Programmable DC Electronic Loads
Circuit Specialists carries top-quality programmable DC electronic loads for emulating real world applications while testing, e.g., power supplies, batteries, or fuel cells. These electronic loads perform better than a conventional ohmic load resistor by dependably keeping constant voltage, resistance,current, and power settings. The electronic loads' controls are very intuitive, their backlit LCD displays are clear and easy to read, and they have heavy-duty output terminals.
Basics of Electronic DC Loads:
To select a DC load that best fits the desired application, the user should obviously consider the task or tasks that the dc load is going to be used for.
Some things to consider when selecting a DC load are:
- What are the lowest voltage & highest voltage points that you need the DC Load to read?
- What kind of measurements are needed ? ( RMS measurements, Digitized etc)
- What is the highest current operating point that the DC load may be needed to read?
- Will the DC Load be testing one unit per test or do you need to test many units?
- Does the DC Load have front panel connections? This may be critical to reduce cable drop and increase the accuracy of the DC load
- Can your DC load be quickly reconfigured for changing applications?
Once the end user of the DC load has determined which tests are required, an appropriate DC load may be selected. The four major modes of operation for a DC load are Constant Current ( CV), Constant Voltage (CV) Constant Resistance ( CR) and Constant Power ( CP). A well designed DC load will always control the current. No matter what mode the DC load is in, it is always controlling the current which will allow a test engineer to set a current level that the DC load will draw regardless of any changes in voltage.
Constant Resistance (CR) mode) allows the user to set a resistance value into the DC Load and then the load will adjust the current draw inversely to compensate for any change in the testing voltage. Constant Voltage ( CV) model allows the user to set a voltage into the DC load that he wants to remain constant. The DC Load will sink the necessary current to keep the voltage at the level set into the DC load. Constant Power (CP) mode will allow the user of the DC load to set a wattage level that is required for the test. Then the DC load will adjust the current draw proportionately to compensate for any changes in the voltage. These settings of the DC load will all stay true unless there is an event that triggers one of the protection modes.
DC loads usually include standard PC interface features including RS-232 and USB. Also, GPIB may be available. Using a PC to control and record testing data through a DC Load can help with setting control parameters of the DC load as well as recording all events occurring during the testing period.
Wayne Thorpe, President
Circuit Specialists, Inc.