• DOEF series
  • DOEF series

DOEF series

Sequence Function Installed High Speed Response Bipolar Power Supply

  • Max Voltage: ±20V to ±60V
  • Max Current: ±10A to ±20A
  • Max Power: 1200W
  • High speed response of DC to 200 kHz

High speed response of DC to 200 kHz

DOEF series are four-quadrant power supplies possible to source and sink current. They can be applied widely according to the usage from transient response test to various evaluation tests as they realize high speed response of DC to 200 kHz (at constant voltage mode) and can generate basic waves such as sine wave, rectangular wave, and programmed waves by embedded function generator.

And, as they provide also sequence function as standard, you can program output patterns in detail. Moreover, as their generation of wave and setting sequence can be made all with the simplified operation on the front panel, you can make full use of various functions easily.


  • High speed of DC to 200 kHz is realized.
  • Four-quadrant behavior is able to source and sink current.
  • It is possible to generate non-distortional wave such as sine wave, rectangular wave.
  • It is possible to set and operate highly accurate sequence of 1024 steps.
  • Individual setting of DC and AC is possible. Superior usability is realized together with the simplified operability.
  • 2 modes operation of CV (constant voltage) and CV (constant current) are applicable.
  • It is possible to connect maximum 3 power supplies in parallel (synchronized trigger) by coinciding accuracy of frequency (synchronized clock) in synchronized operation.
  • External digital control is available (USB).
  • It is possible to output voltage/current in 16 bits and optional waves of resolution of 1024 in one cycle by using dedicated software.
Four-quadrant operation
  • Vo max: rated output voltage
  • Io max: rated output current
This image is graph.legend
DC and AC output control external control DC and AC output control external control

Main applications

  • Voltage fluctuation tests for automotive electrical components such as car navigation system
  • Voltage fluctuation tests for automotive battery (Simulation of waveform of cranking)
  • As Constant current power supply for electromagnet
  • Tests of various DC motors
  • The test which apply ripple current to a capacitor
  • Examination to evaluate the characteristic of the magnetic material
  • As high speed power supply for pulse plating
  • For measuring the loss of a transformer or a reactor
  • The test which apply transient current to a breaker or relay
  • To drive piezoelectric elements
  • Evaluation of power conditioners
This product is not designed for charge and discharge of battery. Please contact nearby sales if unit is used for charge and discharge application.


We can manufacture other specifled voltage, current and frequency band written as followings.

Model Output Frequency Bandwidth [kHz (-3 dB)]
Maximum Voltage [V] Maximum Current [A] Maximum Power [W] At CV mode At CC mode
DOEF20-20 ±20 ±20 400 DC to 200 DC to 100
DOEF40-10 ±40 ±10 400
DOEF60-10 ±60 ±10 600
DOEF60-20 ±60 ±20 1200


Basic Wave Generation Function

DOEF is equipped with a built in function generator that produces basic waves such as sine, rectangular and triangle waves.
Frequency range can be set between 0.01 Hz and 200 kHz. Easy adjustments/edition of amplitude, initial phase (for sinewave), phase shift (for sine wave), and duty ratio (for rectangular/triange wave) are possible. DOEF has special feature of "soft start" and "soft stop" which enable to program initial rise and fall characteristics of the output.

Starting phase Starting phase
Soft start Soft start

AC Volt/Current sweep, frequency sweep

Soft stop Soft stop

DC Volt/Current ramp


Power activation test, various start-up tests of motor, fluctuation test of wave shape, etc.

Sequence Function

DOEF is equipped with sequence function that can program parameters such as step length, step amplitude ramp, DC voltage and current ramping, AC voltage and current ramping, frequency sweep, AC superposition, step jump, and jump times. These useful functions help to program the desired waves in very flexible manner,resulting to support efficient laboratory and research works.

Very complex sequence can be created easily with the easily understandable display.
Sequence function
Sequence function
  • Step setting length 0.1 ms to 1000 h (resolution of 0.1 ms)
  • Maximum 1,024 steps per program.
  • Maximum 64 programs can be stored in memory for each CC/CV operation
  • Program repeat can be set by "endless repeat" or "1 to 10,000 times"
  • Multiple programs can be converted to activate
Image of Programs
Image of Programs

Sequence functions help to create complicated waves like below to be simply and easily edited.

Pulse current variation Pulse current variation
Ripple current superpose Ripple current superpose
AC voltage variation AC voltage variation
DC voltage cutoff DC voltage cutoff

Measurement Function

DOEF is equipped with measurement function that can measure DC value, AC RMS value, and Max/Min value, likewise, it is possible to automatically measure wide range bandwidth from DC to 120 kHz. There are 4 parameters which are simultaneously displayable, each of these parameters are individually programmable. As this measurement is standard feature, no option needs to be purchased. This sophisticated feature will reduce time for editing output waves and bring up work fficiency.

Measurement Function 1
Measurement Function 2

Synchronized Operation (-Lso option)

The following DOEF operations are available for up to three units.

