Simple Auto Turn Off Battery Charger Circuit Diagram

This Auto Turn-Off Battery Charger Circuit Diagram for series-connected 4-cell AA batteries automatically disconnects from mains to stop charging when the batteries are fully charged. It can be used to charge partially discharged cells as well. The circuit is simple and can be divided into AC-to-DC converter, relay driver and charging sections. In the AC-to-DC converter section, transformer X1 steps down mains 230V AC to 9V AC at 750 mA, which is rectified by a full-wave rectifier comprising diodes D1 through D4 and filtered by capacitor C1. Regulator IC LM317 (IC1) provides the required 12V DC charging voltage.

 Auto Turn-Off Battery Charger Circuit Diagram

When you press switch S1 momentarily, the charger starts operating and the power-on LED1 glows to indicate that the charger is ‘on.’ The relay driver section uses pnp transistors T1, T2 and T3 (each BC558) to energise electromagnetic relay RL1. Relay RL1 is connected to the collector of transistor T1. Transistor T1 is driven by pnp transistor T2, which, in turn, is driven by pnp transistor T3. Resistor R4 (10-ohm, 0.5W) is connected between the emitter and base of transistor T3.

When a current of over 65 mA flows through the 12V line, it causes a voltage drop of about 650 mV across resistor R4 to drive transistor T3 and cut off transistor T2. This, in turn, turns transistor T1 ‘on’ to energise relay RL1.


Now even if the pushbutton is released, mains is still available to the primary of the transformer through its normally open (N/O) contacts.  In the charging section, regulator IC1 is biased to give about 7.35V. Preset VR1 is used for adjusting the bias voltage. Diode D6 connected between the output of IC1 and battery limits the output voltage to about 6.7V, which is used for charging the battery.  Pushing switch S1 latches relay RL1 and the battery cells start charging. As the voltage per cell increases beyond 1.3V, the voltage drop across resistor R4 starts decreasing. When it falls below 650 mV, transistor T3 cuts off to drive transistor T2 and, in turn, cuts off transistor T3.

As a result, relay RL1 de-energises to cut off the charger and red LED1 turns off.  You may determine the charging voltage depending on the NiCd cell specifications by the manufacturer. Here, we’ve set the charging voltage at 7.35V for four 1.5V cells. Nowadays, 700mAH cells are available in the market, which can be charged at 70 mA for 10 hours. The open-circuit voltage is about 1.3V. The shut-off voltage point is determined by charging the four cells fully (at 70 mA for 14 hours). After measuring the output voltage, add the diode drop (about 0.65V) and bias LM317 accordingly.

Author : Y.M. Anandavardhana

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USB Mobile Phone Battery Charger Circuit

USB Mobile Phone Battery Charger Circuit

This simple ambit can accord adapted 4.7 volts for charging a adaptable phone. USB aperture can accord 5 volts DC at 100mA accepted which is acceptable for the apathetic charging of adaptable phones. Most of the Adaptable Buzz batteries are rated 3.6 volts at 1000 to 1300 mAh. These array packs accept 3 NiMh or Lithium beef accepting 1.2 volt rating. Usually the array backpack requires 4.5 volts at 300-500 mA accepted for fast charging.

But low accepted charging is bigger to access the ability of the battery. The ambit declared actuality provides 4.7 adapted voltage and acceptable accepted for the apathetic charging of the adaptable phone. Transistor Q1 is acclimated to accord the adapted output. Any average ability NPN transistor like CL100, BD139, TIP122 can be used. Zener diode D2 controls the achievement voltage and D1 protects the polarity of the achievement supply. Front end of the ambit should be affiliated to a A blazon USB plug.

Connect a red wire to pin1 and atramentous wire to pin 4 of the bung for accessible polarity identification. Affix the achievement to a acceptable charger pin to affix it with the adaptable phone. After accumulating the circuit, admit the USB bung into the atrium and admeasurement the achievement from the circuit. If the achievement is OK and polarity is correct, affix it with the adaptable phone.
via

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Accu charger with IC LM723C

Circuit of 12 V accu / battery charger with IC LM723C. This Accu charger have input from the first transformer - voltage 220 initially V/110V/240V,  the input voltage lowered approximately 12 VAC, then voltage 12 Volts will be rectified by D1 and then filtered by C1 , then filtered and amplified again by IC LM723 and NPN transistor , output voltage is ready to use to charging the accu / battery.

Accu charger with IC LM723C

Part list :

T1 = Transformer , DC 12 V

D1 = Diode bridge

C1 = 470uF /50V

C2 = 1000pF

R1 = 4R7

R2 = 5K

R3 = 3K9

R4 = 7K5

R5 = 8K2

VR = 2K - 5K trim

TR1 = MJ2840

IC = LM723C

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AUTO fast battery charger for cars

This schema is a fast and auto car charger schema.By using this one you can charge your lead acid battery easily.After charging the battery this schema will cut off the power to your battery. so this is very useful schema for you.






