A mobile battery charger circuit is

A mobile battery charger circuit is a device that can automatically recharge a mobile phone’s battery when the power in it gets low. Nowadays mobile phones have become an integral part of everyone’s life and hence require frequent charging of battery owing to longer duration usage.

Battery chargers come as simple, trickle, timer based, intelligent, universal battery charger-analyzers, fast, pulse, inductive, USB based, solar chargers and motion powered chargers. These battery chargers also vary depending on the applications like mobile phone charger, battery charger for vehicles, electric vehicle batteries chargers and charge stations.

Charging methods are classified into two categories: fast charge method and slow charge method. Fast charge is a system used to recharge a battery in about two hours or less than this, and the slow charge is a system used to recharge a battery throughout the night. Slow charging is advantageous as it does not require any charge detection circuit. Moreover, it is cheap as well. The only drawback of this charging system is that it takes maximum time to recharge a battery.

Auto-Turn off Battery Charger

The aim of this project is to automatically disconnect a battery from the mains when the battery gets fully charged. This system can be used to charge partially discharged cells as well. The circuit is simple and consists of AC-DC converter, relay drivers and charge stations.
Circuit Description
In an AC-DC converter section, the transformer step-downs the available AC supply to 9v AC at 75o mA which is rectified by using a full wave rectifier, and then filtered by the capacitor. The 12v DC charging voltage is provided by the regulator and when the switch S1 is pressed, the charger starts working and the power on LED glows to indicate the charger is ‘on’.

The relay driver section consists of PNP transistors to energize the electromagnetic relay. This relay is connected to the collector of first transistor and it is driven by a second PNP transistor which in turn is driven by the PNP transistor.

In the charging section, regulator IC is biased to give about 7.35V. To adjust the bias voltage, preset VR1 is used. A D6 diode is connected between the output of the IC and a limiting output voltage of the battery up to 6.7V is used for charging the battery.

When the Switch is pushed, it latches relay and starts charging the battery. As the voltage per cell increases beyond 1.3V, the voltage drop starts decreasing at R4. When the voltage falls below 650 mV, then the T3 transistor cuts off and drives to T2 transistor and in turn cuts off transistor T3. As a result, relay RL1 gets de-energized to cut off the charger and red LED1 is turned off.

The charging voltage, depending on the NiCd cell, can be determined with the specifications provided by the manufacturer. The charging voltage is set at 7.35V for four 1.5V cells. Currently 700mAH cells, which can be charged at 70 mA for ten hours, are available in the market. The voltage of the open circuit is about 1.3V.

The shut-off voltage point is determined by charging the four cells fully (at 70 mA for fourteen hours) and adding the diode drop (up to 0.65V) after measuring the voltage and bias LM317 accordingly.

In addition to the above simple circuit, the real time implementation of this circuit based on the solar power projects are discussed below.

Kết quả (Việt) 1:

Một mạch sạc pin điện thoại di động là một thiết bị có thể tự động nạp năng lượng một điện thoại di động pin khi sức mạnh trong nó được thấp. Điện thoại di động ngày nay đã trở thành một phần không thể thiếu của cuộc sống của mọi người và do đó đòi hỏi phải thường xuyên sạc pin do dài hơn thời gian sử dụng.Bộ sạc pin đến như là đơn giản, tia nước, bộ đếm thời gian dựa, thông minh, phổ pin sạc-máy phân tích, nhanh, xung, quy nạp, USB dựa, bộ sạc năng lượng mặt trời và chuyển động cung cấp bộ sạc. Những bộ sạc pin cũng khác nhau tùy thuộc vào các ứng dụng như bộ sạc điện thoại di động, sạc pin cho xe, xe điện pin bộ sạc và phí trạm.Sạc phương pháp được phân loại thành hai loại: phương pháp nhanh chóng phí và chậm phí phương pháp. Nhanh chóng phí là một hệ thống được sử dụng để sạc pin một trong khoảng hai giờ hoặc ít hơn so với điều này, và phí chậm là một hệ thống được sử dụng để sạc pin trong suốt đêm. Sạc chậm là thuận lợi như không cần bất kỳ phí phát hiện mạch. Hơn nữa, nó là giá rẻ như là tốt. Hạn chế duy nhất của hệ thống tính phí này là phải mất thời gian tối đa để sạc pin.Tự động tắt sạc pinMục đích của dự án này là tự động ngắt kết nối một pin từ nguồn khi pin được sạc đầy. Hệ thống này có thể được sử dụng để tính phí một phần discharged tế bào là tốt. Các mạch là đơn giản và bao gồm AC-DC chuyển đổi, chuyển tiếp các trình điều khiển và phí trạm.Circuit DescriptionIn an AC-DC converter section, the transformer step-downs the available AC supply to 9v AC at 75o mA which is rectified by using a full wave rectifier, and then filtered by the capacitor. The 12v DC charging voltage is provided by the regulator and when the switch S1 is pressed, the charger starts working and the power on LED glows to indicate the charger is ‘on’.The relay driver section consists of PNP transistors to energize the electromagnetic relay. This relay is connected to the collector of first transistor and it is driven by a second PNP transistor which in turn is driven by the PNP transistor.In the charging section, regulator IC is biased to give about 7.35V. To adjust the bias voltage, preset VR1 is used. A D6 diode is connected between the output of the IC and a limiting output voltage of the battery up to 6.7V is used for charging the battery.When the Switch is pushed, it latches relay and starts charging the battery. As the voltage per cell increases beyond 1.3V, the voltage drop starts decreasing at R4. When the voltage falls below 650 mV, then the T3 transistor cuts off and drives to T2 transistor and in turn cuts off transistor T3. As a result, relay RL1 gets de-energized to cut off the charger and red LED1 is turned off.The charging voltage, depending on the NiCd cell, can be determined with the specifications provided by the manufacturer. The charging voltage is set at 7.35V for four 1.5V cells. Currently 700mAH cells, which can be charged at 70 mA for ten hours, are available in the market. The voltage of the open circuit is about 1.3V.The shut-off voltage point is determined by charging the four cells fully (at 70 mA for fourteen hours) and adding the diode drop (up to 0.65V) after measuring the voltage and bias LM317 accordingly.In addition to the above simple circuit, the real time implementation of this circuit based on the solar power projects are discussed below.