Experimental physics/science to try in an EE lab? - Page 1
Forum section: electronics / general

author: RoGeorge
author_rank: Super Contributor
timestamp: September 26, 2025, 06:29:52 am
content: Looking for something like the Application Notes for electronic circuits, but on subjects about physics/science experiments. Something that can be made at home, to be fun and interesting at the same time, but a little more advanced than the typical kitchen experiments for kids.Something like a combination between a Physics Journal and an Application Note. Some sort of applied electronics in physics/science, with things to measure, and experiments to conduct in a EE lab, at home.Any suggestions, or books titles I should look for?

author: thephil
author_rank: Regular Contributor
timestamp: September 26, 2025, 07:48:40 am
content: Recreating historical physics experiments is usually fun. E.g. photoelectric effect, speed of light measurements, etc. I even had great fun just measuring the IV curve of a simple lightbulb to see it's PTC characteristic and testing how fast it will limit inrush current when used as a protection device. Not rocket science (anymore) but great entertainment and quite educational.

author: RJSV
author_rank: Super Contributor
timestamp: September 26, 2025, 07:59:24 am
content: Think about this suggestion:It's one of my pet-projects, that hasn't gotten built, yet:Human Retina resembling Pulse Network:This thing also resembles a nuclear reaction demo I've seen.In a big box that demo setup had many many mousetraps, and each would be having a ping-pong ball on the trap top. The enclosing box has a small port opening, for dropping in your 'trigger' and, you could guess the result, as all of the traps start a cascade of triggering and emissions of one ball.That chain-reaction DEMO was interesting, and engaging. (But hazardous)!My idea, for a retina-like chain reaction would require perhaps 200 light sensing components, LDR, not diode. (That's Light Dependant Resistor.). Then, you create small self-,contained circuits, that emit light when triggered, by LDR picking up nearby light pulses.The result is an optical chain reaction, optionally using maybe pulse extension for better visibility.Cadmium sulfate LDR plus maybe a 555 can do the light responsive circuit. That's a lot of 'simple assembly. I'd suggest maybe build as 4 per each little module.It won't be really that close to a real retina, but shaped like an array of 200, which is about 14 by 14 cells, to make the chain reaction demo. Retinas are arrays of light receptive elements.With such large element count, might be best in a classroom, where the array can be prepared, and then used in several DEMO settings.

author: RJSV
author_rank: Super Contributor
timestamp: September 26, 2025, 08:24:03 am
content: Lousy picture, sorry.These toy LED fiber optic finger lights might help produce the kinds of diffuse and not so bright, that would make for an effective DEMO, in the way they would trigger each other,...less prone to overwhelm each other using the tiny fiber optic ends.Sorry I would need to let you sort out the details, but a chain-reaction, having each element with a delay, would have the best chance.Maybe ask the students to tailor the intensity and trigger delays, according to what characteristic the run-away reaction should display !

author: RJSV
author_rank: Super Contributor
timestamp: September 26, 2025, 08:24:43 am
content: Finger lights.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 26, 2025, 10:15:34 am
content: Quote from: thephil on September 26, 2025, 07:48:40 amDid once the light bulb resistance experiment, too.Chart fromhttps://www.eevblog.com/forum/projects/resistance-of-incandescent-light-bulbs/Incandescent light bulbs can limit the maximum current (for another load that is put in series with the light bulb), yet they can do that without a significant voltage drop if the current through the load stays small.Depending on the light bulb model, the inrush current when the filament is cold can easily go an order of magnitude higher than the nominal current (last column in the next table), e.g. 13.71 times higher for a 12V halogen bulb:

author: joeqsmith
author_rank: Super Contributor
timestamp: September 26, 2025, 01:08:37 pm
content: Quote from: RoGeorge on September 26, 2025, 06:29:52 amIt's not much different that those asking for advice on what electronics projects they should build. I enjoy experimenting at home as a hobby, but the field is wide open. I suggest you explore areas that are fun and interesting to you.I have a few college books on Physics. While they are certainly not an experimenters guide to science fair projects, they do offer a lot of basic concepts and work various problems.Beyond my college text books, I have bought books on specific topics that provide more depth. You have the internet and a lot of information is available at your finger tips.Many years ago, I bought an experimenters book on LASERs. Here I was attempting to measure the delay in a fiber optic cable and reference that book.Some of my experiments are much more simple, like heating some water.You may not have any interest heating water and find that too simple. I spent over a year reading about spin and ended up constructing an Electron Paramagnetic Resonance (EPR) spectrometer. This combined my interest in physics, RF and electronics.Most of my time is spent doing research. I tend to learn about a topic, and then try and run an experiment to prove what I have read or help me gain a better understanding of it. Some experiments have a more practical use. For example I constructed a motorcycle simulator that I can use to test changes to software. That project uses the PCI bus, FPGAs, software, controls and a lot of physics... Really, it's all physics!!

author: mawyatt
author_rank: Super Contributor
timestamp: September 26, 2025, 02:04:19 pm
content: Fundamental semiconductor experiments are hard to beat; cheap, simple and "mostly" safe. The simple diode and transistor allows a vast array of fun measurement/experiments, many have been describe here on EEVblog.A few examples, grab a 1N4148 in DO35 glass package, measure the forward and reverse currents at room (26C), cooled (0C) and hot (100C) temperatures. Now use your camera flash and look at the unbiased photoelectric response of the diode on a DSO.Grab a few zener diodes around 4.7, 5, 5.6, 6.2 and 6.8V and repeat the above temperature reversed bias measurements at various reverse bias currents. Study the effects of the breakdown PN junction transitioning between the Zener and Avalanche effects and how they behave wrt temperature and bias.Now grab a 2N3904 and investigate all the fun experiments mentioned here on EEVblog, and the latest described on EDN.https://www.edn.com/unusual-2n3904-transistor-circuit/Add a 2N3906 with the 2N3904 and investigate the various NPNP and PNPN (SCR) junction effects.And so on, lots of fun things to experiment with semiconductors.Best

author: Grandchuck
author_rank: Super Contributor
timestamp: September 26, 2025, 03:07:16 pm
content: Standing wave from a speaker:https://video.search.yahoo.com/search/video;_ylt=AwrJ.YpLq9ZoVgIAS3VXNyoA;_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZAMEc2VjA3Nj?type=E210US105G0&p=use+a+speaker+to+show+standing+waves&fr=mcafee&turl=https%

