LD SERIES
Electronic DC Loads
80A-80V-400W or 16A-500V-400W Constant current, resistance, power, voltage and conductance Transient generator, variable slew rate, soft start Current monitor output, analog remote control USB, RS-232, GPIB and LAN interfaces
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LD SERIES Key Features
COMPACT ELECTRONIC DC LOADS
The LD series features electronic loads which are suitable for
testing and characterising a wide variety of dc power sources. They can be used to investigate the behavior of many different types of power source such as PFCs, batteries and solar cells, as well as electronic power supply units. The wide voltage/current range, multiple operating modes and built-in transient generator give them versatility to offer test solutions from the design laboratory through to the component test area.
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| LD400 & LD400P | LDH400P | |
| Max Power range | 400W (600W short term) | 400W |
| Max Current | 80A rear panel 30A front panel | 16A |
| Operating range | 0 - 80V | 10 - 500V |
| Isolation voltage | ±300Vdc | CAT II (300V) |
| Operating modes | CC,CP,CR,CG,CV | CC,CP,CR,CG |
LOW MINIMUM OPERATING VOLTAGE
The LD400 can operate at voltages below 500mV for currents up to 10 amps. At higher currents the fixed minimum resistance (typically better than 25mΩ) gradually raises the minimum operating voltage, but it remains below 1 volt up to 40 amps and below 2 volts up to 80 amps. This low operating voltage allows it to be used for many low voltage applications for which other electronic loads are unsuitable.
600 WATTS INTERMITTENT POWER
The LD400 can operate at power levels up to 600 watts for periods of up to 1 minute. Short term loading can be sufficient for many testing applications and significantly extends the usefulness of the LD400.
PFC TEST EXAMPLE
CAT II (300V) RATING
The LDH400P load inputs are rated to CAT II (300V), this allows the direct testing of PFCs and mains connected power supplies to be simplified using the LDH400P by eliminating the need for an isolation transformer, saving bench space and cost.
LD SERIES Remote control
ANALOG REMOTE CONTROL
The LD series incorporates analog remote control for all modes of operation. When “external voltage” is selected the level becomes linearly proportional to the voltage applied to the remote control inputs on the rear panel.
A waveform can be used as the control voltage allowing complex load conditions to be simulated using, for example, an arbitrary waveform generator, such as the Aim-TTi TGF3000 series or a true arbitrary generator from the TGA series.
Alternatively, a logic signal can be used to switch between levels. When “external TTL” is selected, the level is switched between the two defined levels in response to an external logic signal.
COMPREHENSIVE BUS REMOTE CONTROL
To meet a wider variety of needs, the P models in the LD series add a comprehensive array of digital bus interfaces. USB, RS-232, GPIB and LAN with LXI support are all provided as standard.
Each of the digital bus interfaces provides full control and read-back of settings and status. The interfaces are at ground potential and are opto-isolated from the terminals.
A standard RS-232/RS-423 interface is provided for use with legacy systems with a baud rate of 9600. The serial interface remains in common usage and is perfectly satisfactory for the control of load devices .
USB provides a simple and convenient means of connection to a PC and is particularly appropriate for small system use. A standard USB 2.0 driver is provided which operates as a virtual COM port and supports Windows 2000 and above including Win 8 and 10.
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 1.4 LXI core 2011 and is highly appropriate for system use
because of its scalable nature and low cost
interconnection.
LABVIEW & IVI DRIVER
An IVI driver for Windows is included with all P models in the LD series. This
The GPIB interface is compliant with provides support for common high-The LAN interface is LXI compliant. LXI
IEEE-488.1 and IEEE-488.2. GPIB remains level applications such as LabView*, (LAN eXtensions for Instrumentation) is
a widely used interface for system LabWindows*, and KeysightVEE*. the next-generation, LAN-based modular
applications. The interface subsets architecture standard for automated test
provided are: systems managed by the LXI Consortium,
SH1, AH1, T6, L4, SR1, RL2, PP1, DC1, DT0, and is expected to become the successor C0, E2.
to GPIB in many systems. For more information on LXI go to: www.aimtti.com/go/lxi
* LabView and LabWindows are trademarks of National Instruments.KeysightVEE is a trademark of Keysight Technologies. Windows is a trademark of Microsoft.
