Introduction： 3720A,3721A,3722A and 3723A Electronic Loads provide an adaptable, and functional asset wherever power sources need to be tested.These units are designed to provide high reliability, great performance, and ease of operation with multiple functionality. Features： 4 basic functions: CC, CV, CR, and CP ; and 8 basic test modes: CCL, CCH, CV, CRL, CRM, CRH, CPV, CPC High-speedsequence, high-speed transient, short-circuit, battery discharge and other auxiliary functions Minimum operating voltage is less than 0.6V at the load's full rated current Optional zero-voltage test accessories are available Programmable current slew rate Perfect protection assures high reliability in the most complicated of test environments Multiple groups of parameters and lists can be saved and recalled Ruggedized structure, exquisite user-friendly design and convenient operation Supports SCPI (Standard Commands for Programmable Instrumentation) and Labview, and provides necessary PC software High Reliability Protective circuitry provides over-current, over-voltage, over-power, over-temperature and reverse polarity protection to ensure the protection of the electronic load; A high-speed, power limiting circuit can limit input power rapidly when it is overloaded, thus there is no need to interrupt testing. Equipment adaptability to complicated operational environments is thereby greatly enhanced. A high-efficiency, intelligent cooling system can effectively reduce system temperature and enhance power density; The input binding posts with their innovative design are especially suitable for large current testing. They are easy to operate, reliable and durable; The specially ruggedized case with its rubber bumpers protects the load thus effectively prolonging the unit’s service life. Great Performance Circuit improvement greatly enhances the dynamic response of CR mode and widens the application scope of that mode; The innovative CP mode can test voltage sources, current sources, and effectively prevent short-circuits as well when the tested power is insufficient; Minimum operating voltage is less than 0.6V at the load's full rated current. With optional low-voltage testing devices, the maximum current can be achieved even though the input voltage is 0V. This is especially suitable for fuel cell, solar cell and other new energy test applications; By adopting an optimum design of calculation method and high-speed hardware circuitry, the D/A conversion rate can reach 100kHz. The overall smoothness of slope control has been raised, meanwhile, the timing precision and resolution of dynamic test and sequential test have also been improved; The 24 bit A/D and 17 bit D/A converters incorporated, provide this equipment with greatly enhanced setting and measurement resolution. Multifunction Equipped with four basic test functions: CC, CV,CR, CP; High-speed transient operation with separate high/low lever time and rising/falling time control; Powerful sequential test function; with a minimum step time of 10us; and a maximum step time of 10000s. Cyclic numbers can be adjusted freely and a sequence can be chained to another sequence to achieve even more complex test procedures; Providingshort-circuit test, battery discharge test and other auxiliary functions; Remote input terminal and external trigger input terminals are provided. The remote measurement can monitor the input signal automatically, and it is not necessary to change wiring or modify settings during operation; 10 groups of setup parameters can be saved, and providing automatic uploading of preset parameters; By supporting SCPI, it is easy to build an ATE (automatic test equipment) system that works with other programmable instruments via optional RS232, USB and GPIB interfaces. Easy Operation Design optimized for portability and rugged reliability; Logical keypad design and convenient test operation; Easy-to-set test parameters coupled with a powerful sequence editing function; All electronic calibration - therefore no need to dismantle the equipment-chassis; Firmware can be updated online. Specifications (The warm-up time is 30 minutes. Specifications indicate warranted performance in the 25°C ± 5°C region of the total temperature range). Model 3720A 3721A 3722A 3723A Input Ratings Current Voltage Power*1 0~30A 0~80V 250W at 40oC 0~40A 0~80V 400W at 40oC 0~20A 0~200V 200W at 40oC 0～30A 0～200V 350W at 40oC Input Characteristics Input Characteristics Minimum Operation Voltage@Full Scale Current 0.6V 0.6V 1.2V 1.2V Constant Current Mode LowRange Resolution Accuracy 0~3A 0.1mA 0.1℅+5mA 0~4A 0.1mA 0.1℅+5mA 0~2A 0.1mA 0.1℅+5mA 0~3A 0.1mA 0.1℅+5mA HighRange Resolution Accuracy 0～30A 1mA 0.1℅+10mA 0~40A 1mA 0.1℅+10mA 0~20A 1mA 0.1℅+10mA 0~30A 1mA 0.1℅+10mA Constant Voltage Mode Range Resolution Accuracy 0~80V 1mV 0.1℅+10mV 0~80V 1mV 0.1℅+10mV 0~200V 2mV 0.1℅+25mV 0~200V 2mV 0.1℅+25mV Constant Resistance Mode LowRange Resolution Accuracy 0.02~2Ω 0.1mΩ 0.5℅+12mΩ @I>4A 0.02~2Ω 0.1mΩ 0.5℅+12mΩ @I>4A 0.0666~6.66Ω 0.1mΩ 0.5℅+40mΩ@I>3A 0.0666~6.66Ω 0.1mΩ 0.5℅+40mΩ@I>3A MiddleRange Resolution Accuracy 2~200Ω 8.6uS*2 0.3℅+1.25mS@V>8V 2~200Ω 8.6uS 0.3℅+1.25mS@V>8V 6.66~666Ω 2.6uS*2 0.3℅+375mS@V>20V 6.6~666Ω 2.6uS*2 0.3℅+375mS@V>20V HighRange Resolution Accuracy 20~2000Ω 0.96uS 0.3℅+0.625mS@V>8V 20~2000Ω 0.96uS 0.3℅+0.625mS@V>8V 66.6~6660Ω 0.29uS 0.3℅+188uS@V>20V 66.6~6660Ω 0.29uS 0.3℅+188uS@V>20V Constant Power Mode Range Resolution @P
