Fire alarm circuit ABSTRACT Here is a simple fire alarm circuit based on a Light Dependent Resistor (LDR) and lamp pair for sensing the fire. The alarm works by sensing the smoke produced during fire. The circuit produces an audible alarm when the fire breaks out with smoke. When there is no smoke the light from the bulb will be directly falling on the LDR. The LDR resistance will be low and so the voltage across it (below 0.6V). The transistor will be OFF and nothing happens. When there is sufficient
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6 Channel Auto Reverse Sequential Disco Running Lights [pic] From 230 V AC a DC supply of + 5 V is obtained. The power supply is given to the other blocks. The pulse generator at a particular frequency generates the clock pulses. The clock pulses are counted by a counter and gives output after every 10 pulses. The counter drives the transistors‚ which form the triac firing circuit. The transistors fire the triacs and they provide sufficient current to the load. Decorative
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The graph description of the table on the Participation in Selected Leisure Activities of Girls and Boys |Leisure activities |Girls age 5-14 |Boys age 5-14 | |Skateboarding or rollerblading |25 |39 | |Bike riding |58
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These advantages may not be obvious or observed in short period of times. However there are some impacts on the usage of the electronic devices and gadgets games. According to the sources from a survey of Kaiser Family Foundation‚ children are spending an average of more than 7 hours per day on the electronic device which includes television‚ electronic games‚ internet and some mobile devices. These data show that‚ kids today are easily used up more than 50 hours weekly‚ which means the time
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Watching television is an experience shared by most people. It is cheap‚ appealing‚ and within the reach of almost everyone. In this way‚ TV has become an important mass media around the world. Sadly‚ this resource isn’t used in a way that people could get the best possible benefits from it. TV has also become one of the worlds most PREDOMINANT bad habits. The purpose of this essay is to persuade the reader that people shouldn’t watch too much TV because a lot of TV programs are not educational;
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The schematic of an automatic cooler fan for audio amplifiers is given here. The circuit automatically switch ON the cooler fan whenever the temperature of the heat sink exceeds a preset level. This circuit will save a lot of energy because the cooler fan will be OFF when the amplifier is running on low volume. At low volume less heat will be dissipated and it will not trigger the cooler fan ON. The temperature is sensed using an NTC (negative temperature coefficient) thermistor R2. Junction of
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Some parents believe that watching television is bad for their children. So‚ they try to restrict their children from watching TV. However‚ other parents think that there is nothing bad in watching TV. Personally‚ I think that watching TV brings children only benefits unless they spend in front of TV set less then a couple of hours daily. For the following reasons‚ which I will mention bellow‚ I believe that television plays an essential role in child’s development. First of all‚ television helps
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Why are humans so obsessed with screens? Every day people are spending their time playing on their mobile phones‚ watching television and sitting in front of their computer. How larger the screen‚ how bigger the fun‚ phones are getting larger and larger and watching TV is no fun on a small television‚ and why else would you go to the cinema if it’s not because they have an enormous screen? In the first place‚ people want to escape from the reality for a moment‚ so than they can watch a movie
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Global Social TV Market worth $256.44 Billion by 2017 According to a new market research report‚ “Social TV Market: Global Advancements Forecasts & Analysis (2012 – 2017)”‚ the total Social TV market is expected to reach $256.44 billion by 2017 with a CAGR of 11.2%. Browse 62 market tables and in-depth TOC on “Social TV Market: Global Advancements Forecasts & Analysis (2012 – 2017)”. http://www.aarkstore.com/reports/Social-TV-Market-Global-Advancements-Forecasts-Analysis-2012-2017--228908
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circuit ideas Hearing aid IVEDI S.C. DW T.K. Hareendran T his low-cost‚ general-purpose electronic hearing aid works off 3V DC (2x1.5V battery). In this circuit‚ transistor T1 and associated components form the audio signal preamplifier for the acoustic signals picked up by the condenser microphone and converted into corresponding electrical signals. Resistor R5 and capacitor C3 decouple the power supply of the preamplifier stage. Resistor R1 biases the internal circuit of
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