TREE

Looking for an efficient USB charger that can operate from a 12V car battery? This unit functions at up to 89% efficiency and can charge USB devices at currents up to 525mA. Best of all, it won’t flatten the battery if it's left permanently connected, as long as you remember to unplug the USB device. There are lots of USB chargers on the market but this device has two stand-out features: high efficiency and low standby current. In fact, its standby current is just 160µA, a figure that’s well below the self-discharge current of most lead-acid batteries. This means that you can leave the device permanently connected and it will not cause that battery to go flat (or at least, not much faster than it would of its own accord). Picture of the project: Why is this useful? Well, in September 2009’s “Ask SILICON CHIP” section, D. E. of Ainslie, ACT asked if it was possible to connect a 12V-to-5V USB charger directly to the battery on a motorbike. His reason for wanting to do this is that ...

This is a circuit solar charger via USB cable emergency , it is an alternative circuit that uses solar cell and LM317 to regulate and make a recharge via USB for electronic equipment that can be IPODs , cell phones, MP3 , tablets , etc. .   The simplicity of the circuit can be noted that he does not have much appeal, but it's enough to make a simple battery charge . The Solar Cell should be 12v current should be enough for loading , 10 % of the batteries .   Battery Charger Circuit using Solar Cell Circuit Diagram

This battery charger circuit is regulated and adjustable to make this circuit able to charge the mosto NiCAD battery. This adjustable regulated battery charger circuit will work for single cell or multi battery cell which connected with series/parallel connection. The maximum voltage of the batteries should be 18V maximum. Power transistors Q1 and Q2 are connected as series regulators to control the battery charger ‘s output voltage and charge-current rate. An LM-317 adjustable voltage regulator supplies the drive signal to the bases of power transistor Q1 and Q2. Potensiometer R9 sets the output-voltage level. A current sampling resistor, R8 (a 0.1 ohm/5W unit), is connected between the negative output lead and circuit ground. For each amp of charging current that flows through R8, a 100mV output is developed across it. The voltage developed across R8 is fed to one input of comparator U3. The other input of the comparator is connected to variable resistor R10. As the charging volta...

Today, the spread of rechargeable batteries, chargers and circuits that are required for them has led to the spread. Ni-Cd batteries, cell phones, battery-powered drills posal is widely used in many electronic devices and circuit.  Ni-Cd Battery Charger Circuit Diagram These types of circuits are used to charge the batteries, under constant tension, provide stable current level circuits should be pretty good. The output voltage can be set for this purpose, a charging circuit is made ​​with LM317 IC regulated. Improved standard LM317'li circuit connection, the figure was obtained charging circuit. Current limiting circuit formed by transistors, resulting high current output off, which makes the task of protecting the circuit and the batteries. Circuit, 5 Ah (Ampere-hours) of current to the battery can provide 1A'lik. LM317 integrated circuit connected to the refrigerant heating must be avoided. Output connected batteries, charging circuit output voltage value in accordance with ...

This circuit delivers an initial voltage of 2.5V per cell to rapidly charge a car battery. The charging current decreases as the battery charges and when the current drops to 180 mA the charging circuit reduces the output voltage to 2.35 V per cell, leaving the battery in a fully charged state. This lower voltage prevents the battery from overcharching, which will shorten its life. The LM301A compares the voltage drop across R1 with a 18 mV reference set by R2. The comparator’s output controls the voltage regulator, and produce the lower float voltage when the battery-charging current, passing through R1, drops bellow 180 mA. Temperature compensation helps prevent overcharging, the LM334 temperature sensor should be placed near or on the battery. Because batteries need more compensation at lower temperatures, change R5 to 30Ω for a tc of -5mV/0C per cell il this circuit will be used at temperatures below – 200C. The charger’s input voltage must be filtered dc that is at least 3V higher...

