The PSW-Series is a single-output multi-range programmable switching DC Power Supply covering a power range up to 1080W. This series of products include fifteen models with the combination of 30V, 80V, 160V, 250V, and 800V rated voltages and 360W, 720W and 1080W maximum output powers. The multi-range feature allows the flexible and efficient configuration of voltage and current within the rated power range. As the PSW-Series can be connected in series for maximum 2 units or in parallel for maximum 3 units, the capability of connecting multiple PSW units for higher voltage or higher current output provides a broad coverage of applications. With the flexibility of multi-range power utilization and series/parallel connection, the PSW Series significantly reduces the user’s investment for various power supply products to accommodate the projects with different power requirements.

The CV/CC priority selection of the PSW-Series is a very useful feature for DUT protection. The conventional power supply normally operates under CV mode when the power output is turned on. This could bring a high inrush current to the capacitive load or current-intensive load at the power output-on stage. Taking the I-V curve verification of LED as an example, it becomes a very challenging task to perform this measurement using a conventional power supply. With LED connected to a power supply under CV mode as the initial setting, when the power output is turned on and the voltage rises to the LED forward voltage, the current will suddenly peak up and exceed the preset value of current limit. Upon detecting this high current, the power supply starts the transition from CV mode to CC mode. Though the current becomes stable after the CC mode is activated, the current spike occurred at the CV and CC crossover point may possibly damage the DUT. At the power output-on stage, the PSW-Series is able to run under CC priority to limit the current spike occurred at the threshold voltage and therefore protect DUT from the inrush current damage.

The adjustable slew rate of the PSW-Series allows user to set for either output voltage or output current a specific rise time at the low to high level transition, and a specific fall time at the high to low level transition. This facilitates the characteristic verification of a DUT during voltage or current level changes with controllable slew rates. The manufacturing tests of lighting device or large capacitor during power output-on are mostly associated with the occurrence of high surge current, which can greatly reduce the life time of the DUT. To prevent inrush current from damaging current-intensive devices, a smooth and slow voltage transition during power on-off can significantly reduce the spike current and protect the device from high current damage.

The OVP and OCP are provided with the PSW-Series. Both OVP and OCP levels can be selected, with default level set at 110%, of the rated voltage/current of the power supply. When any of the protection level is tripped, the power output will be switched off to protect the DUT. The PSW-Series provides USB Host/Device and LAN interfaces as standard and GPIB-USB adaptor as optional. The LabView driver and the Data Logging PC software are supported on all the available interfaces. An analog control/monitoring connector is also available on the rear panel for external control of power On/Off and external monitoring of power output Voltage and Current.
 

C.V/C.C Priority Selection

The PSW series has C.C and C.V priority mode which sufficiently satisfies market demands. For special application requirements and specific demands, power supply system must be equipped with advanced functions. The C.C. priority mode of the PSW series allows power supply to operate under C.C. mode instead of C.V mode during the transient output so as to effectively protect DUTs. The conventional power supply normally operates under C.V mode when output is turned on that will instantly produce a high inrush current on load with diode characteristics. By using the I-V curve of LED as an example, the conventional power supply cannot conduct the related test and measurement operation. Connect LED with power supply under C.V mode and activate output operation. When the voltage exceeds the forward voltage of LED, current will abruptly increase and exceed the preset current limit. Once the inrush current is detected, power supply will convert C.V mode into C.C mode. After the transition, current seems to be more stable. However, the peak current at the crossover of C.C. and C.V is likely to induce damage to DUTs. The C.C. priority mode of the PSW series allows power supply to operate under C.C. mode to avoid peak current during the transient output so as to effectively prevent DUTs from being damaged by inrush current.

Under the conventional C.V mode, inrush current and surge voltage appeared at forward voltage (Vf) of LED	Under C.C priority mode, inrush and surge voltage are effectively restrained.

V-I Characteristics for Diode	GDS-3354 digital oscilloscope is used to test LED under C.V priority mode and C.C priority mode respectively.

Adjustable Slew Rate

The PSW-Series has adjustable slew rates for the level transition of both Current and Voltage. This gives the PSW-Series power supply the ability to set specific rise time and fall time of the Voltage and Current drawn from the power supply to verify DUT performance during the Voltage / Current level transition. The feature also provides the benefit to slow down the voltage transition at the power output-on to protect DUT from inrush current damage. This is especially useful for the test of heavy-current-drawn devices like capacitors.

The Adjustable Rise Time of the PSW 30V

	The Adjustable Rise Time of the PSW 800V

Bleeder Control Circuit

The PSW power supply series has a bleeder control circuit which is in parallel with the output terminal. When power is off or load is disconnected, bleeder resistor will discharge the filter capacitor. Without a bleeder resistor, the filter capacitor of power could still be charged with electricity that poses a potential danger. In addition, for ATE system, bleeder resistor allows PSW to bleeder current rapidly so as to prepare itself for the next operation.

Output On/Off Delay

The Example of Output On/Off Delay Control for Multiple PSW Units

The output on/off delay feature enables the setting at a specific time delay for output on after the power supply output is turned on, and a specific time delay for output off after the power supply output is turned off. When multiple PSW units are used, the on/off delay time of each unit can be set respectively referring to fix time points.
 

External Analog Remote Control Terminal

On the rear panel of the PSW Series power supply, a 26-pin analog control terminal is designed to perform remote control and monitoring functions. External voltage or resistor can be utilized to set output voltage and current. The power supply output on/off control and master power shut-down can also be controlled by using the external switch. The analog control terminal is complied with the Mil 26-pin connector (OMRON XG4 IDC plug) standard.

(1) External voltage controls voltage/current output 
(2) External resistor controls voltage/current output
(3) External switch controls output
(4) External switch controls master power shut-down
(5) External DMM measures voltage output
(6) External DMM measures current output

Multi-Range Operation In the comparison with the maximum power output of the conventional power supply that is calculated by the maximum output voltage multiplies by the maximum output current, the PSW series has a unique characteristic of multi-range output (voltage x current). This distinguishing feature, under the same maximum power output range, can output a higher voltage with a smaller current and vice versa. For instance, for a conventional power supply with a maximum power output of 720W, the maximum voltage and current outputs are likely to be 90V and 8A respectively. Comparatively, PSW 250-9, with the maximum power output of 720W, provides voltage and current output ranges of 0~250V and 0~9A. The maximum current of 9A will be provided when the maximum voltage is 80V and the maximum voltage of 250V for current of 2.88A. The following diagrams illustrate the characteristics of PSW output voltage and current. PSW 30V Series Operational Curve PSW 80V Series Operational Curve PSW 160V Series Operational Curve PSW 250V Series Operational Curve PSW 800V Series Operational Curve   Series and Parallel Connections To increase power output capacity, the PSW-Series could be connected in Series mode to perform double voltage rating or in parallel mode to perform triple current rating for each model and maximum power is 3.24KW. With Multi-Range feature and Series/Parallel connection capability, the PSW-Series is a high power density and cost-effective equipment.   Series Connection Parallel Connection PSW 250V/800V only support parallel connections and maximum units in parallel is three