The QPX600D can be operated as two entirely independent power supplies, each with its own comprehensive graphic LCD display. Alternatively multiple isolated tracking modes are available including ones intended for series and parallel operation which provide metering of total voltage or total current respectively.
Tracking Modes:
V2 set = V1 set
V2 set = N% x V1 set, where N can be between 5% and 2000%.
V2 set = V1 set, I2 set = I1 set. Additional display metering shows the total current flowing (I1+I2 actual). This mode is intended for parallel wiring of the outputs.
V2 set = V1 set, I2 set = I1 set. Additional display metering shows total voltage generated (V1+V2). This mode is intended for series wiring of the outputs.
Up to 160V or 100A
The combination of PowerFlex+ regulation with series or parallel wiring of the outputs and the use of smart tracking and metering, enables a higher voltage or higher current single output power supply to be simulated.
Bench or Rack Mounting
The QPX600D is housed in a 350mm (13¾”) wide case suitable for use on the bench-top. Output and remote sense terminals are mounted on the rear panel along with the analog and logic interface connectors and, on the QPX600DP, the bus interface connectors. The power supply is 3U high and a rack mounting kit (RM310A) is available as an option.
Independent or Simultaneous Output Control
The Both On and Both Off buttons are in addition to the individual switches for each output, and allow both outputs to be turned on or off synchronously by a single button press.
Synchronous switching of the outputs is of increasing importance for circuitry which can lock-up or even be damaged if one voltage rail is present without the other.
Power Calculation
The meter for each output can be set to show the total power currently being provided to the load (V x A) to a resolution of 0.1 watts. The power is shown in addition to the voltage and current values.
Low Resistance Calculation
The meter for each output can be set to show the equivalent resistance of the load by displaying voltage divided by current.
Low resistance measurements using a DMM utilize a low excitation current and suffer from thermal emf errors and other low voltage effects. This function enables low resistance measurements to be made at high currents by using the remote sense terminals to create a four terminal connection.
This can give much more reliable results for certain component types, such as magnetics, which operate at ampere levels.
QPX1200DP - USB, RS-232, LAN & GPIB
Graphic Display For Clarity and Ease of Use
The QPX600D incorporates two high resolution graphic LCDs capable of showing numbers and text in a variety of sizes. The standard display mode shows voltage and current in large characters along with text annunciators such as CV mode and Output On.
When settings are being changed, a dual display of parameters is used enabling existing and new settings, or actual and limit values to be viewed simultaneously.
A similar arrangement is used with smart metering for series or parallel operation. More complex functions are provided with text prompts or complete selection menus.
Current Meter Averaging
When measuring rapidly varying loads it can become difficult to get useful readings from the current meter. By selecting meter averaging, the reading is stabilized by averaging the last four readings to reduce the speed and extent of the variation.
Numeric or Rotary Entry
Voltage and current levels can be set directly via the numeric keypad. Alternatively settings can be changed via the jog wheel at user selectable increments.
Multiple Settings Stores
Non-volatile stores are incorporated for rapid recall of voltage and current settings and are useful for repetitive testing applications. Separate stores are provided for each output.
OVP and OCP trips
Variable trips for over-voltage and over-current are provided on each output. Unlike a limit setting, the trip setting turns the output off and provides a different level of protection. For example, when repetitively testing a unit which normally takes a peak current of 10A, the current limit could be set to 11A and the OCP to 10.1A to ensure that a faulty unit will trip the supply off and not be damaged by over dissipation. The output trip can also be activated by other fault conditions including over temperature and remote sense mis-wiring. The cause of the trip is shown on the display.
Analog and Logic Interfaces
Both models incorporate analog interfaces for voltage control of both output voltage and output current (non-isolated)
The control voltages are digitized to control the PSU and the scaling can be selected as 0 to 5V or 0 to 10V for zero to full scale. Monitor outputs for voltage and current are also provided, and can similarly be selected as 0 to 5V or 0 to 10V.
An opto isolated logic control signal is provided for control of output on/off. This can be menu selected as true = output on, or true = output off. An opto isolated open-collector logic output signal is also available. This can be menu selected as true or false for output enabled or disabled, current limit, power limit, or any fault trip.
QPX600DP - Comprehensive Bus Remote Control
To meet a wide variety of needs, the QPX600DP adds a comprehensive array of digital bus interfaces. RS-232, USB, GPIB and LAN (Ethernet) with LXI support are all provided as standard. Each of the digital bus interfaces provides full control of voltage, current, output on/off and set-up, plus read-back of voltage, current and status. The interfaces are at ground potential and are opto-isolated from the output terminals.
The GPIB interface is compliant with IEEE-488.1 and IEEE-488.2. Currently GPIB remains the most widely used interface for system applications.
An RS-232/RS-423 interface is provided for use with legacy systems. This type of serial interface remains in common usage and is perfectly satisfactory for the control of power supplies because data speed is not an issue.
USB provides a simple and convenient means of connection to a PC and is particularly appropriate for small system use. A USB driver is provided which supports Windows 2000, XP , Vista and Windows 7
The LAN interface uses a standard 10/100 base-T Ethernet hardware connection with ICMP and TCP/IP Protocol for connection to a Local Area Network or direct connection to a single PC. This interface supports LXI and is highly appropriate for system use because of its scalable nature and low cost interconnection.
The LAN interface is compliant with LXI class C. LXI (LAN eXtensions for Instrumentation) is the next-generation, LAN-based modular architecture standard for automated test systems managed by the LXI Consortium, and is expected to become the successor to GPIB in many systems. For more information on LXI and how it replaces GPIB, or operates along side it.
IVI Driver
An IVI driver for Windows is included. This provides support for common high-level applications such as LabView*, LabWindows*, and HP/Agilent VEE*.
* LabView and LabWindows are trademarks of National Instruments. HPVEE (now Agilent VEE) is a trademark of Agilent Technologies.
* Windows is a trademark of Microsoft.
The QPX1200L is identical to the QPX1200SP but omits the GPIB interface.