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Q1 gw_product_detail_bar.png gw_product_detail_bar.png Power Supplies and Load Rack Mount Kit (2)

GRA-413-E for PEL-3221/3211H

GRA-423 for APS-7050/7100/7050E/7100E series

GRA-418-J (JIS) for PSB-1000 series

GRA-418-E (EIA) for PSB-1000 series

GRA-424 for PSB-2000 series

GRA-429 for APS-7200 series

GRA-431-J (JIS) for PFR series

GRA-414-E (EIA) for PEL-3021/3021H/3041/3041H/3111/3111H/3031E/3032E

GRA-424 for PSB-2000 series

GRA-419-J (JIS) for PCS-1000i

GRA-419-E (EIA) for PCS-1000

GRA-428 for PSP series

GRA-430 for APS-7300 series

GRA-431-E (EIA) for PFR series 


Q2 gw_product_detail_bar.png gw_product_detail_bar.png Power Supplies and Load Rack Mount Kit (1)

GRA-401 for PPE-3323/PPT-1830/PPT-3615

PEL-002 for PEL-2000 series

GRA-403 for PSH-series

GRA-407 for PSM-series and PST series

GRA-413-J (JIS) for PEL-3211/3211H

GRA-408 for PSS-2002/3203

GRA-409 for APS-1102A

GRA-410-J (JIS) for PSW-series

GRA-410-E (EIA) for PSW-series

GRA-414-J for PEL-3021/3021H/3041/3041H/3111/3111H/3031E/3032E


Q3 gw_product_detail_bar.png gw_product_detail_bar.png What are the requirements for verifying the electronic load of the LED driver?


The electronic load verifying the LED driver not only has the functions of a general electronic load (CC, CR, CV, CP), but also must be able to simulate the load characteristics of the LED, set the forward bias (Vd) and the on-resistance ( Rd), etc. In addition, the built-in dimming control signal output is convenient for the PWM dimming test of the LED driver.


The dedicated electronic loads that GW Instek supports for LED driver testing are as follows:


  • Must be installed on  3302G mainframe [single channel], 3305G [two channels] or 3300G [four channels], and the mainframe has 150 sets of store/recall memory
  • 341G LED DC Electronic Load Simulator 300V, 24A, 300W
  • 3342G LED DC Electronic Load Simulator 500V, 12A, 300W
  • 3343G LED DC Electronic Load Simulator 500V, 24A, 300W
  • 3345G LED DC Electronic Load Simulator 120V, 4A, 150W
  • 3346G LED DC Electronic Load Simulator 120V, 12A, 300W
  • 33401G LED DC Electronic Load Simulator 500V, 6A, 150W*2
  • 33402G LED DC Electronic Load Simulator 120V, 2A, 75Wx2
  • 33403G LED DC Electronic Load Simulator 120V, 6A, 150Wx2
  • The power input dimming frequency of 3345G & 33402G can reach 25KHz, which is the fastest and widest bandwidth electronic load in the market
  • The dimming control output of 3345G & 33402G is DC~10KHz (other models are DC~1kHz)
Q4 gw_product_detail_bar.png gw_product_detail_bar.png How do you perform data logging from the measurement function of the ASR series AC/DC power supply?


The measurement function of the ASR series AC/DC power supply can be performed through the free software to perform data logging (Data Logger)


The software diagram is as follows

ASR data logger

Figure 1 Data logging of ASR measurement parameters

ASR Data Logger 1

Figure 2 Harmonic data logging


For free software, please click the link below, file download option, registered members can download for free after login



Q5 gw_product_detail_bar.png gw_product_detail_bar.png What conditions will the power supply activate over-voltage protection (OVP)?

The power supply over-voltage protection (OVP) is designed as a DUT protection mechanism to avoid supplying excessive voltage to the device under test (DUT) or circuit under test (DUC).


Three possible overvoltage (OVP) scenarios are provided below.


Scenario 1: Users forget that the overvoltage protection was set for the last project, and the voltage of this test project is higher than the overvoltage protection setting value.


For example: the OVP of the last project was set to 12.5V, the required voltage of this project is 15V, and the set output voltage is higher than the 12.5V of the overvoltage protection, so the power supply starts the protection mechanism to stop the output.


Scenario 2: After connecting the remote compensation, the output of the power supply is higher than the overvoltage protection setting value due to compensation


For example: the working voltage of the circuit is 12V, and the overvoltage protection is set to 12.5V. Due to the excessive loss from wiring, a voltage drop of 0.6V is caused on the wiring, resulting in only 11.4V voltage of the DUT. The power supply starts to compensate, and the compensation reaches 12.5V, the DUT is 11.9V, and the overvoltage setting value of 12.5V is exceeded after compensation, so the power supply starts the protection mechanism to stop the output.


Scenario 3: Due to the inductance of the test lead, at the moment of the power supply switching or the moment of the programmable voltage change, the stray components on the lead cause LC resonance, and the transient voltage during the voltage change exceeds the OVP protection voltage setting value.



Q6 gw_product_detail_bar.png gw_product_detail_bar.png Why is the computer still unable to detect the instrument after installing the Win7 driver of APS-1102A?

In addition to installing the driver for the APS-1102A, your computer must also have NI-VISA installed.

Q7 gw_product_detail_bar.png gw_product_detail_bar.png How do I improve the test capacity of programmable power supply?

During the production line test, the programmable DC power supply provides voltage, current, and test time. These three programmable variables enable the automation of complex production line test procedures. However, if you want to further improve the test capacity after automation, you must understand the design and special features of programmable power supply.


First, we need to understand the output characteristics and load effects of the DC power supply.


