FAST RESPONSE
FOUR-QUADRANT BIPOLAR POWER AMPLIFIER
- Voltage rRnge:
±20 V to ±60 V - Current:
±2.5 A to ±100 A - Power:
150 W to 2000 W - Fast Response:
DC to 200 kHz
Fast response four-quadrant bipolar amplifier
The DOS series is a four-quadrant bipolar amplifier featuring a high-speed response of DC to 200 kHz (CV mode). When combined with a function generator, it can output various waveforms, including sinusoidal, triangular, sawtooth, and rectangular waves. Since the DOS series amplifies external signals accurately, it is ideal for diverse simulation tests. It supports both sourcing and sinking operations in Constant Voltage (CV) and Constant Current (CC) modes. Despite its versatility and ultra-high-speed response, the unit remains compact. With high-visibility meters and user-friendly operation, the DOS series is an excellent choice for applications ranging from R&D laboratories to production lines.
Note: This product is not designed for charge and discharge of battery.
For battery charging and discharging applications, please refer to the Battery Cycle Tester product page.
Features
- Fast response
-
Suitable for transient response test because of its ultra-high-speed response DC to 200 kHz and high power, maximum 2000 W.
- Four-quadrant action
-
DOS series can be used both as a high-speed response DC power supply and as a DC electronic load.
- DC bias setting (DC offset voltage/current setting)
-
The output DC bias can be adjusted with the 10-turn "BIAS" potentiometer on the front panel. When used as a DC power supply, it functions as an output setting volume. When an AC waveform is output, the DC (bias) voltage/current is superimposed on it.
- Constant Voltage (CV)/Constant Current (CC)
-
A single switch selects between CV and CC modes.
- Compact & Lightweight
-
For maximum compactness and lightweight, the DOS series has been improved for small footprint and handiness.
- DC output meter equipped
-
3-digit digital meter displays the DC value of the output voltage and current. (The option of rms indication is available.)
- Complete protective functions
-
Protective functions against overvoltage/overcurrent and against output short-circuit are completely provided.
- Master/Slave
-
Master-slave control (option) for more power requirement. Both the Master unit and Slave unit are usable as the individual amplifiers. (Frequency response will vary in case of master-slave operation, please ask sales staff.)
Applications
- Inductive load such as coil and transformer
- Various motor tests
- Evaluation test for solar panel-related devices
- Ripple test of capacitors
- Voltage regulation tests for in-vehicle electrical component
- For surface treatment
Models
* Models with voltage, current, or frequencies not listed here are also available. Please contact the nearest sales office.
| Model | Maximum output | ||
|---|---|---|---|
| Voltage | Current | Power | |
| DOS20-7.5 | ±20 V | ±7.5 A | 150 W |
| DOS20-15 | ±20 V | ±15 A | 300 W |
| DOS20-30 | ±20 V | ±30 A | 600 W |
| DOS20-60 | ±20 V | ±60 A | 1200 W |
| DOS20-100 | ±20 V | ±100 A | 2000 W |
| DOS25-6 | ±25 V | ±6 A | 150 W |
| DOS25-12 | ±25 V | ±12 A | 300 W |
| DOS25-24 | ±25 V | ±24 A | 600 W |
| DOS25-48 | ±25 V | ±48 A | 1200 W |
| DOS25-80 | ±25 V | ±80 A | 2000 W |
| DOS45-3.3 | ±45 V | ±3.3 A | 150 W |
| DOS45-6.6 | ±45 V | ±6.6 A | 300 W |
| DOS45-13.3 | ±45 V | ±13.3 A | 600 W |
| DOS45-16 | ±45 V | ±16 A | 720 W |
| DOS45-26.7 | ±45 V | ±26.7 A | 1200 W |
| DOS45-44.4 | ±45 V | ±44.4 A | 2000 W |
| DOS60-2.5 | ±60 V | ±2.5 A | 150 W |
| DOS60-5 | ±60 V | ±5 A | 300 W |
| DOS60-10 | ±60 V | ±10 A | 600 W |
| DOS60-20 | ±60 V | ±20 A | 1200 W |
| DOS60-33.3 | ±60 V | ±33.3 A | 2000 W |
Functions
Protective Functions
Overvoltage Protection (OVP)
DOS series is equipped with overvoltage protection, which protects load by limiting voltage up to approx. 110% of the rated output voltage even at abnormal conditions.
* It is possible to set variable 0% to approx 110% output voltage range with -LVc option.
Overcurrent Protection (OCP)
DOS series is also equipped with overcurrent protection, which protects power supplies and load by limiting current up to approx 110% of the rated output current.
* It is possible to set variable 0% to approx 110% output voltage range with -LCc option.
High-speed Overcurrent Protection
The DOS series is provided with 2 types of overcurrent protections, high-speed overcurrent protection to limit the pulse current, and standard overcurrent protection to limit the static current.
The standard overcurrent protection limits the static current, responding at around 1 msec.
Additional high-speed overcurrent protection can limit the pulse current of square waveforms or from a capacitive load at approximately 2 times the rated current.
Output Range
DOS series is a bipolar power supply that can perform four-quadrant operation. They can supply (source) and absorb (sink) current in the field of the drawing on the right.
Characteristic of Amplifier
Rise Time
(Stepping time): The response time is sometimes described by the rise time (as shown in the drawing on the right).
The rise time of an amplifier at a response speed of (= frequency bandwidth) Fc (Hz) is generally acquired by "tr ≒ 0.35/fc."
Fall time tf is the same as tr.
Frequency bandwidth: at 200 kHz or lower, tr = tf = around 1.8 μs, at 100 kHz or lower, tr = tf = around 3.5 μs
Response Speed
When accurate output waveforms are required, select an amplifier with a frequency bandwidth higher enough than the operating frequency.
