Zero volt on load multi-channel electronic load IT8700P+ emerges
Zero-volt load means that the electronic load can output a rated full current at a very low input voltage, and the current can be as high as hundreds of amperes. The electronic load has an unavoidable minimum internal resistance due to the conduction-drain-source internal resistance of the field effect transistor, and requires a certain minimum DC input voltage (UMIN) to enable the load to absorb the full rated current. Below this minimum operating voltage, the load current will decrease linearly. Usually below 3V, the load transistor is in the saturated working range, the current control ability becomes weaker, and the dynamic response becomes worse. The power supply voltage must be greater than the minimum operating voltage of the load, and the voltage drop of wires, relays, connectors, etc. under high current needs to be considered.
In order to make the electronic load run at full rated current even when it is lower than UMIN, in addition to purchasing an expensive four-quadrant power supply, you can also use an auxiliary power supply to compensate UMIN and extend the working range, but the auxiliary power supply will bring the system In addition, it is necessary to select a higher power load to consume the power of the auxiliary power supply. In addition, the auxiliary power supply brings potential voltage reverse bias risks to the power supply under test.
【Common applications with zero-volt load】
Single cell testing, e.g. 3.6 V lithium cells
Fuel cell production end test
Testing of voltage characteristic curves down to 0V
Zero-volt load multi-channel electronic load
IT8700P+ multi-channel DC electronic load module has ultra-low conduction internal resistance, and has three current operating range settings. Under the small and medium range range, the minimum load voltage is <0.1V. The load voltage is <0.5V, and the lower input impedance can be obtained after parallel operation. It is suitable for testing fuel cells, super capacitors, solar cells, DC-DC converters and other low-voltage and high-current electronic devices.
The IT8700P+ multi-channel electronic load adopts the form of a host frame combined with a module. The new IT8700P+ module can be mixed with the IT8700P module. The modules can be master-slave paralleled. Up to 16 channels can be connected in parallel. The current can reach 960A and the power can reach 4800W.
A power supply customer of ITECH needs to test the dynamic and static working characteristics of its low-voltage high-current DC-DC module at 0.7V, 320A:
The static test is shown in Figure 1:
After 6 IT8733P+ (80V/120A/600W) modules are paralleled, they can stably load 320A at 0.7V. DC-DC modules with low-voltage and high-current output can be applied to LED TVs, solid-state RF amplifiers, ion colliders, etc.
Figure 1
The dynamic characteristics are shown in Figure 2:
After paralleling, the rising speed can reach 30A/us, and the fastest speed of 0~320A can reach 12us. It is worth noting that because the current speed is too fast, the inductance on the wire cannot be ignored, and a low inductance test line can be used to reduce the voltage drop.
Figure 2
The IT8700P+ module is divided into single-channel and dual-channel versions. There are 9 models in the whole series. Currently, 3 models have been released, and other models will be launched one after another.
IT8700P+ single channel module model
IT8700P+ dual channel module model
IT8700P+ series multi-channel DC electronic load is a high-precision, high-speed zero-volt load multi-channel electronic load, which is suitable for various occasions such as system integration, research and development, production lines, and metrology institutes. For more detailed information and specifications, you can log on to ITECH's official website www.ichate.com or call 4006-025-000 for product consultation.
