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.

Features

• Operating Power Supply Dual 15V DC (+/-15V DC)
• Load Current 1Amp, Power Supply Up to 60V DC
• Highly Efficient and Ultra-Precision Current Control
• On-Board Power LED
• Barrier Block Connector for Load connection
• External Or On-Board Trimmer Potentiometer Option for Current Control
• PCB dimensions: 66.52 x 33.66 mm

Connections and other details

• CN1: Pin 1 = +Load, Pin 2 = GND
• CN2: Pin 1 = +15V DC Power Supply, Pin 2 = GND, Pin 3 = +15V Power Supply
• D1: Power LED
• PR1: Optional Trimmer Potentiometer (Do Not Use CN3 Potentiometer If this is used)
• CN3: External Potentiometer Pin 1 = Reference Voltage, Pin 2 = Input, Pin 3 = GND

Schematic

Parts List

Connections

Gerber View

Photos

Video

MAX44251 Datasheet

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