A Dummy Load for Testing and Measuring Amplifiers

Abstract

This thesis went through the process of designing a versatile resistive load used when testing amplifiers at Darkglass Electronics Oy. The device was intended for internal use in the company in the process of product development and quality assurance. The device that was designed in this thesis was intended to replaced the dummy loads used earlier to improve user safety and ease of use.

The design process of the device's impedance selection system, the instrumentation amplifier needed for separating ground potentials and the PCB design phase were explained in this document. The PCB was designed using Altium Designer software.

Before building the final device the design is simulated and the functionality and different design aspects are analyzed according to the results of the simulations. The circuit was designed and simulated by using LTspice software.

Finally the performance of the device is evaluated by measuring signals going in and coming out and by analyzing them against the expectations.

This thesis will also give a quick look at some of the phases that go into a research and development project in the electronics industry. As an outcome of the thesis a device was created to be used in future product development processes to analyze the functionality and performance of new products.