Note

# use IC 7805 as power supply for this schema
# LM311 control test volt battery.
# Use PCB To build your schema.
# Be careful when you deal with 230v

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L200 Battery charger circuit

A actual simple array charger ambit accepting about-face polarity adumbration is apparent here.The ambit is based on IC L200 . L200 is a bristles pin capricious voltage voltage regulator IC.The charging ambit can be fed by the DC voltage from a arch rectifier or centermost broke rectifier.Here the IC L200 keeps the charging voltage constant.The charging accepted is controlled by the alongside aggregate of the resistors R2 & R3.The POT P1 can be acclimated to acclimatize the charging current.This ambit is advised to allegation a 12 V advance acerbic battery.The transistor t1,diode D3 and LED are acclimated to accomplish a array about-face indicator.In case the array is affiliated in about-face polarity ,the about-face polarity indicator red LED D5 glows.When the charging action is activity on the array charging indicator blooming LED D4 glows.
L200 Battery charger schema

Notes.

• The schema can be assembled on a good quality PCB or common board.

• The values of R2 & R3 can be obtained from the equation,

(R2//R3) =( V5-2)/(Io).

Where V5 is the charging voltage (voltage at pin 5) and Io is the charging current.

• The POT R8 can be used for fine adjustments of charging current.

• If battery is connected in reverse polarity the RED LED will glow.

• When the charging is going on the GREEN LED will glow.

• The rectified input voltage to the charger can be 18V.

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Controller of Solar charger Wiring diagram Schematic

 This is the simple Controller of Solar charger Circuit Diagram .When connecting a solar panel to a rechargeable battery, it is usually necessary to use a charge controller schema to prevent the battery from overcharging. Charge control can be performed with a number of different schema types. Lower power solar systems can use a series analog charge controller. Series regulators control the charging current by interrupting the flow of current from the solar panel to the battery when the battery reaches a preset full voltage. MPPT controllers use an inductor for energy storage and a high frequency switching schema to transfer the energy to the battery.

This schema is for a shunt-mode charge controller. In a shunt-mode schema, the solar panel is permanently connected to the battery via a series diode. When the solar panel charges the battery up to the desired full voltage, the shunt schema connects a resistive load across the battery to absorb the excess power from the solar panel. The main advantage of shunt-mode solar regulation is the lack of a switching transistor in the power path between the solar panel and battery. Switching transistors are non-perfect devices, they waste a percentage of available solar power as heat. Inefficiency in the shunt-mode controller’s switching transistor does not effect charging efficiency, it only turns on when excess power is purposely being wasted.

Controller of Solar charger Circuit Diagram 

Solar power is routed from the PV panel through the 1N5818 Schottky diode to the battery. When the battery reaches the full setpoint, the output on the lower half of the TLC2272 dual op-amp turns on. This activates the IRFD110 MOSFET transistor and connects the 68 ohm 3W load resistor to the battery. The load across the battery causes the battery voltage to drop, and the comparator schema turns back off. This oscillation continues while solar power is available. The 300nF capacitor across the op-amp slows the oscillation frequency down to a few hertz. The two 100K resistors in series provide a regulated 4.5V reference point for use as comparator reference points.

The 2N3906 transistor is wired with a zener diode in its base schema, when the PV voltage is above 12V, the 2N3906 transistor turns on and enables the comparator schema. The upper half of the TLC2272 op-amp inverts the dump load control signal, this is used to power the high intensity red LED. The LED turns on when the battery reaches the full setpoint. The LED does not waste any useful charging power since it only turns on when the battery is full.

The 78L09 IC provides 9V regulated power to the comparator schemary. Operational power for this schema is provided entirely from the PV panel, there is virtually no power taken from the battery at night.

This schema can be modified for higher amperage by replacing the 1N5818 diode, 68 ohm load resistor and IRFD110 MOSFET with higher power components. If the load resistor is connected directly across the PV panel at noon on a sunny day, the PV output voltage should drop to 12V or less. Higher power PV panels will require a resistor with lower ohms and a higher wattage rating. In cold climates, it may be useful to use the load resistor’s heat to keep the battery warm.

Operation of a high power version of this schema with a wind generator should be possible, although the author has not tried this. For a 20 amp version of this schema, the IRFD110 MOSFET should be replaced with an IRFZ44N and the 1N5818 schottky diode should be replaced with a 20L15T. Both of these parts should have large heat sinks. The 68 ohm/3W resistor should be changed to a much larger resistor, An 0.6 ohm/250W resistor would be able to handle 20 amps at 12V.

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Lead achid battery charger up to 3 battery

This circuit ti charger battery cells up to 3 battery , this charger use an IC LM301A , IC LM334 and transistor 2N3906 for major surgery on this charger circuit. Maximum input voltage 14 volt for 5 battery. Ouput voltage 2,35 volt 180 mA for 1 battery. And the charger input voltage must be filtered DC that is at least 3 Volt higher than maximum required output voltage.

See battery charger circuit below :

This is charger battery circuit

Above circuit furnishes an initial voltage of 2.5 Volt per Cell at 25 degree celcius to rapidly charge a battery . the charging current decreases as the battery cahrges , and when the current drop 180 mA , the charging circuit reduces the output voltage  to 2.35 V per cell, leaving the battery in a fully charged state.

