ENGINEERING ARTICLES

Switching techniques of pulse width modulation (PWM) have been popular in the area of power electronics and drive systems. PWM is commonly used in applications like motor speed control, converters audio amplifiers etc. PWM is used to adjust voltage applied to the motor. There is no single PWM method which can suite for all applications. As per the advanced technology in solid state power electronic devices and microprocessors, various pulse-width modulation (PWM) techniques have been developed for different industrial applications. For the above reasons, the PWM techniques have been the subject of intensive research since 1970s. The main objective of the PWM is to control the inverter output voltage and to reduce the harmonic content in the output voltage. The pulse width modulation (PWM) techniques are mainly used for voltage control. These techniques are most efficient and they control the drives of the switching devices. The different PWM techniques are Single pulse width modulatio...

Bluetooth doorbell is an advance doorbell which shows your image to the person standing at another side of this bell. This doorbell is made already! You can buy a wireless doorbell in any hardware store. However, this one you make yourself! Even better, as you get more confident with Arduino, you can modify it to make it uniquely yours. For instance, what if your Arduino triggers a music player instead of a buzzer to let you know that someone has pressed the button. This is very useful devices for home use. Left side of figure 1 shows the doorbell button, and right side of figure 1 shows the buzzer unit that is tucked away on a shelf inside. Figure 1(a) The doorbell awaits visitors! (b) The buzzer unit sits discreetly on a shelf. Parts Required: In this project, one Arduino waits for a button press, while the other one sets off a buzzer when it detects that the button has been pressed.  2 Arduino Unos 2 XBee wireless modules (Adafruit P/N 128) 2 Adafruit XBee bre...

In this mini-project, you’ll create two identical assemblies, each consisting of an Arduino and XBee, along with a button and a LED. When you press the button on one assembly, the LED on the other one lights up, and vice versa. Figure 1: Control LEDs with XBee-equipped Arduinos. Parts Required: You’ll be making two assemblies, so you need two of everything! Arduinos (x2) XBees (x2) Breakout boards (x2) Pushbuttons (x2) Breadboards (x2) LEDs (x2) Jumpers Project Description: Follow these steps to assemble the XBee test platform:  1. Solder the breakout boards: Solder up your XBee breakout boards if you haven’t already. Depending on your kit, this could mean simply soldering in some header pins.  On other kits, however, you must solder in LEDs, capacitors, and so on.  2. Connect the XBees to the breakout boards: Attach the XBees to their respective breakout boards. This typically involves simply plugging in...