In order to provide a stable DC output, the DC power supply will have a capacitor at the output to perform the filtering work, and the capacitor does not allow the voltage to change instantaneously, so when you want to change the voltage output, the DC output filter capacitor will make this change a dilemma of application. The smaller the output ripple, the slower the response speed of the voltage change.


The output voltage should become larger: fast when no load, slow when loaded. Life scenario: A car full of passengers and an empty car climb a hill. Under the same throttle condition, the empty car climbs quickly, and the fully loaded car climbs slowly.


The output voltage should be smaller: slow when no load, fast when loaded. Life scenario: a car full of passengers and an empty car go downhill. When the accelerator is not stepped on, the empty car goes downhill slowly, and the full load goes downhill fast. When the power supply provides the function of the bleeder resistor, the voltage reduction time can be increased through the bleeder resistor.


If you need the power supply to perform rapid voltage changes (100u sec level), you can use the DC mode of the AC power supply, such as GW Instek ASR-2000 series, ASR-3000 series AC/DC dual-purpose power supplies.


If a rapid change in current is required, an electronic load can be used to extract the load, forcing the power supply to provide fast current.


In addition to the above issues, the setting time of the hardware and the computer control interface (GPIB, RS-232, USB, LAN) adopted will affect the time of the programmable voltage change.


Application Keywords: Rise Time, Fall Time



Q8 gw_product_detail_bar.png gw_product_detail_bar.png What are the steps to check if the power supply has no output?

Step 1: Check whether the AC input of the power supply is normal? Is it because the power strip controlled by the switch is forgot to turn on or was turned off by a colleague without being noticed. Check whether the display on the power supply has a display, if not, please check whether the fuse of the power supply is blown.

Step 2: After confirming that the power input is normal, set the output voltage and current of the power supply, both of which cannot be 0 (especially note that the current cannot be 0). If it is found that the setting value cannot be displayed, some GW Instek models provide a keyboard lock function to ensure that the setting value is not misused during the test. Please confirm whether the model you are using has this function. If so, please confirm that the Key Lock indicator is off, if the Key Lock light is on, please unlock it first. If the power supply still cannot be set, please confirm whether the power supply is connected to the computer. If the computer is connected, the remote control mode will cancel the Local operation.

Step 3: If the power supply has an output control switch, please press on. Power supply with an output control switch often has a light signal indicating that the output is turned on.

Step 4: If the output control switch is turned on and the light is not on (the light may be faulty, but the power supply still has output), please use the voltage range of a multimeter to measure the output of the power supply. There are several power supplies of GW Instek with on/off delay timer function. Please also check whether the output has a time delay because this function is turned on.

If the power supply still has no output after the above steps, please contact your nearest GW Instek Service Center to arrange for the instrument to be repaired. 

Service Support:

Q9 gw_product_detail_bar.png gw_product_detail_bar.png APS-7000 Invalid License


When using [User Special Function]->, select option 5. Add New Module and a message “ Invalid License” pop up



Check if the firmware version is too old? If it is lower than V2.10, please update to this version

1 Download the firmware version V2.10, there are a total of three files gw.sbt





2 Create a GW folder in the root directory of the USB Flash Drive formatted as FAT-32.

3 Copy the downloaded file gw.sbt to the \gw folder of this USB Flash Drive

4 Insert the USB Flash Drive into the USB port on the front panel of the APS

5 Press MENU

6 Turn the knob to 11. Special Function and press Enter

7 Enter the password "5004"


8 Turn the knob to 1. Update Firmware and press Enter, there will be no screen update for a while

9 Turn the knob to 2. Update Boot and press Enter, there will be no screen update for a while

10 Turn the knob to 3. Update Kernel and press Enter, there will be no screen update for a while


Q10 gw_product_detail_bar.png gw_product_detail_bar.png The specifications does not match the real accuracies.

Regarding to verify the power supply specifications please make sure the power supply is powered on at least 30 minutes,within +20℃ ~ -30℃.

Q11 gw_product_detail_bar.png gw_product_detail_bar.png I can not turn on the output (the Output key does not respond).

The following scenarios are possible:The following scenarios are possible:

• The rear panel remote control terminal is in the Off position. In this case, set it to the On position or deactivate remote control. For details, please refer see our user manual page39.

• The OVP setting switch on the rear panel is on the SET side. In this case, set the switch to the Normal side.

•The OVP indicator is red. In this case, change the OVP setting to higher value or remove the over voltage condition. 

*Note that in several conditions, the Output key automatically turns Off to avoid harmful condition. For details, please refer our user manual.

Q12 gw_product_detail_bar.png gw_product_detail_bar.png How to use auto running operation?

Auto Running Operation The function must be used together with the DELAY setting which is defined as the operation delay time of next running operation. The Delay function is workable only under Auto Running operation. Auto Running Operation The function must be used together with the DELAY setting which is defined as the operation delay time of next running operation. The Delay function is workable only under Auto Running operation. 

1)Delay time setting: Press [DELAY] to set the panel operation to Delay time setting selection. 

2)The setting and store of very group of data: A group setting includes the Output range, Output voltage value, Output current value, Over Voltage protection level, Over Current protection level, Over Voltage status (ON/OFF), and Delay time. User can proceed the setting and store it to the memory bank group by group up to 100 groups maximum. 

3)Recall range setting (Auto running operation range): Regarding the setting description, please refer to AUTO RANGE operation. 

4)Enter AUTO mode by pressing [AUTO], now, the operation is in the auto running function by pressing [OUTPUT]. 

5)Under this mode, press [SHIFT][AUTO INFO] can monitor the current operation setting address and operation time.