In this article I will talk about how I made a tool for photomicrography from an old digital camera and CD-ROM lens.
I plan to create a quadrocopter as a platform for a flying robot for a very long time. I did my first calculations and ordered the parts a year ago. However, to create a copter just to fly, operating it with a remote control or even in FPV mode is not my ultimate goal. Therefore the copter should be as flexible as possible and less expensive.
All required parts for the copter are available, but to build the copter is a simple thing only in theory. It requires variety of skills, such as a programming, engineering and so on. Therefore, the process moves pretty slowly, but I want to fly :) Lack of visible results demotivates, especially when progress is there, but not obvious. Also, to experiment on a large quadrocopter is expensive and dangerous.
So I decided to build a minicopter for my experiments. As always, the task is to make it cheap and simple.
My result is finished copter for 1 day just for $ 120 dollars (including shipping and the quadrocopter costs), and with additional hardware it comes to $ 145 dollars.
The vast majority of us have been using a very useful device as an uninterruptible power supply (UPS). The power supply quality is not always perfect, so sometimes the tiniest power problems could be expensive. Data loss is always unpleasant, and sometimes it is fatal. So the device is purchased, placed under the desk, and plugged in. Its owner is sure that in any case, when a power failure occurs he will have time to complete his work correctly, and maybe make a backup on a flash drive. As time passes, and UPS has been guarding a computer like a real guard dog. The owner is calm and everything is very well. But one day the power outage did occur, and the UPS immediately switches to the battery backup, this time the power outage will stay for some time. We easily copy the files (after all we have no less than 15 minutes for a backup), and then the UPS starts beeping quite often and shuts down. How come the UPS did not protect us from that situation? It just inspired in us false confidence in our security! Why did it happen?
The thing is in the batteries that power our hardware when the power supply is turned off. But the batteries are not eternal, they degrade, their capacity and the battery life are reduced as well. Unfortunately, this process often is not controlled by anyone, the owner is confident that the computer is protected, but this time the battery is discharged, it is just a dummy.
In this article I would like to tell a story about the English steam engine, and how it became a small electric generator in a regular apartment.
Right from the beginning of the steam expansion in the XIX century, the different types of engines were built, including small and decorative engines. When the steam engine was a novelty, those models had been shown to the amazed audience, and when it became widespread, the steam engines turned into an excellent tutorial and a wonderful toy for the younger generation of creators of the Industrial Revolution. So, at the end of Victorian era and at the beginning of Edwardian era the companies began making toy steam engines. In the XX century, namely in 1937, when the steam machineries lost their popularity, in the United Kingdom appeared Mamod firm, the name means Malins Models. Since then this firm has been providing the steam engines for everybody. So in the 60s, they have supplied with the engine an unknown person who sold this engine to another person that put up for sale this unit on eBay. The engine is worn out. After winning the auction I paid for this unit and got it by the Russian Post. In my hands I was holding a box with Royal Mail stamps and the inscription “Steam engine”.
In this article you will find out why the photographic studios do not use the fluorescent lighting, as well why LEDs have not taken over the world yet, and has it been worth to use them for street lighting. Let's go!
Color and spectrum
We all know that our eyesight is primitive and ternary: we have three types of color receptors, such as red, blue and green.
However, the life is more complicated as usual, and the color is determined by the length of wave / energy of a light quantum. Accordingly, we get into our eyes a light quantum in the middle between red and green, and these types of receptors will react to it in half of force. From here comes the various strange mixing of colors, and if the object reflects both red and green light, we will see the yellow, although in fact there is not any light quantum with yellow length of wave.
You all like lasers. I know I like them too. If someone does not like them, he probably did not see the dance of sparkling dust or a laser light show.
In this article I will discuss the lasers and how to use them, but first I will talk about the laser safety and danger.
Why is a laser dangerous?
A laser is "concentrated light" in that its light of pretty much one frequency and focused in a tight beam. And if this light is directed into someone's eyes, damage to the retina can result. In higher power lasers, we find applications where they can inscribe diamonds or cut all kinds of things, including metal. If a laser beam can cut through a thick metal plate, it can cut through flesh with ease. A laser this powerful could take off a limb. Directed at the eye, it would destroy the eye in an instant. Spaces where lasers are being used require that warning signs will be posted and that individuals working there wear appropriate eye protection. Divergence from safety procedures can result in serious injury. So be very careful with lasers!
Every day the websites post some good reviews of new and interesting gadgets, where all device features are usually described perfectly well, but the gadget's photos are not that good. Often, we see this:
I have a Toyota Corolla 2003 with the factory built-in a car cassette radio. Of course, I have never used the cassettes, but a radio and fm modulator came in handy for me.
I am not particularly a music lover, but I wanted something more. Here are options what I had:
1. Put the frame for 1 or 2 din and install the ordinary cassette radio.
2. Buy its native one for $ 70 dollars on eBay with the CDs, but without the MP3 :)
3. Buy a fancy one for $ 600 dollars that would fit to my car.
However, I did not like any of the above…
1. An ordinary cassette radio did not have any computer.
2. Trade bad for worse :).
3. It is too expensive and not very popular ...
There came an idea to install the computer in the car. Here is what it was before and after.
I have always been interested in a subject of electric transport. When I finally moved from theory to practice, the long-awaited moment came. I would like to share my experience below.
Here are a couple of thoughts as an introduction.
Why now is everybody talking about electric cars, electric airplanes and electric bikes so actively? Finally, the main problem of electric transport was almost resolved, because there began appearing the quite compact and high-capacity batteries. Moreover, they are being charged for the acceptable time. In fact, just this was waited, and all the rest as a car body, chassis, electronics and electric motors were created a long time ago. All of this has already being used for a hundred years. The electric motors allow using the new solutions; for example, to be installed in the hubs of wheels.
Let us get to the point!
- ordinary bike, the price is about $ 200
- electric motor: 48V / 380W
- battery: 48V / 10A
- speed without pedaling on a flat road 35-40 km / h
- traveling distance: 22-25 km on the hilly country and the city
- total charging time: 2 hours
On the way
I used to turn off all appliances when I was leaving for a few days. However, very often I want to know if everything is all right at home: Was not it burned down? Did not it collapse? Was not it robbed? Alas, I could not find on the market a fully autonomous device that is capable to monitor the premises and send photos to the owner. I had to make a gadget by my own hands.
I did not have any experience with microelectronics, so first I had to learn the basics of this science. I was pleased by the idea that I will build a unique device, which no one has not done yet. What I built after five months of work, I would like to offer you today.