TREE

Although electricity is a ubiquitous and there are times when it is not possible at all to connect your equipment to an electrical outlet. The purpose of the KIWI-Powered U-passes is to provide energy to any type of mobile device. You can connect this device to any source of energy, including the car’s cigarette lighter, USB port, an outlet or even solar power through photovoltaic cells leaflets. Once loaded, it has the ability to store this energy for at least 6 months. Finally, in terms of connectors, this Swiss Army knife of the batteries can be connected to virtually any device. From phones, to MP3 players or any other gadget. In terms of capacity, the KIWI U-Powered masi can get loads of 1000 and has the ability to charge 2000mAh. The price was another pleasant surprise is which is less than $ 50 USD.

This cell-phone-controlled audio/video mute switch is highly useful in automobiles. The circuit automatically disconnects power supply to the audio/video system whenever the mobile handset is lifted off the holder for making or receiving a call. You can use any readily available cell-phone holder with some minor alterations or fabricate it yourself as shown in Fig. 1. Fig. 1: Proposed cell-phone holder The circuit is wired around IC LM555 (IC1), the CMOS version of timer NE555, as shown in Fig. 2. IC1 is used as a medium-current line driver with either an inverting or non-inverting output. It can sink (or source) current of up to 50 mA only, so take care while handling it. The audio/video system is connected to the circuit via normally opened (N/O) contacts of the relay. Fig. 2: The circuit of the cell phone-controlled audio/video mute switch When the cell phone is in its holder, LDR1 does not receive any light from white LED1 and its resistance is high. As a result, the voltage at pi...

Charge Your Mobile Phone While Enjoying The Journey Here is an ideal Mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in places where AC power is not available. Most of the Mobile phone batteries are rated at 3.6 V/500 mA. A single pen torch cell can provide 1.5 volts and 1.5 Amps current. So if four pen cells are connected serially, it will form a battery pack with 6 volt and 1.5 Amps current. When power is applied to the circuit through S1, transistor Q1 conducts and Green LED lights. When Q1 conducts Q2 also conducts since its base becomes negative. Charging current flows from the collector of Q1. To reduce the charging voltage to 4.7 volts, Zener diode D2 is used. The output gives 20 mA current for slow charging. If more current is required for fast charging, reduce the value of R4 to 47 ohms so that 80 mA current will be available. Output points are used to connect the charger with the mobile ph...

  Samsung has been showing prototypes of different phones with Tizen and so far is that finally presents the first phone with Tizen, the Samsung Z. Why be so important this phone? The reason is that the operating system Tizen Samsung has been developing for a little while longer and intended to help the company to not depend so much on Android, as it currently does. Additionally, the Samsung Gear 2, Gear 2 and Gear Neo Fit, devices were the first company to have this operating system. The Samsung Z is just a start, then do not expect it to do wonders or win all the awards. The new Samsung phone has a 4.8-inch AMOLED display with 720p resolution, a quad-core 2.3GHz processor (possibly Intel), 2GB of RAM, 16GB of storage with support for micro SD card, an 8 megapixel rear camera, a front 2.1 megapixel camera, a sensor for detecting the heart rate and fingerprint reader. Additionally, the Samsung Z has a 2,600 mAh battery and has dimensions of 138.2 s x 69.8 x 8.5 mm. The first phone ...

Most of the mobile phone complaints are related to the power supply. This is mainly because of improper charging and use of non-recommended chargers and low-quality batteries. Depending upon the make and model, the charging time of mobile phones varies from 1 hour to 3 hours. The charging current is also different for different models. So it is better to use the charger specified by the company only. Equipment for measuring the capacity or the backup time of a battery are not readily available in the market. But by measuring the charging and discharging currents, the approximate backup time of a battery can be found out. For example, charge a battery of 4.8V, 400mA rating for 1 minute and check whether it can discharge for 1 minute through a 400mA torch bulb. If the battery is discharged fully, it would not get charged again through a normal charger. The battery would require an initial charge or  boosting. Here’s a multipurpose circuit (see Fig. 1) for battery boosting as well as ...