD & XRF X-Ray Tubes
  • Compact Size, 5 1/4” (3U) High Chassis
  • Solid Encapsulation Ensures Maintenance-Free Operation
  • Auto Ramp of the HV Emission Current to Preset Values
2 Year Extended Warranty

3-4kW Industrial X-Ray Generators

Spellman’s DF/FF Series of X-ray Generators feature our new inverter design which incorporates IGBTs for power switching and provides new levels of reliability. In addi­tion, re-engineering of the DF/FF’s internal filament power supply eliminates audio noise at normal operating levels by operating at a higher frequency. The DF/FF’s utilize a sine wave current source, produced by phase shifting series resonant circuits at switching frequencies greater than 20kHz to generate high voltage dc. This technique eliminates undesirable electromagnetic radiation normally associated with switching and power control regulators. The high efficiency of these units allows for air cooling in a 5 1/4” (3U) high chassis. 

Typical applications:

  • X-ray Diffraction (XRD)
  • X-ray Fluorescence (XRF)


(Ref. 128001-001 REV. J)

Input Voltage:

220Vac ±10%, 50 or 60 Hz, single phase (three phase optional).

Output Voltage:

DF3: 0 to 60kV negative polarity.

FF3: 0 to 60kV positive polarity.

Other output voltages are available.

Output Current:

DF3: 0 to 80mA.

FF3: 0 to 100mA. Other output currents are available.

Maximum Output Power: 

3kW (4kW optional).

Output Voltage Regulation:

Load: 0.005% of rated output for full load change.

Line: 0.005% of rated output over specified input range.

Temperature Coefficient: 50 ppm/°C (20 ppm/°C optional).

Long Term Stability: 0.01%/8 hours.

Emission Current Regulation:

Load: 0.01% of rated output for a 10 to 60kV change.

Line: 0.005% of rated output over specified inputs.

Temperature Coefficient: 50 ppm/°C

Long Term Stability: 0.01%/8 hours.


0.03% rms <1kHz, 0.75% rms above 1kHz. 


Temperature Range:

Operating: 0°C to 40°C

Storage: -20°C to 85°C


10% to 90%, non-condensing.

Filament Voltage:

12Vac (dc filament optional).

Filament Current:

5A (up to 12A max available).


51/4”(3U) H x 19“ W x 22” D (13.3cm x 48.3cm x 55.9cm).


90 lbs (40kg).

Regulatory Approvals:

Compliant to 2004/108/EC, The EMC Directive and 2006/95/EC, The Low Voltage Directive.


Water Flow Switch:

A 24Vdc signal is available on the rear panel to turn on the cooling water to the X-ray tube. This signal can be enabled either when control power is on or when the high voltage is turned on. (Customer must specify).

Fail Safe Interlock:

A 24Vdc signal is available on the rear panel to energize an external X-ray on lamp. This signal is energized when the high voltage is turned on. High voltage will not enable if this circuit is open. (A 220Vac signal is optional).

Preheat and Ramp:

Automatic preheat and ramp control circuits are provided which ramp the kV and mA slowly to set levels. kV ramps in approximately 10 seconds while mA ramps in approximately 20 seconds.

Output Connector:

75kV, 3 conductor Federal Standard X-ray connector. -60kV is connected to terminal “C”. Terminals “S” and “L” are jumped together. The filament output is connected between terminals “C” and “S”. Other configurations are optional. (On the FF3, all output connections S, L, & C are connected together).

Remote Signal Connector:

Remote interface is available via a 50 pin mini D connector. Extensive remote programming and monitoring is provided. 


RS232 - RS232 Interface  
220FSI - 220Vac Fail Safe Interlock  
208-3P - 208Vac Three Phase Input


Pin Signal
1 +5Vdc (or connect to pin-11)
2 Control Power On
3 Intlk
4 X-Ray On
5 X-Ray Off
6 Spare
7 Spare
8 Reset
9 Rmt/Lcl
10 24V Switched
11 +5Vcch
12 X-ray On Status
13 Overvoltage
14 kV Min
15 Overpower
16 Filament Current Limit
17 mA Current Limit
18 LCL Status
19 Power Supply Fault
20 Gnd
21 Spare
22 (DF) Remote X-ray On
23 (DF) Remote X-ray On Ret
24 Spare
25 Gnd
26 kV Ref
27 kV Com
28 mA Ref
29 mA Com
30 Spare
31 Spare
32 Spare
33 Pwr. Limit (OL Ref)
34 Pwr. Limit Com (OL Com)
35 Filament Current Limit
36 Filament Current Limit Com
37 Spare
38 kV Monitor
39 mA Monitor
40 Spare
41 Spare
42 kV Ref Mon
43 mA Ref Mon
44 Spare
45 Spare
46 Filament Monitor
47 Mon Common
48 Spare
49 Gnd
50 Spare

Tables & Diagrams



DF/FF X-Ray Generator (Image 1)


DF/FF X-Ray Generator (Image 2)


DF/FF X-Ray Generator (Image 3)

Cost reduced version for OEM quantities available, contact Sales.

CE Marking

Note: All specifications are subject to change without notice. Please consult the PDF version of this datasheet for the most up-to-date revision.