High Gain Yagi Wi-Fi Antenna

Build this wi-fi antenna to build when you want results FAST and have just a few inexpensive tools and supplies available. It will greatly extend your wi-fi range - well beyond the limits of the dipoles that accompany most routers and some wireless adapters. When connected to a USB wireless adapter the performance is excellent. When connected to a high powered wi-fi adapter, the performance is astounding! Forget about building those overly hyped wi-fi cantennas - they don't perform anywhere close to the yagi antennas depicted here.
Sometimes the perfect wi-fi antenna is the one that can be made in an hour's time, from inexpensive parts, and yet enables connections over moderate to long distances. The yagi wi-fi antenna design depicted here is exactly that! It is computer designed, made of wood and wire, and provides high gain and directivity. It is directional - favoring wi-fi signals in one direction and rejecting interference from the sides or behind the antenna. The 15 element wi-fi antenna provides over 15 dB of gain (multiplying your effective radiated power by 31), while the larger 20 element wi-fi antenna provides over 17 dB of gain (multiplying your effective radiated power power by 51). Front to back ratio for both antennas is about 22 dB.
Yagi wi-fi antennas can be rather difficult to make - elements must be precisely cutto the proper length, and spaced at the correct distance from otherelements, or the antenna doesn't work. Before good computer tools were available, a designer used various charts and tables to determine antenna dimensions. These days, however, much of the mind numbing calculation can be carried out in a split second. One excellent tool for crunching design numbers is the yagi antenna modeler, created by Kevin Schmidt (W9CF) and Michael Lee.

Best Transformer less Power Supply Circuit Using IC LR645.

A very interesting yet super simple transformer less power supply circuit has been discussed here. In one of my earlier posts I provided a similar circuit but it utilized a high voltage capacitor for dropping the mains voltage to lower usable levels. Here we study how the mains voltage is controlled to 12 volts and 5 volts using just a single IC LR645G and some other supportive ordinary active semiconductors.

In short the circuit diagram may be understood in the following manner:

• The high voltage AC mains is rectified by the bridge configuration using four diodes at the input.
• The rectified voltage is smoothed by the filter capacitor introduced just after the bridge network.
• The rectified, filtered high voltage is fed to the IC LR645LG, which effectively reduces the voltage to 15 volts at 3 mA.
• The FET pulls the 3 mA current output to 150 mA and feds it to the next stage which incorporates the 5 volt regulator stage.

However one big drawback of eliminating the use of a transformer is the DANGER of high voltage shock that actively hangs with all the naked points of the circuit. Therefore extreme caution must be exercised while building and testing this circuit and other attached circuits.

Parts List

Diodes - 1N4007

Input Capacitor - 4.7uF/400V,

Output Capacitors are 1uF/25V

ICs are LR645LG and 7805,

FET - DN2540N5

Electronics Circuit Application

50 Watt Amplifie small subwoofer Circuits..

This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amp for a small subwoofer.

 

Cell Phone and iPod Battery Charger Circuit..

5 band graphic equalizer Circuits

  

Galaxy S3 Audio Problem and solution..

Samsung Galaxy series is known to be one of the finest smart phone ranges that exist today, and this is mainly because its features have surely beaten a good number of industry giants. But nothing is flawless, no matter how better the technology is, as after some time it is going to start having some issues in it due to any of the reasons.

 

Nokia 6270 PCB board layout.

Nokia 6270 PCB board layout
The front and back side layout of components on Nokia 6270 main PCB board. to be used as mobile phone repair manual on Nokia 6270.