Synchronous Trigger
Through a single operation of the master unit, it is possible to match the output timing of ON/OFF in one or two slave units. In turning the output on, the output starting gap between the master and the slave is less than 0.5 µs
* When this option is selected, we provide two meters of dedicated cables for synchronized trigger function used for two or three devices.
Synchronous Clock
By providing the clock input of 10 MHz, the individual difference between the oscillators installed on each unit is removed (In the case of this, there are a few ppm up to several tens ppm in general). What is more, frequency accuracy and sequence-step time are completely unified through the operation.
Moreover, the product is also available for setting the phase shift difference for sine wave toward each unit.
(* Please prepare the coaxial cable on both ends of BNC connectors which is not included but required for synchronous clock
* When the slave unit is required to synchronize in accordance with the waveform set by the master unit, -LMs option must be taken (in master/slave control). Meanwhile, selecting -LSo option and -LMs option simultaneously is not allowed.
Other functions:
Protection Function (Cut-off, Individually Settable Limiter Protection), Key Lock Function, Switching CV/CC and Memory function (up to 99) are installed as standard.



  1. Display: Display various settings and measurements.
  2. OUTPUT switch: ON/OFF for output
  3. Rotary encoder: Change value
  4. POWER switch: ON/OFF for main power
  5. CANCEL switch: Cancel settings
  6. ENTER switch: To confirm and key in
  7. CV/CC switch: Switch over CV/CC mode
  8. DC/ACDC switch: Switch DC/AC+DC mode
  9. Setting/Storage switch: Make to setting change menu, store memory
  10. Protection switch: To switch protection setting menu
  11. Shift down switch: Shift down each setting items
  12. Shift up switch: Shift up each setting items
  13. Sequence switch:Use for switchover of sequence screen or interrupt or restart of sequence operation
  14. Shifting left/Memory switch: Shift digits of settings to left and also use switchover memory screens.
  15. Shifting right/LOCK switch: Shift digits of settings to right and also use key lock function


For details, download the datasheet below.


-LGob: Optical Interface Board *

Insulation control is made with optical communication. As perfect insulation is made by optical fiber it is able to forestall miss operation by transient phenomenon caused by surge, dielectric thunder or foreign noise, etc.
When this option is selected, 2 m length of optical cable is supplied.

Remote switch ON/OFF, variable voltage/current (AC and DC), switching constant voltage/constant current, variable frequency, setting of waveform (sine wave, rectangular wave, triangle wave), setting of phase (sine wave), setting of duty (rectangular wave, triangle wave).

(Adapter is required otherwise. Please inquire our sales staff.)

-LCk: CC-Link Interface Board*

It enables digital remote control via network of CC-Link. We may accept optimization for specific industrial network such as Device NET. Please inquire our sales staff for details.

-LMsm, -LMss: Master/slave Control (parallel operation)

Maximum 3 units including master unit are hooked. "-LMsm" for the master unit and "-LMss" for slave units. Please order required number of units. Every master unit and slave units are exclusive use, but operating individually is also available. When change the combination of master/slave, they should be readjusted in our shop.
In addition, either communication option (-LGob, -LCk or -LUs1) is necessary for a master unit when the power supplies in master slave connection are controlled by digital communication. Slave units also require these options for their individual operation. (-LGob, -LCk or -LUs1)
(It is impossible for this to select -LSo option simultaneously.)

-LSo: Synchronized Operation

Maximum 3 units can be operated in parallel.
Accuracy of output frequency and sequence time coincide by synchronizing with multi units and it is possible to output the same wave all together.
Only in case of sine wave, it can output with phase difference given.

-LVs: Shifting Function for Output Voltage

Optional 120 Vp-p within the range of -115V to +115 V (only for DOEF60-10 and 60-20).

-LUs1 *: USB interface board

Enable digital control with USB. One power supply can be connected per one USB port which computer equipped.
In case USB port which computer equipped is not enough, please use USB hub. However, depending on USB hub, it may not work correctly.

OS: Microsoft Windows XP/Vista/7/8/10 (Both 32-bit version and 64-bit version are available.)

Microsoft Windows is a registered trademark of Microsoft Corporation in the United States and other countries

How to Order

To order, please add the above option to the model number.
(Alphabetical order)


For details, download the datasheet below.

Tech Notes

Capacitive Load

When a capacitive load is more than 100 pF (including a stray capacitance of output wire), the resonance in the output may occur. In that case, install 100-ohm (@0.1 μF) to 1000-ohm (@1000 pF) of high voltage resistance in the output in series. Please note that the frequency band will be limited as the formula written in the right figure when an amplifier is used with a capacitive load.
In addition, when an amplifier is used for the use such as a corona discharge, the current which is higher than rating will flow and it will affect the amplifier badly. In this case, as well as the time to use an amplifier with a capacitive load, please install the output resistance and limit the current.

* Please avoid continuous inputting of high frequency signal which reduces output frequency of an amplifier. An amplifier will be broken because of increase of internal loss.

This image explains frequency band when a capacitive load is connected.

Read more


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Bipolar power supplies/High voltage Amplifiers