A Wireless Li-Fi-Based Signal Generator and Its Use in a Series RC Circuit

• Francisco M. Muñoz-Pérez ^[1] ; Juan C. Castro-Palacio ^[1] ; José Guerra-Carmenate ^[1] ; Miguel E. Iglesias-Martínez ^[1] ; Pedro Fernández de Córdoba ^[1] ; Juan A. Monsoriu ^[1]
  1. [1] Universidad Politécnica de Valencia

     Universidad Politécnica de Valencia

     Valencia, España

     
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 62, Nº. 6, 2024, págs. 426-427
• Idioma: inglés
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• Resumen

  • Typical laboratory experiments in the introductory undergraduate physics course, such as those studying the series RC,1–3 RL,4 and RLC5–9 circuits, use signal generators to generate the input voltage signals and oscilloscopes to perform the voltage measurements. The experiment described here turns a standard function generator into a wireless function generator. This is done by connecting the function generator to an LED lamp, which sends the signal via light to a receptor consisting of a small solar cell connected to the circuit to be powered. We used this Li-Fi-inspired idea to increase the motivation of students for simple circuits.

    As stated in Ref. 10, “LiFi is a new way of connecting to the internet which uses light. It can overcome the spectrum crunch because light has the ability to unleash 1,000 times more bandwidth than radio for carrying data.” Li-Fi uses light beams to send data wirelessly to a remote receptor.10–12 By turning a standard signal generator into a Li-Fi-inspired wireless one, students can get involved with the Li-Fi technology as they gain additional motivation for these laboratory experiments. It can be really surprising and fun for the students to see how the same LED lamp can be used for both illumination of the working area and transmission of information. It is worth pointing out that information is transmitted in this case by intensity-modulated light as the light intensity changes as the voltage at the LED changes.

    A schematic representation of the experimental setup for our proposal of a Li-Fi-based wireless function generator is shown in Fig. 1. It includes a function generator (model Keysight 33210A), an LED lamp (a panel with 24 LEDs, 4.5 V of input voltage), an oscilloscope (model Keysight DSO11052B), and a solar cell (60 mm × 80 mm, 1.5 V of maximum output voltage, 0.65 W, made of polycrystalline silicon).