USB Wall Socket. Start Up Project 34

15AI have many devices using USB Port for charging. For this, I purchased one USB Hub to connect 4 devices at a time. But the result was disappointing . The devices are not charging and even a Pen drive is not opening in the Hub. Analyzed the reason and found that the USB port of Laptop is not giving sufficient current to the devices for charging. The USB.2.0 Port can give maximum 200 mA current and USB.3.0 can give maximum 400 mA current. Then how all these 4 devices in the Hub charge normally. The 200 mA current from the Laptop port is sharing to all devices, so no one is charging. Moreover, the Laptop gave a warning that, “USB Port over loaded and shutting down”. Remembered that famous saying “Every problem born with its own solution”. Got the remedy. If the current to the USB Hub is increased, all devices will charge normally. But in that case, Laptop is not useful and I have to make a separate power supply. So made a USB Wall socket. It has an AC socket for charging Laptop, and a 5V, 1 Amps SMPS power supply to power the USB hub. Thus the problem solved. The USB Wall socket is fixed on the wall and powered from Mains. SMPS has well AC-DC isolation, so no shock hazard while charging the USB devices. I found the same type of USB Wall socket in the Online shop but its cost is Rs.2500. I made it at the cost of Rs.250. Let us check it.
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Mini Solar Light. Home Utility Circuit 5

IMAGEYou can make this Solar light using only a few components. You need a 3 V Solar panel, two 1.5 V Rechargeable Pen cells and few other components. It is a miniature Portable Solar light that can be placed anywhere like garden, porch or even in an outing place. During day time battery charges from Solar panel and at Sunset, White LED turns on for around 6 hours.
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USB Light. Simple Design 6


You can make a simple LED light to read and type in Computer or Laptop during night without disturbing other’s sleep. It is also useful as a mini Emergency light in the event of a power failure. It is too simple and powered from the USB port. USB lights are available in the market, but costs around Rs.150. You can make this USB light at the cost of just Rs.5.
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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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QR Code and its uses


This image is familiar to you because it is now printed in the packing of many products including Mobile phone. It is the Quick Response code or QR code used as a Bar code for storing information about the product. It is a “Mobile readable” code that can be used to connect with the website of the manufacturer directly to get the details of the product. Users with a camera phone equipped with the correct reader application (QR Code decoding software) can scan the image of the QR code to display text, contact information or directly connect to the website. This mechanism of linking Physical world objects is called “Hard linking” or “Object hyper linking”.
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How to solve SSL Error

Sometimes when we open Facebook or Gmail, the page will not open and prompts as “SSL Error”. What is this SSL means? It is the “Secure Socket Layer” which is the security system used by browsers especially the Google Chrome for secure login. How this SSL error occurs? SSL works based on the Security certificates authenticated during the browser installation.  The browser works only if the date and time of the computer is up-to-date. Sometimes the date and time may change automatically if the computer is shutdown incorrectly. Switch off  through UPS, Power failure, Battery flat in Laptops etc causes this error. So what will do if the SSL error appears?
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How does the Computer keeps Calendar?

As you know, even if the computer is shut down, it shows the date and time exactly when we boot it again. How this happens, even if the power is completely shut down? The magic is done by the CMOS (Complementary Metal Oxide Semi conductor) circuitry powered by a small 3 volt Lithium CMOS battery.

The computer has three separate clock systems.
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