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Mobile Sniffer
This mobile sniffer circuit can detect the use of a GSM mobile in mobile-phone-restricted areas such as examination halls and other ‘do not disturb’ areas. It can detect the activity of the phone from...
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Temperature Control & Indicator System
Here is an easy-to-construct temperature indicator-cum-controller that can be interfaced with a heater’s coil to maintain the ambient room temperature. The temperature control system is based on...
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Make Your Controllers For Any Game Using Arduino: DIY
Nowadays, we have lots of game controllers that are improving the gaming experience over the years. There are number of factors responsible for a game to get a good fan base. Graphics quality, story...
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Door Guard
This door guard uses operational amplifier µA741 and a light-dependent resistor (LDR). Operational amplifier µA741 is used as a sensitive voltage comparator. Preset VR1 provides reference voltage to...
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FM Booster
An antenna amplifier boosts a radio signal considerably for devices that receive radio waves. Many devices have an RF amplifier stage in their circuitry, that amplifies the antenna signal. The received...
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Numeric Water Level Indicator
Most water level indicator for water tanks are based upon the number of LEDs that glow to indicate the corresponding level of water in the container. Here we present a digital version of the...
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PC Based Timer
Timers are very useful both for industrial applications and household appliances. Here is a PC based timer that can be used for controlling the appliances for up to 18 hours. For control, the timer...
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Long Range FM Transmitter
Several circuits for constructing FM transmitter have been published in EFY. The power output of most of these circuits were very low because no power amplifier stages were incorporated. The...
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Smart Emergency Light
An emergency light can come in handy at all sorts of time, especially when there’s a power outage. Now you need not fear dark nights when power breaks down. Here’s a white LED-based smart emergency...
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Automatic School Bell
Consider that a school has a total of eight periods with a lunch break after the fourth period. Each period is 45 minutes long, while the duration of the lunch break is 30 minutes. To ring this...
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Sunset Lamp
LDR-based automatic lights flicker due to the change in light intensity at dawn and dusk. So compact fluorescent lamps (CFLs) are unsuitable in such circuits as flickering may damage the electronic...
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Speed Control of DC Motor Using Pulse-Width Modulation
Pulse-width modulation (PWM) or duty-cycle variation methods are commonly used in speed control of DC motors. The duty cycle is defined as the percentage of digital ‘high’ to digital ‘low’ plus digital...
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Water-level Controller
In most houses, water is first stored in an underground tank (UGT) and from there it is pumped up to the overhead tank (OHT) located on the roof. People generally switch on the pump when their taps go...
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Ethernet Interface for Automation Systems
Communication with remotely located automation systems is possible via the Internet. A physical communication port with a network is required for this communication. An Ethernet interface can be used...
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Periodically On-Off Mosquito Repellent
Some of the mosquito repellent available in the market use a toxic liquid to generate poisonous vapours in order to repel mosquitoes out of the room. Due to the continuous release of poisonous vapours...
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Colour Sensing Robot with MATLAB
A camera is one of the most powerful and accurate sensors if you know how to process the images taken by it for the information you want. You can process subsequent images and extract a variety of...
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Accurate Electronic Stopwatch Project
A stopwatch is invaluable for events and time based competitions. And keeping in with today’s demand, these are available in very fancy designs and options. Presented here is a simple circuit which can...
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RF Signal Detector
This simple RF signal detector circuit can be used to trace the presence of RF signals and electromagnetic noise in your residential area, office or shop. It can be a useful tool while testing or...
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How to Assemble Your Own 3D Printer
3D printing, getting popular for making usable objects, is the reverse of traditional machining where material is removed from a block by drilling, cutting, chiseling, etc for making objects. In 3D...
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Automatic Water Pump Motor Controller
Municipal corporations in many cities supply water during early morning hours. So, you have to wake up early, just to switch on your motor pump and wait till your water tank is filled up. Further,...
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