I just posted on www.diyPhysics.com about my 10 MHz rubidium standard based on a surplus Efratom M-100. It is a free-standing 10 MHz +/-5×10-11 frequency standard for frequency counters, as well as a precise calibration source. I use it to keep precise track of frequency when working on Earth-Moon-Earth (EME) communications, where even tiny errors in tuning can make the difference between success and failure to receive weak echoes. Read more…
SharkVision – A Sensing Suit for the Blind
Hannah Prutchi, 8th Grade, Science, VMS, October 2011
Blind people often use canes to avoid obstacles when walking. But, these are intrusive, can only detect obstacles where they are pointed, and could be dangerous to other people. I devised the “SharkVision Suit” to help blind people move around their environment more easily.
I developed this idea from the concept that sharks find their prey by sensing disturbances in an electrical field they form around their bodies. This suit simulates the shark’s ability to sense objects around its body, giving a blind person a new type of sense. Read more…
Posted to www.diyPhysics.com:d.i.y. 250 kV High Voltage DC Power Supply with Neat Trick for Switching Polarity
I just posted at www.diyPhysics.com detailed instructions on the construction of a 250 kV DC high-voltage power supply. Although my hack for switching the polarity (referenced to ground) is simple, I am very surprised that I’ve never seen it elsewhere!
In my prior post I told about components in my CO2 laser’s RF power supply becoming unsoldered when they overheated. After the repair, I needed some way of retuning the RF output stage for maximum laser output. This motivated me to build the power sensor shown in the picture above. Read more…
I was thinking about buying a laser engraver/cutter for home, but after retrofitting for CNC the Micro-Mark mini mill that my wife gave me for my birthday, I figured that I could simply add a CO2 laser to the X2 mini mill.
Before describing the mod, I figured you would want to see some results. Here is a YouTube video of my X2 mini-mill laser engraver in action: Read more…
Home-Made Radiac Turns Surplus Military Scintillation Probes into Sensitive, General-Purpose Gamma Radiation Counter
Military-surplus scintillation probes meant for the detection of plutonium contamination are widely available in the surplus market. The DT590A/PDR-56F “Plutonium-239 Contamination X-Ray Probe” was used with the PDR-56 Radiac Set (radiation detection and measurement instrument), that has been obsoleted by the US Air Force.
The probe is designed specifically for detecting the 14 to 21 keV gamma lines emitted by Plutonium-239 along with its main alpha-particle emissions. For this reason, despite its availability in the surplus market, this probe has not found wide acceptance by science enthusiasts interested in radiation counters.
I just posted to www.diyPhysics.com detailed instructions for the construction of my home-built PDR-56-like radiac set capable of driving a surplus DT590A/PDR-56F “Plutonium-239 Contamination X-Ray Probe.” In addition, I also give instructions on how to open the single-channel analyzer window to convert the instrument into a very sensitive, general-purpose gamma radiation counter. Read more…
Some time ago I was developing a medical instrument which required histogramming, which got me in the mood to retake my own PIC MCA project(http://home.comcast.net/~prutchi/index_files/scint.htm ). I used the variable RAM in the microcontroller (16F877), so I limited the number of channels to 95 and let the histogram run until some channel reaches 240 counts (the highest 8-bit number that yields an integer when divided by 8). The firmware then displays the spectrum as a bar with a maximum height of 30 pixels for each one of the 95 channels.
Click here for complete how-to construction instructions in pdf format.
Click here for a pdf of the schematic diagram for the front-end of the MCA
Today we received the first two copies of our new book! It is a do-it-yourself book on Experimental Quantum Physics, and was published by John Wiley & Sons.
From the back cover:
“Build an intuitive understanding of the principles behind quantum mechanics through practical construction and replication of original experiments.
With easy-to-acquire, low-cost materials and basic knowledge of algebra and trigonometry, Exploring Quantum Physics through Hands-on Projects takes readers step by step through the process of re-creating scientific experiments that played an essential role in the creation and development of quantum mechanics.
Presented in near chronological order—from discoveries of the early twentieth century to new material on entanglement—this book includes question- and experiment-filled chapters on:
- Light as a Wave
- Light as Particles
- Atoms and Radioactivity
- The Principle of Quantum Physics
- Wave/Particle Duality
- The Uncertainty Principle
- Schrödinger (and his Zombie Cat)
From simple measurements of Planck’s constant to testing violations of Bell’s inequalities using entangled photons, Exploring Quantum Physics through Hands-on Projects not only immerses readers in the process of quantum mechanics, it gives them insight into the history of the field—how the theories and discoveries apply to our world not only today . . . but also tomorrow.
By immersing readers in groundbreaking experiments that can be performed at home, school, or in the lab, this first-ever, hands-on book successfully demystifies the world of quantum physics for all who seek to explore it—from science enthusiasts and undergrad physics students to practicing physicists and engineers.”
For more information, please visit our d.i.y. Modern/Quantum Physics projects website at: www.diyPhysics.com