Kit didático para a implementação de filtros passivos e ativos

Abstract

The implementation of filters to remove or mitigate the unwanted signals , improving data acquisition equipment , mainly for telecommunications or instrumentation, has a key role in the electronics industry . In this context , this work presents an educational kit for easy and practical implementation of analog filters , aimed at encouraging students to study analog filters. The kit contains a stand to instance the passives and actives filters’ behavior, a handout with theoretical explanations, a signal generator of sine waves comprised by an Arduino and a DDS module (Digital Direct Synthesis), which will generate a sine input signal applied to the system. In addition, a symmetrical power supply +12 V was created (a current of 1A supporting a maximum), which feeds the operational amplifier used for implementing active filters. The system enables the deployment of passive and active filters. In both cases, can be tested low pass, high-pass , band-pass and band reject filters. The frequency of the input signal will be selected via LCD display that communicates with the Arduino generating along with the DDS module the input signal, in the range from 5 Hz to 2 MHz. For testing an oscilloscope was used and the tests had demonstrated it was possible to implement all the filters mentioned above.