Whether you need to flash an LED, energize a relay, turn a buzzer or alarm on or off, or invert a voltage level, the NPN transistor switch can easily solve your problem. This article shows you how to use a transistor as a simple SPST switch.
Some people tend to shy away from using surface mount components in their projects. It seems to be too difficult or needs an array of specialized equipment. In the past, I found myself in this same mindset — wary of using these types of parts. That all changed when...
Listening to shortwave radio is very interesting, and filled with the voices and music of far-off lands. Digging a bit deeper, there is another world of shortwave radio that does not use conventional sounds. It is the realm of data transmissions.
In the US, the DC volt is legally defined by the Josephson array — a super conducting quantum device with a highly repeatable output voltage. Banks of standard cells and temperature-stabilized zener diode references are used by the National Institute of Science and Technology (NIST) to calibrate DC meters for scientific and industrial customers. So how is the AC volt defined?
For quite a while now, we have sought the ultimate add-on interface board to enhance some Raspberry Pi (RasPi for short) projects we want to pursue, including a mobile webcam and a wireless sensor network. For such projects to work, it's essential that our RasPi add-on meet several particular criteria.
As an avid hobbyist, I wanted a convenient way to recharge my battery powered projects without having to tie up the USB ports on my computer. Borrowing from the concept of the wireless chargers on the market, I decided to build my own. So if you like the idea of having a wireless replacement for your USB port, open up your surplus parts drawer and let's start the induction process.
Are you exposed? Build this unit to detect and display levels of radiation, plus you can record months of data to keep track of just how toxic areas may be or become.
Build a solar sequencer that enables a single solar panel to charge multiple batteries of different sizes and capacities, keeping them isolated from each other.
As an experimenter, I use wall warts all the time to power circuit boards, microcontroller boards, and even finished projects. However, during the checkout phase of a new circuit, wall warts present a problem. How do you measure their output when they’re plugged into a board or project box?
Watchdog timers are an excellent way to insure that a microcontroller-based system continues to operate unattended if occasional failures occur. These circuits monitor the operation of the microcontroller and its software and restart it if a problem is detected.
Although there are many variations and implementation techniques, video signals are just a way of transferring visual information from one point to another. The information may be from a VCR, DVD player, broadcast channel, cable television, satellite system, the Internet, or one of many other sources.
Build a Propeller-Based Mentoring Platform for hours of fun with your kids or grandkids making simple computer games or exploring computer-controlled hardware circuits together.
Nothing but circuits. Over 1,000 pages of 'em! All stolen (er... used by permission) from your favorite magazines from the past and present. This thing is like over two inches thick!!
Detailed instructions, helpful diagrams, parts and suppliers lists, and hardware and software tips make building your own equipment even more enjoyable. After all, isn't that what it's all about?