| MODEL | LD400 & LD400PP | LDH400P |
| TRANSIENT CONTROL | ||
| TRANSIENT GENERATOR | ||
| Pulse Repetition Rate: | Adjustable from 0·01Hz (100 seconds) to 10kHz | |
| Pulse Duty Cycle: | 1% to 99% (percentage of period at Level A) | |
| Setting Accuracy: | ±1 % | |
| Slew Rate Control: | The slew rate control applies to all changes of level whether caused by manual selection, remote control or the transient generator. The level change is a linear slew between the two level settings. The range available in each mode is shown previously. | |
| Setting Accuracy: | ± 10% (on linear part of slope, excluding high frequency aberrations) | |
| Variation in Level Settings: | ± 5 digits of specified setting resolution for present mode and range. | |
| OSCILLATOR SYNC OUTPUT | ||
| Connection: | Terminal block on rear panel. Opto-isolated open collector output conducts during Level B phase of internal transient generator. | Terminal block on rear panel. Lo terminal output grounded to chassis internally. TTL/ CMOS (5V) output. Conducts during Level B phase of internal transient generator. |
| Ratings: | Max offstate voltage: 30V. Collector current: 2mA (typical). | TTL/CMOS |
| DROPOUT VOLTAGE | ||
| The load will cease to conduct if the applied voltage falls below the Dropout Voltage setting; active in all modes. The Dropout Voltage setting is also the threshold for the Slow Start facility and acts as an offset voltage in Constant Resistance mode. | ||
| Setting Accuracy: | ± 2% ± 20mV | ± 2% ± 200mV |
| Slow Start: | If Slow Start is enabled, the load will not conduct any current until the source voltage reaches the Dropout Voltage setting; it will then ramp the controlled variable up (in CC, CP and CG modes) or down (in CR and CV* modes) to the Level setting at a rate determined by the Slew Rate setting. | |
| *LD400 & LD400P models only | ||
| METER SPECIFICATIONS | ||
| Display Type: | 256 x112 pixel graphic LCD with white LED backlight. | |
| MEASURED VALUES | ||
| Volts & Amps: | Measured values of current through and voltage across the load. | |
| Watt & Ohms: | Power and equivalent load resistance, calculated from Volts and Amps. | |
| Voltage Accuracy: | ± 0·1% ± 2 digits | ± 0·1% ± 0.02%FS |
| Current Accuracy: | ± 0·2% ± 3 digits | ± 0·2% ± 0.04%FS |
| CURRENT MONITOR OUTPUT | ||
| Output Terminals: | 4mm safety sockets on front panel or terminal block on rear panel. | BNC (chassis grounded) on front panel or terminal block on rear panel. |
| Output Impedance: | 600Ω nominal, for >1MΩ load (e.g. oscilloscope) | |
| Scaling: | 50mV per Amp (4V full scale) | 250mV per Amp (4V full scale). |
| Accuracy: | ± 0·5% ± 5mV | |
| CURRENT MONITOR OUTPUT | ||
| Common Mode Range: | ± 3V dc max (5) | Chassis ground referenced |
| Bandwidth Limit (-3dB): | - | 40kHz |
| MODEL | LD400 & LD400PP | LDH400P |
| PROTECTION | ||
| Excess Power: | The unit will attempt to limit the power to approx 430W; if this fails the unit will trip into the fault state at about 460 Watts. If intermittent mode operation in enabled, these levels are 610W and 630W. | The unit will attempt to limit the power to approx 430W; if this fails the unit will trip into the fault state at about 460W. |
| Protection Current: | The input is disabled if the measured current exceeds a user set limit. | |
| Excess Current: | The unit will trip into the fault state at nominally 92A. | The unit will trip into the fault state at nominally 20A. The unit is protected by fuses that protect the unit against currents that exceed 20A. This is primarily as a protection against high power sources with a current capability of >20A being connected to the load with reverse polarity. |
| Protection Voltage: | The input is disabled if the measured voltage exceeds a user set limit. | |
| Excess Voltage: | The unit will conduct a current pulse (to absorb inductively generated spikes) for 1ms at about 90V. The unit will trip into the fault state at nominally 106V. Surge suppressors will start to conduct above 120V. | The unit will conduct a current pulse (to absorb inductively generated spikes) for 1ms at about 510V. The unit will trip into the fault state at nominally 530V. Surge suppressors will start to conduct at typically 800V ± 20%. |
| Temperature: | The unit will trip into the fault state if the heatsink temperature exceeds safe levels. | |
