What Are Switch-Mode Power Supplies?

Linear power supplies, once quite common, have now been mostly replaced by switch-mode power supplies (SMPS). The liner power supplies typically had a dissipative regulator - a voltage control element - usually a transistor that dissipated power equal to the difference between the unregulated input voltage and the fixed output voltage times the current flowing through it. The dissipative element prevented the linear power supplies from reaching high efficiencies. On the other hand, the switching Read more [...]

What Are Diacs And Triacs Used For?

When you switch on your fan or light, chances are you also have a dimmer controller to control the speed of the fan or the intensity of the incandescent or LED light. Typically, dimmers are useful only where alternating currents are used, because they have components that allow only part of the waveform to reach the appliance. That means the appliance receives only part of the energy supplied and hence runs slower or glows dimly. Dimmers accomplish this AC waveform chopping or phase control with Read more [...]

Give Your Raspberry Pi an Intelligent Power Switch

Whether you use a desktop or a laptop computer, one of its features is the intelligent power supply that shuts down the system once it detects that the software has sent the shutdown command. To switch the system on, you need only press a small button. The Raspberry Pi, or the RBPi, being a low-cost single board computer, does not have this feature. After shutting down the OS, you have to unplug the power cable physically from the RBPi. With large numbers of community projects springing up around Read more [...]

MIPS Creator CI20: Challenge for the Raspberry Pi?

Although the Raspberry Pi or the RBPi did bring a revolution in the world of tiny computers that can teach children the intricacies of computer programming with inexpensive ease, not all are happy about its capabilities. There are two main points of contention with the credit-card sized single board computer – the low amount of RAM and the lack of onboard storage. A quick recap of the RBPi's specifications shows that it uses a system on a chip (Broadcom BCM2835). This includes the 700MHz processor Read more [...]

How do Electronic Potentiometers work?

Nowadays, most electronic gadgets change their settings such as volume, bass, treble, brightness, contrast, sharpness etc., through “up/down” or “+/-” buttons in contrast to the rotary mechanical controls earlier. These are the electronic or digital potentiometers in action. While the principle of operation remains the same whether it is a mechanical or an electronic potentiometer, the functionality of the two is quite different. While the mechanical potentiometer offers a continuous variation Read more [...]

How Do Mechanical Potentiometers Work?

Electronic gadgets of about one generation back (prior to the prolific use of SMD), used rotary mechanical potentiometers for setting different parameters such as volume, tone, brightness, contrast, etc. For adjusting circuit parameters within the gadget, a smaller variation called the trim pot was a common sight. These are outdated now, but those who still own and use these gadgets often wonder how mechanical potentiometers function. The most common example of a mechanical potentiometer is the Read more [...]

Turtle Graphics on the Raspberry Pi

In 1966, Seymour Papert and Wally Feurzig developed the Logo Programming Language. As a part of this, Turtle Graphics was a very simple way of teaching programming to children. It consisted of a robotic turtle starting at coordinates 0, 0 in the X-Y plane on a computer screen. With a command turtle.forward(20), the turtle would move forward by 20 pixels in the direction it was facing, drawing a line as it moved. To turn the turtle where it is standing, a command turtle.right(30) would make it rotate Read more [...]

What’s the difference between SD vs SDHC cards?

We use several types of digital devices, which store data on external memory cards. Unfortunately, just as there is a large variety of digital devices, there is a plethora of memory cards to add to the confusion. People juggle with SDHC, SDXC, SD, MiniSD and MicroSD among the most popular cards. Often it is puzzling to ascertain what type of memory card will suit your camera, phone, MP3 player, tablet or other mobile digital device. Most memory cards are flash type with difference in formats, sizes Read more [...]

Drive a 16-Channel Servo with the Raspberry Pi

To drive servomotors micro-controllers must have PWM outputs. These are output pins on which the micro-controller will generate pulse outputs with controlled or modulated variable widths. Most embedded micro-controller units have one or more of these outputs. The famous single board computer, the tiny credit card sized Raspberry Pi or RBPi also has one IO pin dedicated for PWM. This is the PWM channel available at the GPIO18 of the RBPi and with this, you can drive a single servo at best. However, Read more [...]

What should my CPU temperature be?

Normally, computer users are not very concerned about what temperature their CPU is running at. Desktop users may feel the hot air coming out of the back and laptop users may be concerned if the heat is too much for their laps. In reality, the temperature of the CPU depends on what the computer is doing, that is, how many programs it is currently running and how the manufacturer has arranged the fans in the cabinet. Although the exact information of how hot your CPU should be running will be available Read more [...]