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 26, 2025, 04:42:35 pm
content: I was going to suggest the "foxhole radio" but I have no idea if it works with modern blades.https://en.wikipedia.org/wiki/Foxhole_radio

author: RJSV
author_rank: Super Contributor
timestamp: September 26, 2025, 05:02:53 pm
content: I was thinking a long the lines of a stand-up box, with three sides, one for the sensors, with optional LED's on 555 pulse extenders, as described above, in the chain reaction demo, plus you could have the second side present a crude array of LEDs.With 14 by 14, the thing does a crude video emulation. Now if it's just for you this wouldn't be that interesting, more for the young ones.14 X 14 needs 196 elements (or cells). The 3-sided box would have a horizontal shelf inside, for the circuit board array. Using flat cable, 14 wires, cleans up the mess of wires, some. Course you would need 14 flat cables, running from the optical sensor face, to the display face.If it's for smaller kids, they could wave a hand or point a flashlight, at the sensors, and observe the display (crude but instantly responsive).A couple kids, stuck in wheelchairs, could play by flashing lights onto the sensor surface.Very relevant to modern computer imaging, and introduces concept of arrays...even math arrays !

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2025, 12:36:37 am
content: Measuring the speed of sound with a sine wave into a speaker, and a microphone or two microphones and an oscilloscope would be fun.I think the most "scientific" experiment I ever did was measuring noise with a sampling voltmeter, stopwatch, and calculator, but it would be difficult for most to appreciate.

author: Smokey
author_rank: Super Contributor
timestamp: September 27, 2025, 01:55:17 am
content: https://www.youtube.com/@TheSignalPathShahriar often does a physical lab experiment to show off the capabilities of various equipment he is working on or reviewing. He's pretty active here.https://www.eevblog.com/forum/profile/?u=8240

author: Bud
author_rank: Super Contributor
timestamp: September 27, 2025, 02:13:21 am
content: Radar and Doppler effect demo using an inexpensive radar module from Ali.

author: jonovid
author_rank: Super Contributor
timestamp: September 27, 2025, 02:45:01 am
content: experiments with electromagnetic sniffing of appliances in and around the lab.electromagnetic emissions may reveal previously unknown microcontroller activities

author: TimFox
author_rank: Super Contributor
timestamp: September 27, 2025, 02:54:45 am
content: TheScientific Americanmagazine used to run a monthly article about projects for amateur scientists.One of the book collections from that series: C L StongThe Scientific American Book of Projects for the Amateur Scientist, Simon & Schuster 1987 (paper)The earliest one in the series was published in 1901.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 27, 2025, 08:19:02 am
content: Quote from: TimFox on September 27, 2025, 02:54:45 amBrowsing it as we speak:https://www.sciencemadness.org/library/books/projects_for_the_amateur_scientist.pdfSeems to be the kind of tinkering books I was looking for, thank you!

author: mawyatt
author_rank: Super Contributor
timestamp: September 27, 2025, 12:41:30 pm
content: Quote from: jonovid on September 27, 2025, 02:45:01 amConsiderable effort has gone into"remote sniffing"and in the prevention of suchBest

author: Canis Dirus Leidy
author_rank: Regular Contributor
timestamp: October 01, 2025, 12:45:00 pm
content: Quote from: RoGeorge on September 26, 2025, 06:29:52 amDo you read Russian?Seriously, though, it's worth looking at the teaching materials for school physics teachers. They should contain descriptions of demonstration experiments similar to those shown in the pictures (left: demonstration of corona discharge; right: principle of operation of an electrostatic filter).UPD:Another old book(in Russian, of course) with demonstration experiments on electricity, ranging from hydraulic and mechanical models of electrical circuits to diffraction and interference of microwave (10GHz) radiation.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 01, 2025, 01:42:18 pm
content: No, only barely know the alphabet, learned it by identifying Russian ICs.Fortunately, the experiment drawings give away the topic.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: October 01, 2025, 07:53:13 pm
content: I am old enough to remember when the word 'Physic' was used to relieve constipation. When I was a wee lad, me MUM used to boil prunes and made me drink the resulting juice,which was called a physic.

author: TimFox
author_rank: Super Contributor
timestamp: October 01, 2025, 09:14:16 pm
content: Long before your time: in the Prologue to Chaucer's Canterbury Tales, referring to "With us ther was a DOCTOUR OF PHISYK, In al this world ne was ther noon him lyk To speke of phisik and of surgerye;""For gold in phisik is a cordial, Therfore he lovede gold in special."That is why I referred to myself professionally as a natural philosopher.

author: dustooff
author_rank: Contributor
timestamp: October 05, 2025, 12:58:58 pm
content: Experiments involving light using: prisms, diffraction grating, single slit filter, coherent light sources, polarizing.good for giving the 'aha moment'Also scientific photography using film cameras, macro, bellows, offset lens.Different techniques were possible using b/w film vs colour.I still remember as a kid being amazed by a pinhole camera.