This paperwork describes the development and test of circuitry and software to enable the use of Android mobile phones equipped with Bluetooth to receive the incoming electrocardiogram (ECG) signal from a user and show it in realtime on the cell phone screen. The system comprises three distinct subsystems. The first one is dedicated to condition the analog ECG signal, preparing it for conversion to the digital world. The second one consists of a microcontroller and a Bluetooth module. This unit samples the ECG, serializes the samples and transmits them via the Bluetooth module to the Android cell phone. The third subsystem is the cell phone itself. An application program written to the cell phone receives the ECG samples and suitably charts the ECG signal on the screen for analysis. The good quality of the ECG signal allows for identification of arrhythmias.
This paperwork presents a Pulse Width Modulation (PWM) speed controller for an electric mini-baja-type car. A battery-fed 1-kW three-phase induction motor provides the electric vehicle traction. The open-loop speed control is implemented with an equal voltage/frequency ratio, in order to maintain a constant amount of torque on all velocities. The PWM is implemented by a low-cost 8-bit microcontroller provided with optimized ROM charts for distinct speed value implementations, synchronized transition between different charts and reduced odd harmonics generation. This technique was implemented using a single passenger mini-baja vehicle, and the essays have shown that its application resulted on reduced current consumption, besides eliminating mechanical parts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.