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Solar Panel Lead Acid Batteries Charger

Solar Panel Lead-Acid Batteries Charger Schematic

This Batteries Charger is advised for charging closed lead-acid batteries with a solar console in baby and carriageable applications. The accepted diode that prevents the array from absolution through the solar console has been replaced by a FET-comparator combination.

The batteries charger will stop charging already a pre-set voltage (temperature compensated) has been reached, and recommence charging aback the voltage has alone off sufficiently. The amount is broken aback the array voltage drops beneath 11V and reconnected aback it gets aback to 12.5V.

The batteries charger ambit has the afterward features:

* Charges until Vbat = 13.8V (adjustable), again float charges;

* Shuts bottomward amount aback Vbat <11v (adjustable), resets at 12.5v;

* Temperature compensation;

* Will assignment with bargain and readily accessible apparatus like LM393 comparators and BUZ11 FETs;

* Uses beneath than 0.5mA aback application TLC393 comparators;

* Burns beneath than 20mW in FETs aback charging at 0,5A. (More big-ticket FETs with a lower RDSON will crop alike bigger results). Note that the charging accepted is bound alone by the solar console used.

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Build a Charger Extends Lead Acid Battery Life Wiring diagram Schematic

The Charger Extends Lead-Acid Battery Life Circuit Diagram furnishes an initial charging voltage of 2.5 V per cell at 25°C to rapidly charge a battery. The charging current decreases as the battery charges, and when the current drops to 180 mA, the charging schema reduces the output voltage to 2.35 V per cell, floating the battery in a fully charged state. 

This lower voltage prevents the battery from overcharging, which would shorten its life. The LM301A compares the voltage drop across R1 with an 18-mV reference set by R2. The comparator`s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-chaiging current passing through R1 drops below 180 mA. the 150-mV difference between the charge and float voltages is set by the ratio of R3 to R4. The LEDs show the state of the schema . 

Charger Extends Lead-Acid Battery Life Circuit Diagram

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Simple Hybrid Solar Charger Wiring diagram Schematic

In the electronic world D. Mohankumar is the most famous name his creations are very importent every time. Efficiency of a solar charging system depends on the weather conditions. Usually the solar panel gets four to five hours of bright sunlight in a day. If the weather is cloudy or rainy, it affects the charging process and the battery does not attain full charge. This simple hybrid solar charger can solve the problem as it can charge the battery using both solar power as well as AC mains supply. When output from the solar panel is above 12 volts, the battery charges using the solar power. When the output drops below 12 volts, the battery charges through AC mains supply. Fig. 1 shows the author’s prototype. 

 Fig. 1: Author’s prototype

Circuit and working

Fig. 2 shows schema for the hybrid solar charger, which is built around a 12V, 10W solar panel (connected at SP1), operational amplifier CA3130 (IC1), transistor BC547 (T1), 12V single-changeover relay (RL1), step-down transformer X1 and a few other components.

Fig. 2: Hybrid solar charger schema diagram

In bright sunlight, the 12V, 10W solar panel provides up to 17 volts DC with 0.6-ampere current. Diode D1 provides reverse polarity protection and capacitor C1 buffers voltage from the solar panel. IC1 is used as a simple voltage comparator. Zener diode ZD1 provides a reference voltage of 11 volts to the inverting input of IC1, while the IC’s non-inverting input gets voltage from the solar panel through R1.

Working of the schema is simple. When output from the solar panel is 12 volts or more, zener diode ZD1 conducts and provides 11 volts to the inverting terminal of IC1. Since its non-inverting input gets a higher voltage at this time, the output of the comparator turns high and the same is indicated by glowing green LED1. Transistor T1 then conducts and relay RL1 energizes. Thus the battery gets charging current from the solar panel through the normally-open (N/O) and common contacts of relay RL1.

LED2 indicates charging of the battery. Capacitor C3 is provided for clean switching of transistor T1. Diode D2 protects T1 from back EMF and diode D3 prevents the discharge of battery current into the schema.

When output from the solar panel drops below 12 volts, output of the comparator turns low and the relay de-energizes. Now the battery gets charging current from the transformer-based power supply through the normally-closed (N/C) and common contacts of the relay. This power supply comprises step-down transformer X1, rectifying diodes D4 and D5, and smoothing capacitor C4.

 Fig. 3: An actual-size, single-side PCB for the hybrid solar charger

Fig. 4: Component layout for the PCB

Construction and testing

An actual-size, single-side PCB for the hybrid solar charger is shown in Fig. 3 and its component layout in Fig. 4. After assembling the schema on PCB, enclose it in a suitable box. Use high-gauge (thick) wires to connect the solar panel and the battery to the schema.

To test the schema for proper functioning, remove the solar panel from connector SP1 and connect a DC variable voltage source. Set some voltage below 12V and slowly increase it. As the voltage reaches 12V and goes beyond, the logic at test point TP2 changes from low to high. The transformer-based power supply voltage can be checked at test point TP3.

Sourced By: EFY Author : D.Mohnkumar

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