DC Electronic Load – 1A

This is a very precise Electronic Load project built using the ultra-Precision, Low-Noise OPAMP MAX44251 from Analog Devices. The project can sink current from a power source. It can be used as test gear for power supplies, chargers, solar panels, batteries, and DC-DC converters. The resistor R11 acts as a shunt, OPAMPs convert current into voltage, 2^nd op-amp, and Q1 MOSFET are used to control the load current. A Multi-turn potentiometer helps to adjust the load current in the range of 0 to 1A. The supply voltage is up to 60V DC. The board works with dual supply +/-15V DC and draws a few milli amps. LM317 regulator provides 12V DC top op-amp and LM337 provides regulated -7V supply to op-amp. At full load, MOSFET Q1 produces lots of heat, and a fan and large heatsink on MOSFET will help cool it down. Users may use a current meter in series to load to display the current. Optional onboard Trimmer potentiometer provided in case external potentiometer is not required.