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…

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…

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…

Inrush current at power on or power resumption after a power failure is the major cause of data loss and errors in Microcontroller based electronic circuits. Even the SMPS based power supply is vulnerable, if the inrush current is too heavy. This circuit gives atime delay of 2 minutes to stabilize the power before the…

Just as convenient as an interchangeable long running power source a battery is, it is as important to keep a good care of the battery.  Maintenance of a battery is no longer a tough job as now they are good on their own and doesn’t need frequent user assistance in making the system work.  However,…

Human skin offers resistance to electric current just like a resistor do in  electronic circuits. This transient change in the electrical conductivity of the skin followed by an arousal or oriented response is referred to as Galvanic skin response or GSR. In a fully relaxed person, the skin offers very high resistance and the skin’s…

 You can use this Simple Alarm to protect the door or Window. It gives a loud beep and switch on the room light when an intruder/burglar attempts to breaks the door lock. The alarm functions only after 5 minutes to confuse the intruder.   Working of this burglar alarm circuit is simple. IC1 is used…

 Ultra wide band is a carrier free base band technology used in wireless communications especially in Radar applications. It can provide high data transfer in multi-user network. The technology uses the carrier free band without RF carrier to prevent signal interferences. The technology is highly reliable since it has very high resolution within centimeters. It…

This simple White LED lamp switches on when its surroundings turn dark. It is an ideal portable lamp in picnic sites. It uses solar energy for charging the battery and an LDR for automatic switching.   6 Volt 100 mA solar panel is used to charge the battery during day light. During day time, the…

This capacitor power supply can deliver 12 volt DC and 100 mA current to power low current devices. It is provided with surge protection and is totally isolated from mains supply using two capacitors in the phase and neutral lines. So the connected device is safe even if the phase and neutral lines changes.  …

 Dental curing light is used by the dentists for treating tooth cavity or filling root canal. The therapy involves the targeted action of high intensity light such as UV light to generate heat by concentrating light in the target area. To fill the cavity of tooth, adhesive chemicals such as polymer resin is used which…

Sealed Maintenance Free batteries are widely used where minimal maintenance and space requirements are the main considerations. In UPS systems, it is used because of its maintenance free and eco friendly features. SMF batteries do not require water and acid top up and are totally maintenance free. There is no water loss during the charge-…

Here a simple Vibration sensor to protect door or window. It generates a loud beep when somebody tries to break the door or window. The alarm stops automatically after three minutes. The circuit uses a piezo element as the vibration sensor.   Piezo buzzer exploits the piezoelectric property of the piezo electric crystals. The piezoelectric…

In contrast to the ordinary TV, Digital TV or DTV uses the transmission in Digital format. Digital TV supports various types of picture formats of different combination size and interlacing. The digital format may be High Definition TV (HDTV) or Standard Definition TV (SDTV). HDTV transmission is in p720 (720 Progressive scanning) or i1080 (1080…

 UM 3561 is an excellent Siren generator IC widely used in Toy applications and Surveillance systems to generate different tones. It a ROM (Read Only Memory) IC which can be operated in 2 pen cells and it functions normally down to 2.4 volts. Using only a few components, it is very easy to construct a…

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…

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…

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. 

 Here is a simple but useful battery level indicator to monitor the battery terminal voltage. Efficiency of the battery reflects in its terminal voltage. A good Lead Acid battery will show 13.8 volts in the fully charged state and if it is below 10 volts, the battery needs immediate charging. If the battery voltage goes…

Some Microcontroller based Laboratory instruments such as Digital balance, pH Meter etc have rechargeable battery inside. This inbuilt battery should be properly charged for the error free operation of these instruments. If the instrument is not using (or charging) for long time, its inbuilt battery will be destroyed permanently. This charger timer circuit helps to keep…