This  Battery Charger Electronic circuit Project   An LM317 voltage regulator is configured as a constant-current source. It is used to supply the 50 mA charging current to S01-S06, an array of AA-cell battery holders. Each of the battery holders is wired in series with an LED and its associated shunt resistor. Battery charger using LM317 Circuit Diagram: When the battery holder contains a battery, the LED glows during charging. Each battery holder/LED combination is paralleled by a 5.1-volt Zener diode. If the battery holder is empty, the Zener conducts the current around the holder. A timing circuit prevents overcharging. When power is applied to the circuit, timing is initiated by IC2, a CD4541 oscillator/programmable timer. The output of IC2 is fed to Ql. When that output is high, the transistor is on, and the charging circuit is completed. When the output is low, the transistor is off, and the path to ground is interrupted. 

Circuit Diagram:  Description Here is the circuit diagram of IC Controlled Emergancy Light With Charger or simply 12V to 220V AC inverter circuit. The circuit shown here is that of the IC controlled emergency light. Its main features are: automatic switching-on of the light on mains failure and battery charger with over-charge protection. When mains is absent, relay RL2 is in de-energized state, feeding battery supply to inverter section via its N/C contacts and switch S1. The inverter section comprises IC2 (NE555) which is used in stable mode to produce sharp pulses at the rate of 50 Hz for driving the MOSFETs. The output of IC2 is fed to gate of MOSFET (Q4) directly while it is applied to MOSFET (Q3) gate after inversion by transistor Q2. Thus the power amplifier built around MOSFETs Q3 and Q4 functions in push-pull mode. The output across secondary of transformer T2 can easily drive a 230-volt, 20-watt fluorescent tube. In case light is not required to be on during mains failure...

Simple Solar charger circuit to take advantage of sunlight shining on the earth can continue to be utilized to serve as a power source so that we can at least save on electricity prices continuing to rise, below is one of a series of simple power plant can be created and used to fill your motorcycle battery or for emergency lights . The circuit scheme of Solar Power Generation Sunlight is received by the solar panels are then processed into electricity, but electricity generated from each panel is still too small where the 8 Cell Panel arranged in series only mrnghasilkan voltage of approximately 4 volts with a current 200 mA. nah therefore required an electronic circuit to increase the voltage and current enough to be used as a Battery Charger . Electronic Rainmaking act as a series of DC to DC Inverter (DC to DC Inverter), which was built by two pieces of Capacitor, Resistor 1, a transistor , a diode, and a coil which is the point of the creation of this series. The circuit ...

Except for use as a normal Battery Charger , this circuit is perfect to 'constant-charge' a 12-Volt Lead-Acid Battery , like the one in your flight box, and keep it in optimum charged condition. This circuit is not recommended for GEL-TYPE batteries since it draws to much current. The above circuit is a precision voltage source, and contains a temperature sensor with a negative temperature coλficient. Meaning, whenever the surrounding or battery temperature increases the voltage will automatically decrease. Temperature coλficient for this circuit is -8mV per °Celcius. A normal transistor (Q1) is used as a temperature sensor. This Battery Charger is centered around the LM350 integrated, 3-amp, adjustable stabilizer IC. Output voltage can be adjusted with P1 between 13.5 and 14.5 volt. Lead Acid Battery Charger Circuit Diagram T2 was added to prevent battery discharge via R1 if no power present. P1 can adjust the output voltage between 13.5 and 14.5 volts. R4's value can be...

The design of the charger is similar to that of many commercially available chargers. The charger consists of a mains adaptor, two resistors and a light emitting diode (LED). In practical use, this kind of charger is perfectly all right. Resistor R1 serves two functions: it establishes the correct charging current and it drops sufficient voltage to light the diode. This means that the LED lights only when a charging cur-rent flows into the battery. The charging current is about 1/4 of the battery capacity, which allows a slight overcharging, and yet the charging cycle is not too long (4–5 hours). Circuit diagram : NiCd Battery Charger Circuit Diagram The value of the resistors may be calculated as follows, for which the nominal e.m.f. and the capacity of the battery must be known. Adjust the output of the mains adaptor to 1.17 times the nominal battery voltage plus 3.3 V, which is the potential across R1. Note that the adaptor must be capable of supplying a current of not less th...