In the case of using sine waves, 3 to 5 times more frequency bandwidth is required, and around 10 times more in the case of square waves in general.
Inadequate bandwidth causes not only a decrease in the output amplitude but much difference between the input and output phases. Therefore, operating the product while monitoring the actual output waveforms is recommended.
Inductive Load
Some inductance of inductive load may cause resonance in CC mode.
In such cases, connect a C-R series circuit between output terminals to prevent resonance.
Capacitive Load
Resonance may occur if the capacitive load exceeds 100 pF (including stray capacitance of the output wire). In such cases, insert a high-voltage resistor of 100 Ω (at 0.1 μF) to 1000 Ω (at 1000 pF) in series with the output. Please note that the frequency bandwidth is limited when driving a capacitive load, as shown in the formula on the right.
Additionally, using the amplifier for corona discharge applications may cause current exceeding the rating to flow, potentially damaging the unit. In this case, as well as when driving capacitive loads, please install an output limiting resistor to restrict the current.
* Avoid continuous input of high-frequency signals that exceed the amplifier's output frequency capabilities. Excessive internal loss may cause the amplifier to fail.
Specifications
- Input voltage
-
100 to 120 Vac, 50/60 Hz, Single-phase (150/300 W models)
200 to 240 Vac, 50/60 Hz, Single-phase (600/1200/2000 W models)
200 to 240 Vac, 50/60 Hz, Single-phase (150/300 W models option) - Output control
-
[External control signal] Vcon-in, Input voltage -10 to +10 V
[Front panel] DC bias: 10-turn potentiometer with -100% to +100% setting
Options
- -LCc
-
Output Current Limit
The limit can be adjusted from 0% to approx. 110% using the front panel dial.
- -LF
-
Floating ground (withstand voltage 200 Vdc)
FAQ: What is floating ground?
- -LMsm: Master machine for master-slave control
-LMss: Slave machine for master-slave control -
By connecting a master machine and a slave machine with dedicated control lines, the master machine can control all slave machines at once. A parallel connection can increase the current that is insufficient for a single operation. Up to three units in total can be connected: one master unit and up to two slave units.
Note: Precautions for using the master-slave operation- Only master-slave connection is available for the same model.
- In parallel operation, the frequency range is narrower.
- It can also operate on a single.
- Factory adjustment is required when changing the master-slave combination.
- -LN
-
Automatic Output Recovery
This option retains the output state when recovering from an input power interruption, such as toggling the AC power switch or a power failure. The user does not need to reset the protection status by manually cycling the OUTPUT switch.
Caution: If power is restored while the OUTPUT switch is set to ON, the unit will resume output immediately.
- -LPr
-
rms display
- -LVc
-
Output voltage limit
Variable from 0 to approx 110% with the dial on the front panel
- -L(220V)
-
200 Vac to 240 Vac ±10% single-phase, 50 Hz/60 Hz input
(150 W and 300 W models only)
How to Order
When placing an order, please add the option code(s) after the model name.
If adding two or more options, omit the “-L” from the second and subsequent option codes, and list them in alphabetical order.
<Example> DOS25-12-LCcDFMsmNPrSVc(220V)
Accessories
- Function Generator
-
Dimensions
Download
If you are unable to download a file
Please try the following solution.
- Please press Ctrl+F5 to clear the cache of your web browser and try again.
- Please restart your web browser and log in again to try again.
- Please change your web browser to another browser and try again.
- Restart the computer and try again.
- Please try again on a different computer.
-
DOS series Datasheet
Date: 2025-07-03 rev.16
PDF (2,263 KB)
-
Bipolar Power Supplies Selection Guide Via External Signal input
Date: 2025-06-30 rev 08
PDF (4,774 KB)
-
Bipolar Power Supplies/Amplifiers Selection Guide
Date: 2023-10-17 rev.03
PDF (6,310 KB)
-
DOS series Instruction Manual
Date: 2022-7-25 rev 0.7
PDF (1,219 KB)
-
DOS series (1200W, 2000W) 3D MODELS (STEP, IGES)
Date: 2025-10-27
ZIP (11,104 KB)
-
DOS series (1200W, 2000W) (-LMsm/-LMss option model) 3D MODELS (STEP, IGES)
Date: 2025-10-27
ZIP (11,341 KB)
-
DOS series (1200W, 2000W) Outline Drawing (DXF, PDF)
Date: 2025-10-29
ZIP (555 KB)
Login Required
-
DOS series Datasheet
Date: 2025-07-03 rev.16
PDF (2,263 KB)
-
Bipolar Power Supplies Selection Guide Via External Signal input
Date: 2025-06-30 rev 08
PDF (4,774 KB)
-
Bipolar Power Supplies/Amplifiers Selection Guide
Date: 2023-10-17 rev.03
PDF (6,310 KB)
-
DOS series Instruction Manual
Date: 2022-7-25 rev 0.7
PDF (1,219 KB)
-
DOS series (1200W, 2000W) 3D MODELS (STEP, IGES)
Date: 2025-10-27
ZIP (11,104 KB)
-
DOS series (1200W, 2000W) (-LMsm/-LMss option model) 3D MODELS (STEP, IGES)
Date: 2025-10-27
ZIP (11,341 KB)
-
DOS series (1200W, 2000W) Outline Drawing (DXF, PDF)
Date: 2025-10-29
ZIP (555 KB)
On this website, we provide only the latest versions of information and instruction manuals for our products. Therefore, the newest versions of manuals on the website may differ from those that came with products you purchased in the past.
