Desenvolvimento de protótipo de ponteira de corrente de baixo custo para osciloscópio para aplicações didáticas

Abstract

This paper presents the development of a low-cost current probe prototype designed for waveform visualization on an oscilloscope, capable of measuring both direct current and alternating current. The main purpose of the probe is its use in educational applications. The project employs an analog-output Hall-effect sensor to detect the magnetic field proportional to the measured current, mounted in a movable clamp arrangement that enables non-invasive current measurement without breaking the circuit under test. Signal conditioning is performed using an operational amplifier in inverting configuration, together with passive RC filters. After assembling the functional prototype, comparative tests were carried out against an equivalent commercial current probe. The prototype proved capable of operating reliably with DC and AC currents (sinusoidal and square waveforms) up to 5 kHz and 3 A peak. The total cost of the developed prototype was slightly above 10 % of the price of the reference commercial equipment, while delivering trustworthy results within the specified operating range.