

“We've been using the Chroma 63208 Electronic DC Load for a number of applications. The unit has been very intuitive and easy to use. More importantly, it has saved us a tremendous amount of time and has improved our data collection methodology.”
~Edward West, President, Mission Motors
The Chroma Electronic Loads 63200 series are designed to test DC power supplies, power electronic devices, automative battery and components testing. The high power ratings, parallel and synchronization capabilities make them the ideal tool for testing high power UUT's such as SMR's, UPS's, batteries, and fuel cells.
Chroma electronic loads 63200 series provide constant current, constant resistance, constant voltage and constant power modes.
The CC and CR mode load simulation is helpful to test whether the output voltage of the UUT remains stable or regulated under different load conditions. For battery chargers, CV mode may help to change the output voltage of a charger and therefore can test if the battery charger has the correct charging current corresponding to its own output, or more precisely, the battery voltage. If the UUT is a battery, the electronic load is able to simulate the behavior of the device that uses the battery. For many of the battery discharge applications, power consumption patterns need to analyzed. The constant power or CP mode is ideal for these applications.

For low voltage/high current applications, the 63200 series is available with a low voltage, which provides ultra low voltage operation and in many cases can compensate for large voltage loss in the input wiring.
The 63200 series loads use a current close loop design, and connects all power MOSFET devices in parallel to insure high accuracy load control with minimal drift (less than 0.15% of the current setting). The MOSFET technology keeps the input impedance to a minimum and enables the load to draw very high current even at very low voltages. For example, the model 63209 is capable of drawing 1000A at only 1V input.
The Chroma 63200 series have a built in the 15-bit precision A/D converter, thus can achieve 0.05%F.S., 0.1%F.S. and 0.3%F.S. accuracy for voltage, current and power measurements respectively. They can be displayed simultaneously on three big LED readouts for the user's convenience. In additional to the standard measurements, the 63200 series also provides voltage and current monitor outputs, which are useful when the user needs to monitor the voltage and current waveform via a scope.
Modern electronic devices operate at very high speeds; therefore ,it is important for an electronic load to perform well during the transient and dynamic testing. To satisfy these testing applications, the 63200 loads offer outstanding high speed, programmable dynamic load simulation and control capabilities. The figure below shows the programmable parameters of the 63200 load modules. The programmable slew rate makes the simulation of transient load changes demanded by the requirement of real life application possible. The internal waveform generator of 63200 is capable of producing a maximum slew rate of 25A/μS (63208), and dynamic cycling up to 20kHz. Its' dedicated remote load sense and control circuitry guarantee the minimum waveform distortion during continuous load changes.

When higher power is required, it is common to parallel two electronic loads together to draw higher current. The 63200 series high power loads have smart Master / Slave control mode. When the loads are set to Master / Slave mode, users can program the loading (CC mode only) on master unit. The loading current values of the slave units will be calculated and downloaded by master unit automatically. In short, unlike traditional designs, users may consider several load units that work under Master / Slave mode as a single load unit.

The 63200 series electronic loads can be controlled by an external analog control signal, which is generated by any kind of signals or an arbitrary waveform generator. Thus, it is capable of simulating any loading waveform observed in the field within the load specifications.

Chroma's 63200 series electronic loads can also simulate a short circuit condition. The load can short a DC Power Supply or any power supplies that have a built in current limit function, and measure their short circuit currents so that users can verify if the UUT current limit is functional.
Chroma's 63200 Series DC Loads provide a unique surge load simulation capability which allows users to overdrive the loads up to 2.7 times their rated power for short periods. This feature is ideal when the average power required by the UUT is low compared to short-term peak power demands. Plasma Display Panel (PDPs) testing is one of the typical applications, others include battery 3C discharge, breaker & fuse over rating (300% to 1000%) tests, car engine startup simulation and DC motor startup simulation.
The amount of surge loading available using the 63200 loads is related to the initial loading conditions. Figures 1 and 2 show the relationship of the initial state (Load_Low under Dynamic mode) and the maximum acceptable overdrive power. Under this operation, the load will display an Over Power Protection Alarm (OPP) and will disable the load current if the user violates the maximum surge load capability showed in the figures.
Note 1: The Initial state under Static Mode should last at least 1 second.
Note 2: This surge load capability will be regulated by the temperature de-rating characteristics. (Refer to Note 1 in Specifications)
Note 3: Examples below assume the use of the Model 63201 load with a
continuous rating of 2600W/300A/1-80VDC
Example 1: STATIC LOADING
Example 2: DYNAMIC LOADINGThe 63200 Loads include a unique timing & measurement function allowing for precision time settings and measurements in the range of 1s to 99999s. This feature allows users to set a final voltage & timeout value for battery discharge testing and similar applications.
For example, Figure 3 shows that the 63200's internal timer can be initiated automatically when the battery voltage falls below a preset value. The timer will continue counting until the second preset voltage value is reached.

Power supplies have played a critical role in electrical and electronic devices. They have diversified into several different configurations for different applications. For example, AC/AC power supplies are used for UPS and AVR, AC/DC power supplies are used for PC power supplies, and DC/AC power supplies are used for inverters that transfer battery power to AC for home appliances. Lastly, DC/DC converters are widely used in battery powered devices such as cellular phones and laptop computers. With four different load modes, Chroma 63200 series electronic loads are capable of testing many different DC output power supplies directly or via a rectifier. They can also be used to test the AC output power supplies.

Almost all modern electronic equipment have a built in power supply. Therefore, a DC electronic load is an important instrument for these devices during the R/D and Q/A phases. For example, A/D, D/D and D/A stages are normally integrated in a UPS. The Chroma 63200 electronic loads are helpful in testing the internal A/D and D/D boards of UPS's.
For most applications, power consumption patterns are constant power. Therefore, the CP mode of the 63200 series electronic loads is ideal to use as a discharge load for battery testing.
Chroma 63200 series electronic loads provide GPIB, RS-232C and RS-485 PC controllable interfaces. The external waveform simulation and voltage / current monitoring capability make Chroma 63200 family ideal for automatic system integration.
Our experienced sales engineers can help you select the right instrument for your application. Contact Chroma Systems Solutions today!
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