TV Tuner card helps to see the Television programs in a Computer or Laptop. TV tuner card is basically a video capture circuit allowing the user to see the TV programs in PC monitor and to record the same in hard disk.TV tuner cards may be the PC1 expansion bus card that can be inserted…

Interactive white board is an interactive display device that displays the computer screen that can be controlled using the electronic pen. It is also known as Smart Board. A projector, projects the computer screen on to the interactive board so that the user can control the PC by touching the surface of the board. It…

 Colour is the visual perception of different wavelengths of light such as red, green etc. Colour derives from the spectrum of visible light which interact with the colour sensitive cells of the retina to give the colour vision. Colour may be defined or quantified based on the degree by which the various colour sensitive cells are stimulated. The science of color is…

 Have you seen Infrared rays so far? It is difficult to see because it is beyond the spectral response of our eye. Our photosensitive cells in the retina detect only the visible light in the range 450-750 nm. But many animals can see infrared spectrum lying above 900nm.Then what we can do to check whether,…

 The Phase Locked Loop or PLL is a feedback system used in high quality stereo decoders, Frequency shift keying, telemetry applications, wide band FM discriminators, frequency multiplication applications etc. PLL integrated circuits are now available to minimize the component count. This note will give the working principle of PLL integrated circuits.   1. Voltage Controlled…

One of the major problems that is to be solved in an electronic circuit design is the production of low voltage DC power supply from AC to power the circuit. [[wysiwyg_imageupload::]]The conventional method is the use of a step-down transformer to reduce the 230 V AC to a desired level of low voltage AC. The most suitable and low cost method is the use of aVoltage Dropping Capacitor in series with the phase line. Selection of the Dropping capacitor and the circuit design requires some technical knowledge and practical experience to get the desired voltage and current.

Surface Mount Technology (SMT) is the soldering of Surface Mount Components (SMC) on the surface of the PCB. The circuit board or device thus created is the Surface Mount Device or SMD. SMT takes great advantage over the conventional Through Hole Technology which is the placing of components through the holes of the PCB. SMT…

While charging gadgets, we often come across those scenarios where the user plugs in the device but forgets to switch the electricity ON. Worse scenario is that where the user doesn’t plug up the gadget properly and leaves it, hoping it to get charged in quick succession of time.   Solving these few and more…

Here is a dual colour lamp to read the code printed on the Transistors and ICs. The code and number printed on the black coloured body of these components are difficult to read if the room light is low since the printing is in faint colour or as impressions. This LED lamp is useful to…

 With a single IC L 7107, you can make a 4 digit voltmeter that can show 0-2000 voltsthrough seven segment display. The circuit is low component one and the reading is reliable and accurate. This circuit is used in digital panel meters to give alpha numerical display. The whole circuit is built around a single 40 pin…

 Here is an Unusual LED indicator for the Battery. It turns on fully when the battery voltage is above 13 volts and starts to blink faintly when the voltage drops below 12 volts .Finally the LED turns off when the voltage drops below 10 volts. Its design is unusual because the LED driver transistor is…

  What is a Router? Router is a Microprocessor controlled device that forwards data packets across the computer network. It is used to connect two or more data lines from different networks. Function of the router is the traffic direction in the network. The most common router is the home router used to transfer small…

Lithium Ion (Li-ion) batteries are common in consumer electronics. It belongs to a family of rechargeable battery and uses lithium as the active material. During discharge, the lithium ions move from the negative electrode to the positive electrode. The flow of lithium ions reverse during charging. Lithium ion batteries are extensively used in portable devices…

Trench MOSFET technology is the newly introduced MOSFET technology in which the gate electrode of the MOSFET is buried in trench etched in Silicon to get a vertical structure to enhance the channel density. The MOSFET using the trench gate is called TrenchMOS or UMOS (since the trench is U shaped).The main feature of TrenchMOS…

Circuit designers are now experimenting with capacitor based power supply due to its low cost and light weight features. Unlike resistive type power supply, heat generation and power loss is negligible in capacitor power supply. But there are many limitations in capacitor power supply. It cannot give much current to drive inductive loads and since…

This circuit can sense the overload condition and breaks the power if the load increases above the set point. It is an ideal circuit to protect Uninterrupted Power Supply devices like Inverter.Let us see its working …The Optocoupler MCT2E and the Resistor R3 (1 Ohm 10 Watts) will do the trick. The Optocoupler has an LED and a Phototransistor inside with connecting leads. The LED of MCT2E is connected parallel to the resistor R3 with a current limiter R2 for the LED. The phototransistor of Optocoupler is connected to the transformer derived 9 volt DC through the current limiter R1. The load is connected through the Common and NC contacts of the relay. So it will work normally at power on. 

 Spy Devices are not for Spying! These devices are meant for surveillancepurpose and for personal use and not for intruding into the privacy of other persons. Spying one’s speech or recording the image of a person without permission is treated as illegal since these can be used for illegal activities. Various kinds of spy devices are now available…

Definitely, Arduino has evolved as a phenomenon in electronics and this Open source prototyping platform has gained immense popularity in the field of electronics. Ever since its introduction in 2005, Arduino has gained much popularity in the electronics world due to its easy to use application properties. It is an extremely easy to use platform…

Set Top Box or STB is the electronic device that helps to see the Television programmes in digital quality. It is a complex embedded system that connects the external source of signals to the television and converts the signals into contents. It has around 30 hardware blocks and a number of software drivers. Modern STBs…

Mobile phone battery requires only two pins for charging, then why there is a third pin? The question is definitely a curiosity generating one. The third pin called BSI pin performs very important functions and act as an interface between the Mobile phone and the Battery. When the battery is removed, without switching off the…