| Reverse Polarity: | N/A | The unit will trip into the fault state if a reverse current is drawn that exceeds 200mA. The unit is protected by fuses that protect the unit against currents that exceed 20A. |
| REMOTE CONTROL (P MODELS ONLY) | ||
| EXTERNAL CONTROL INPUT CHARACTERISTICS | ||
| Connection: | Terminal block on rear panel. | Terminal block on rear panel. Lo terminal input grounded to chassis internally. |
| Input Impedance: | 400kΩ each input to load negative. | 10kΩ. Input protected against excess input voltages up to 50V. |
| Common Mode Range: | ± 100V to load negative. | Chassis ground referenced |
| EXTERNAL ANALOG VOLTAGE CONTROL | ||
| Operating Mode: | The applied voltage sets the operating level within the range. | |
| Scaling: | 4 Volts full scale. | 4 Volts full scale (250mV per Amp). |
| Accuracy: | ± 2% ± accuracy of range. | |
| Common Mode Rejection: | Better than -66dB | Better than -76dB |
| MODEL | LD400 & LD400PP | LDH400P |
| EXTERNAL LOGIC LEVEL (TTL) CONTROL | ||
| Operating Mode: | The applied signal selects between Level A and Level B settings. | |
| Threshold: | + 1·5V nominal. A logic high selects Level B. | |
| REMOTE DISABLE INPUT | ||
| Connection: | Terminal block on rear panel. Input to the LED of an opto-isolator through 1kΩ resistor. | |
| Threshold: | Apply >+3V to disable the load input. Max. 12V. | |
| GENERAL | ||
| AC Input: | 110V–120V or 220V–240V AC ±10%, 50/60Hz. Installation Category II | |
| Power Consumption: | 40VA max. Mains lead rating: 6A minimum. | 40VA max. Mains lead rating: 6A minimum. |
| Operating Range: | + 5°C to + 40°C, 20% to 80% RH | |
| Storage Range: | – 40°C to + 70°C | |
| Environmental: | Indoor use at altitudes up to 2000m, Pollution Degree 2. | |
| Cooling: | Variable speed fan. Air exit at rear. | |
| Safety: | Complies with EN61010-1 | |
| EMC: | Complies with EN61326 | |
| Size: | 130mm H (3U) x 212mm W (½ rack) x 435mm D | |
| Weight: | 5.7 kg | |
| Option: | RM460 - 19-inch rack mount kit | |
| SPECIFICATION NOTES |
|---|
| LD400 & LD400P Accuracy specifications apply for 18°C – 28oC, at 50W load power (in normal 400W mode), after 30 minutes operation at the set conditions; regulation specifies variation at other powers. Setting accuracies apply with slew rate at the ‘Default’ setting. |
| LDH400P Accuracy specifications apply for 18°C – 28oC, using rear panel terminals, after 30 minutes operation at the set conditions. Setting accuracies apply with slew rate at the ‘Default’ setting. |
| (1) In 600 Watt short-term operation mode the dynamic response is not specified, and both the slew rate and the transient oscillator frequency range are restricted. The slew rate limitation applies also to external voltage control. This mode is primarily intended for limited duration operation at a fixed level setting. (2) Slew Rate Ranges refer to the theoretical slope of the transition between two levels, regardless of whether that transition can be achieved when taking into account the level difference, the set transition duration, the minimum transition time, and the characteristics of the source. (3) Minimum Transition Time specification is an indication of the fastest available transition using a benign battery source and low inductance connections, with a minimum terminal voltage of 5V and a minimum current of 1A. The actual performance attainable with electronically regulated power supplies depends on the combination of source and load loop bandwidths and interconnection inductance. (4) Minimum Transition Time specification is an indication of the fastest available transition using a benign source and low inductance connections, with a minimum terminal voltage of 25V and a minimum current of 200mA. The actual performance attainable with electronically regulated power supplies depends on the combination of source and load loop bandwidths and interconnection inductance. (5) The common mode capability of the current monitor is to provide tolerance of voltage drops in the cables. The monitor negative must be connected at some point to the load negative circuit. |
Brochure Part No. 82100-1540 Issue 1
Thurlby Thandar Instruments Ltd. operates a policy of continuous development and reserves the right to alter specifications without prior notice.