Active Load

An active load is a sophisticated electronic component designed to emulate a dynamic or static electrical load for testing purposes. Unlike passive loads (such as resistors), it uses active semiconductor devices (like MOSFETs or transistors) to precisely control current draw, allowing for simulation of various load conditions including constant current, constant resistance, constant power, or dynamic profiles. In a Gain Stage machine, it serves as a critical test component to verify amplifier performance under different load scenarios.

The active load operates by using a control circuit (often with operational amplifiers) to regulate the current through a power semiconductor based on an input reference signal. It adjusts its impedance dynamically to maintain a specified load condition (e.g., constant current), enabling precise testing of power sources or amplifiers by simulating real-world load variations without physical resistor changes.