DC Electronic Loads are used for design, manufacturing and evaluation of DC power supplies, batteries, and power components. Other applications include fuel-cell and photovoltaic cell test.
The DC Load can operate under the following modes:
- Draw a constant voltage from a DC source.
- Draw a constant current from a DC source.
- Draw a constant power from a DC source.
- Present a constant resistance to the DC source (this behavior simulates a perfect resistor whose resistance doesn't change as a function of current or voltage).
8500 Series DC Electronic Loads
Versatile & Economical DC Electronic Loads
The 8500 series Programmable DC Electronic Loads can be used for testing and evaluating a variety of DC power sources. Their wide operating ranges of up to 500 V and 240 A, flexible operating modes and excellent measurement accuracy make the 8500 series well suited for characterizing DC Power supplies, DC-DC Converters, batteries, fuel cells and solar cells.
The loads can operate in CC, CV, CR or CP mode while voltage/current or resistance/power values are measured and displayed in real time. Load terminals are isolated and floating. Over temperature, over power, over voltage, over current and reverse polarity protection will help protect your valuable prototype and circuits.
The DC loads are easy to use. All parameters can be set quickly and precisely from the front panel, or programmed via USB interface.
When selecting a DC load, it is important to consider not only voltage and current requirements, but also power ratings. The power used when testing must fall within the hatched region for the appropriate DC load.
Some applications may require high voltage/low current and low voltage/high current which a single load may not be able to handle. B&K Precision’s broad range of DC loads will allow you to select the optimal model for your requirements.
Low voltage operation
The 8500 series can operate well below 1 V which is important for low voltage application such as fuel cell and solar cell testing. All models can regulate (provide a stable input) down to 0.1 V. Model 8518, due to its particularly low input resistance, can operate at full scale current of 240 A at 1.2 V.
Typical minimum operating voltage at full scale current:
8500 Series Panel Description
The numeric keys and rotary knob provide a convenient interface for setting the operating mode and desired current/voltage/resistance levels quickly and precisely. Voltage and current can be set to a maximum resolution of 1 mV and 0.1 mA respectively (models 8500 and 8502 only). Up to 25 different instrument setups can be stored and recalled from internal memory.
- High resolution, easy to read display
Displays set values and measured values. Current/voltage and power/resistance displays can be toggled. Display resolution for current and voltage is user-selectable. Maximum resolution for model 8500 and 8502 is 1 mV/ 0.1 mA.
- Convenient data entry
Rotary knob for quick analog-style control. Turn to adjust a setting value. Press to toggle measurement display mode.
- Numeric keypad
Conveniently enter set values directly and access secondary functions.
- Function keys
Activate current, voltage, power, or resistance modes and scroll through menus and options.
- Front panel load terminals
Connect to device under test. Hex-head screw
- Air vents
Temperature-controlled fan expels air through these vents to keep the temperature constant inside the system.
- Trigger and remote sensing terminal block
Connect sensing lines to this terminal to compensate for voltage drops due to load wire resistance. This terminal block also contains the two connections for the remote TTL trigger input signal.
- Interface connection
Serial interface connector for USB communication.
- Voltage switch
Line voltage selection switch (110 VAC or 220 VAC).
Flexible operating modes
CC, CR, CV and CP mode
In Constant Current (CC) mode, the load will sink a current according to the programmed current value regardless of the input voltage. (CC) mode can be used for load regulation testing of DC power supplies or for characterizing the discharge profile of a battery.
Constant Power (CP) mode simulates a load whose power consumption is independent of the applied voltage. Constant Power (CP) mode is useful for battery testing and simulating a realistic discharge curve.
In Constant Voltage (CV) mode, the load will attempt to sink enough current to control the source voltage to the programmed value. This mode is suitable for testing battery chargers. In Constant Resistance (CR) mode, the load will sink a current linearly proportional to the input voltage in accordance with the programmed resistance. Unlike conventional resistors, the load resistance stays constant regardless of the power level.
The 8500 series offers a variable frequency generator which can be used in all operating modes. The DC load will toggle between 2 preset levels at a frequency between 0.1 Hz to 1 kHz, either continuously or controlled by a trigger.Transient generator
Triggering is used to allow synchronization of the DC Load's behavior with other events. You can generate a trigger event by front panel keystroke, by applying an external TTL signal to the back panel terminal or by sending a commands over the serial bus. The trigger can be used in pulse mode, transient mode, list mode and works in CC, CR, CV and CP modes.
Remote control and application software
The DC loads can be remotely controlled from any PC with USB interface, allowing the user to fully program and monitor all parameters. USB to TTL serial converter cables are included. For users wanting to write their own custom software, a set of example programs are available for download on the B&K Precision website.
A list of command sequences can be stored in non-volatile memory and executed independently of a computer. Execution in list mode greatly reduces command processing time and computer interaction during product testing. The command sequence can be entered manually from the front panel or downloaded from a PC via USB interface.
The included Application Software supports front panel emulation of the load and includes a battery test application which provides A*hr rating of a battery and adjustable ending voltage levels (safety voltage). Whether you are designing a device with Nickel-Metal Hydride or Lithium-Ion batteries, the 8500 series have the capabilities to test their characteristics.