Frequency analysis through speed regulation in direct current motor via open loop in a PID control system. Ciencias de la Ingeniería y Aplicadas, [S. l.], v. 6, n. 1, p. 14–32, 2022. Disponível em: https://investigacion.utc.edu.ec/index.php/ciya/article/view/390. Acesso em: 4 jun. 2026.