相关论文: Sub-$10 sound card photogate variants

Photogates are probably the most commonly used electronic instruments to aid experiments in the field of mechanics. Although they are offered by many manufacturers, they can be too expensive to be widely used in all classrooms, in multiple…

Sound cards, which count as standard equipment in today's computers, can be turned into measurement tools, making experimentation very efficient and cheap. The chief difficulties to overcome are the lack of proper hardware interfacing and…

A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of the sound card. A dedicated free…

We have created a simple, portable, low-cost setup allowing the students and teachers to experiment with and discuss electromagnetic induction in a safe way, using low currents. The simplicity and portability make these activities well…

We propose two experiments suited for high school and/or undergraduate physics laboratory which are aimed to the discovery of the practical meaning and usefulness of the FFT analysis as a mathematical and graphical instrument, intended to…

Understanding how sound propagates through different media is fundamental to both science and technology. While sound plays a critical role in natural navigation and underlies a wide range of applications - from medical ultrasound to sonar…

We present an easily reproducible, open-source, sound card based experimental set-up to support transfer function measurement. Our system is able to visualize signals of mechanical and electrical resonances and their spectra in real time.…

Classical and quantum optical communication has gained popularity and momentum in recent years, with growing investment and innovation in quantum technologies. However, the main teaching method in the education of quantum mechanics include…

We present an inexpensive apparatus for measuring the speed of sound, with a time of flight method, using a computer with a stereo sound board. Students measure the speed of sound by timing the delay between the arrivals of a pulse to two…

Lessons and homework problems involving a pendulum are often a big part of introductory physics classes and laboratory courses from high school to undergraduate levels. Although laboratory equipment for pendulum experiments is commercially…

Photoplethysmography is a prevalent, non-invasive heart monitoring method. In this paper an implementation of photoplethysmography on the Raspberry Pi is presented. Two modulation techniques are discussed, which make possible to measure…

We consider the fluctuations of the electrical current (shot noise) in the presence of a voltage time-modulation. For a non-interacting metal, it is known that the derivative of the photo-assisted noise has a staircase behavior. In the…

Experiments in mechanics can often be timed by the sounds they produce. In such cases, digital audio recordings provide a simple way of measuring time intervals with an accuracy comparable to that of photogate timers. We illustrate this…

We report on the construction and characterization of a low-cost Mach-Zehnder optical interferometer in which quadrature signal detection is achieved by means of polarization control. The device incorporates a generic green laser pointer,…

Smartphone is a powerful internet connected computer packed with internal sensors that measure sound, light, acceleration and magnetic field strength. Physics teachers can use them as measurement devices to demonstrate science concepts and…

We present an educational tool, a microscope with a video camera, that can be fabricated either from a standard microscope or assembled from inexpensive, commercially available components (objectives, beam splitters, LEDs, linear stages)…

A simple interfacing project with the 8085-microprocessor kits available in under graduate college labs has been discussed. The interface card to study the I-V characteristics of a p-n diode emphasizes how the microprocessor can be used to…

For physical processes which express themselves as a frequency, for example magnetic field measurements using optically-pumped alkali-vapor magnetometers, the precise extraction of the frequency from the noisy signal is a classical problem.…

We present a schlieren system comprised of 3D printed optical mounts, a sub-$10 mirror, and a smartphone camera. The system is intended to make schlieren imaging accessible to K-through-12 students, educators, as well as hobbyists. In the…

We designed and built a do-it-yourself spectrograph assembly to demonstrate the concept of spectroscopy, an indispensable tool for exploring the cosmos. This spectrograph is designed for optical band (400-750 nm). It uses a transmission…