Hacked LED Flood Light. Start Up Project 19


16AOnce I purchased a 10 watts LED Flood light for Rs. 450. The Ad was so attractive that it is capable of giving light similar to 40 watts Tube light with low current consumption. But the result was disappointing. So hacked it to see the power, current and voltage consumption. It is a 12Volt 10 Watts LED Flood light as mentioned in the pack. The result was very interesting. Nothing matches with theory, specification and real measurements. Generally, the 10 Watt White LED works on 12 V DC and requires 500 mA to 1 Amps current to get full brightness and Flood light effect. It has around 10V Forward voltage. It is usually powered by a high current LED driver that delivers 500 mA to 1 Amps current. Here comes the reality. Many LED flood lights use low current LED drivers or Capacitor power supply. LED Driver is a small SMPS with an output current rating. It must match with the current requirement of the LED. Cheap Capacitor power supply can give only 75 mA current per uF. So we purchase the lights by looking the specifications on the package and not realizing the actual condition of the light. To experiment with that Flood light, opened it to see what is happening inside.Secret revealed.
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Solar Day Light. Start Up Project 15


1Why use lights during day time to waste electricity? Sometimes we need it in some rooms. We can go for a “Green Solution” to harvest Solar energy for lighting an LED light during day time. Just fix a small Solar panel and a Strip LED. It needs no battery  because the solar panel itself acts as a battery. It generates DC voltage when the Photons of the Sunlight energize its semiconductor. So the light remains on throughout day time. You need only a 12V Solar panel and a Strip LED. Connect and relax. It will do its work for 20 years. No circuit is in it and you can easily connect it.
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Free Energy from Computer Fan. Start Up Project 11


6AIt is not a wonder but a real fact that, we can light a 3 V 1 Watt LED without any battery power. You can harvest that much “Free Energy” from a Computer cooling Fan that is resting in the Junk box. A Computer Fan generates around 1.5 Volts with a current of around 80 mA during its full speed rotation when coming close to a Table Fan. By adding a Joule Thief circuit, we can boost this 1.5V to around 4 volts. Well, that is a good idea. When the Computer Fan is close to a Table fan, the forcing wind from the Table Fan starts to rotate the Computer fan in its full speed. The 1.5V thus generating from the Computer fan appears in its connecting wires. Joule Thief takes this voltage and boosts it to 4V. It is sufficient to light a 3 V 1 Watt LED. The Computer Fan used in the project is an original one without any manipulation and not like the one found in some videos with a hidden battery. Let us see the “Free Energy Magic”. You can also name it as “Wind Power Project”.
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Mini FM Station for Home. Starter Project 7


9AThis Tiny FM Station can transmit the Songs from an MP3 Player though out the home. Its range is around 100 Meters and operates in the 87.5 MHz frequency. The songs can be heard in a Mobile Phone, FM Radio, Music system etc placed in any room. The unique feature of the FM Transmitter is that it has no Trimmer capacitor . Instead a fixed capacitor is added with the coil to form the Tank circuit. So there is no need for tuning the FM Transmitter. The FM radio will pick its frequency during scanning.
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Charger for 3.6V Battery. Home Utility Circuit 1




3.6V-BATTERYNow a day’s many LED Torches and Emergency lights are using in Home which are powered by 3.6 Volt rechargeable battery. Due to improper charging, battery will damage and the torch becomes useless. In many of the makes, a Transformerless power supply is used to charge the battery but it may easily fail due to voltage spikes in the mains line. So here is a simple battery charger for all kinds gadgets using 3.6 V battery.
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ATmega328 Microcontroller. Design note 9


ATmeg328-Microcontroller.ATmega 328 is the single chip Microcontroller from Atmel and belongs to the mega AVR series. Atmel corporation is an American based designer and manufacturer of semiconductors founded in 1984. ATmega328 is now widely used in many projects where low cost microcontroller is needed. The most common implementation of ATmega328 is on the Arduino development platform namely Arduino Uno and Arduino Nano boards. A low power alternative of ATmega328 called ATmega328P is also used now which is a pico power version.

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Mobile Bug- Page updated


mobile-bug1

This is one of my most attracted circuit published in Electronics For You years back. But still it is in limelight .More than 200 students selected the circuit as their engineering project. It detects an active mobile phone even in the silent mode and beeps. It’s range is 2 meters radius. It is ideal to monitor Mobile phone restricted areas like Examination hall and Confidential rooms. It detects, Incoming and Outgoing calls, SMS, MMS, Video capturing, Photo capturing etc. I have slightly modified the circuit to increase its range. Check this updated page to get full details including the project report and video of the circuit.

https://dmohankumar.wordpress.com/most-used-circuits/