Tag Archives: Guides

How do photovoltaic cells work?

Your calculator probably has a darkish colored panel just above the display. The panel is made up of solar cells that power up your calculator if there is enough light. You may also have seen some solar panels, which people use for charging up their cell phones. Earlier, these solar cells or photovoltaic cells were exclusively used to power the electrical systems of satellites. However, they are now commonly used in less exotic ways as well. How do photovoltaic cells convert light to electricity? Read more [...]

Make the Raspberry Pi Read Analog Inputs

You might have noticed, the Raspberry Pi (RBPi) does not have any inputs for reading analog signals, unlike the PIC, AVR or the Arduino micro-controllers. This is because the RBPi is a digital only computer. Since many sensors generate only analog signals, it would be nice to make the RBPi analog-friendly by giving it some analog inputs. Letting RBPi acquire some analog inputs is easy if you use the MCP3008 chip from Microchip. Since the RBPi does not have a built-in Analog to Digital Converter Read more [...]

Transistors: What Is The Difference Between BJT, FET And MOSFET?

BJTs, FETs and MOSFETs are all active semiconductor devices, also known as transistors. BJT is the acronym for Bipolar Junction Transistor, FET stands for Field Effect Transistor and MOSFET is Metal Oxide Semiconductor Field Effect Transistor. All three have several subtypes, and unlike passive semiconductor devices such as diodes, active semiconductor devices allow a greater degree of control over their functioning. Depending on their subtypes, operating frequency, current, voltage and power Read more [...]

Automate Your Home HVAC System from the Internet Using the Raspberry Pi

The HVAC devices in your home, typically the air-conditioner, thermostats, heating and ventilation, use one or more remote handheld devices working on Infrared (IR) technology. As the HVAC devices are from different manufacturers, you will most likely own a multitude of remote devices, making it difficult to handle and set each of them independently. However, with the Raspberry Pi or RBPi, a small board called the IR Remote Shield and a wireless interface, you can control all the HVAC devices Read more [...]

Digital Isolators vs Optocouplers

Industrial equipment may need to operate in a region of strong electromagnetic fields. There can be a sudden surge in the voltage applied to the equipment, which may be hazardous to the user and the gear. It is crucial that you incorporate a reliable isolation system to take of these issues. Until very recently, the optocoupler was the only practical choice in providing safety isolation for manufacturers of medical and industrial isolated systems. The arrival of digital isolator has however, changed Read more [...]

How to solder – an illustrated guide

We love when we come across electronics info and guides that others are sharing freely - and especially those that encourage others to share their knowledge and work. For example...here is a fully illustrated guide to learning how to solder which was done by the fine folks at http://mightyohm.com. They've created a super guide with all the basics covered as well as some interesting tips and tricks that can make your soldering experience a little better. This would be a great staple for some basic Read more [...]

Demystifying the A/D and D/A Converters

Analog and Digital Signals Analog signals represent a physical parameter in the form of a continuous signal. In contrast, digital signals are discrete time signals formed by digital modulation. Most natural signals, like human voice and other sounds are analog in nature. Traditionally, communication systems were based on analog systems. As demand for systems capable of carrying more information over longer distances kept soaring, the drawbacks of analog communication systems became increasingly Read more [...]

The ins and outs of Peltier Cells

What Are Peltier Cells and How Do They Work? If you join two dissimilar metals by two separate junctions, and maintain the two junctions at different temperatures, a small voltage develops between the two metals. Conversely, if a voltage is applied to the two metals, allowing a current to pass through them in a certain direction, their junctions develop a temperature difference. The former is called the Seebeck effect and the latter is the Peltier effect. Many such dissimilar metal junctions Read more [...]

Parental Control V-Chip – What is it and how does it work?

Parents are concerned over the type of programs their children watch on the television and would like to exercise their control. They do not want their children watching programs with excessive violence or sexual content. Since it is not possible to be always present when the children are watching TV, it is best to have a device automatically detecting the type of program coming through, and blocking it if it is objectionable. All television sets made and sold in the US after 1999 have a special Read more [...]