Lithium battery charger circuit principle

Charging chip for TP4056 what we choose, the chip peripheral device is less, the cost is not high also, a few dollars to buy a heap, the schematic diagram can also clearly see that the device has: TP4056 a, a 1.2 K resistor (here the resistance the smaller the charging current, the greater the minimum is 1.2 K, because the chip support maximum charging current is 1 a, is 1.2 K resistor values), a 0.4 Ω resistance, two 1 K resistor, LED lights (red light and green light for instructions The battery Charging charging status, for the green light, red light), two 10 uf capacitance, considering the practical should also have hole hole plate, connecting plate (with 4056 chip is small, not convenient manual welding), row needle, row mother, solder and dupont line, etc.

Required materials (pictured above with no 1 k current-limiting resistor, actually should have)

With material we next job is to put the circuit according to the principle diagram welding, due to the smaller 4056 so we chose the adapter plate, the first 4056 welded to the adapter plate.

Note: pay attention to the chip pins must not even one piece! Required materials (pictured above with no 1 k current-limiting resistor, actually should have)

With material we next job is to put the circuit according to the principle diagram welding, due to the smaller 4056 so we chose the adapter plate, the first 4056 welded to the adapter plate.

Note: pay attention to the chip pins must not even one piece!

Welded to the hole hole plate

Well so far, the most important components, is also the most difficult welding device has welding is successful, the next work we is the peripheral devices are welded to the hole hole plate, as for the need to pay attention to place, is mainly electrolytic capacitor and the LED is negative, the welding of time attention don't reverse, otherwise can't work normally, and is in good welding parts, some components pins are very long, there may be a pin bare behind the board, details as below

Pin bare

This kind of phenomenon is inevitably encountered in the process of welding, welding or not good at hand for the first time friends to pay attention to, because behind the wire is fine, so do be careful not to the eyes, had better wear glasses when welding, to avoid pin exposed too much, the welding part components after remember to cut off the pins in time in case of an accident.

We step by step, according to the principle diagram welding, because the device is less, so it wouldn't consume too much time, one more welding successfully.

rendering

From here to see the board, you can see there are two rows of needle, the above is to connect the power supply section, including the pins as is above, below that is negative, the input voltage is 5 v, can use the USB power supply, power supply also can choose any other way, but the voltage is 5 v, don't too much, nor too low, below it was connected to the rechargeable batteries for pin part, leave the needle socket, convenient for dupont line inserted, the above is the battery negative, that is the power supply is below, if rechargeable battery voltage of 3.7 v, with a few batteries it doesn't matter, don't give 1.2 v battery, because the voltage is higher than the normal charging voltage of 1.2 v may burn the battery.

To 18650 charging status

The picture above for18650 lithium batteries Charge will figure, it seems that we made a success, at the time of normal charging, the red light is lit up, the charging current is controlled in 1 a, the voltage at around 4.2 v, enough to satisfy most said the battery requirements, when the battery is full of light green light, red light off, then the output current is close to zero.

Full of rendering (without battery, the battery when take off)

After testing we make very successful, friends, are you ready to order, also etc. What also don't hurry to make a, at the time of production must pay attention to safety!

This circuit with the function of charging status display, the red light flash is charged, the green flash will soon filled with completely filled with green light. As long as you have 12 V power supply can be, don't install batteries, after taking the circuit the lower right corner of adjustable resistance, make the battery output is 4.2 V, and the lower left corner of the adjustable resistance make LM358 3 feet is 0.16 V, the charging current is 380 ma, super fast, three diode is dropping, and even prevent the LM317 overheating, and the LM317 are required to add heat sink, the triode in the graph can be any type

The lithium battery Fast automatic charger circuit. Lithium battery can be large current charging, but single section lithium battery charging voltage of the maximum value no more than 4.2 V, if more than 4.5 V, it may cause permanent damage. Lithium battery discharge voltage shall be not less than 2.2 V, otherwise will may cause permanent damage. This circuit adopted LM3420-8.4 special lithium battery charging controller. When battery voltage is lower than 8.4 V, LM3420 output terminal (1) the foot (OUT) the output current, transistor Q2 deadline, therefore, adjustable voltage stabilizer LM317 output constant current, its current value depends on the value of RL.

Lithium ion batteries Charging higher requirements. Overcharge will cause the battery scrap. Using the minimalist charging circuit of figure 1 never overcharge. The circuit by 1 u F capacitance will be charging current will be limited to about 70 ma.TL431 connect into 4.2 V voltage source parallel on both ends of the battery. When the battery voltage is lower than 4.2 V, TL431.All current into the battery. When the battery voltage rises to about the 4.2 V, TL431 began to play a role of shunt, when the battery voltage of 4.2 V, current all inflows TL431.At this point, the TL431 power consumption is 0.3 W, shall not exceed the maximum power consumption. Due to the charging current is smaller. So the charging time is longer than the is its disadvantages. Circuit, R2 and R3 resistance must be accurate. Whether can measure TL431 ends before access to the battery is 4.2 V. This circuit with 220 v alternating current transformer isolation, so should be inserted again after connected battery one outlet, to ensure personal safety.

Once charging battery run out of nowhere, you can only be embarrassing,, can see a lot in the market for mobile phone emergency charger, charging with sanyo's "love wife" series, a cheap knock-off of section 5, the battery can charge of external rods. But shanzhai section 5, the battery bar has a charging current is small, the battery is not durable, hasn't charge much electricity section battery was OVER, the built-in pulse circuit of high frequency pulse charging and may damage to the electrical appliances itself."Sanyo" love wife need to cooperate with their own rechargeable batteries, or commercial and other power supply box, use the built-in lithium battery powered.

Section 8 battery box: 1.5 Yuan, 3 a fuse: 0.1 Yuan, the small switch: 0.5 Yuan, 470 uf capacitor: 0.2 Yuan, USB port: 0.5 Yuan, diode: 0.1 Yuan, a heat shrinkable tube.

Soldering iron, tweezers, scissors.

Ideas: as you all know, 5 standard of nimh batteries voltage is 1.2 V working voltage 1.15 V - 1.35 V4 section after the series voltage range between 4.6 V - 5.4 V, this is the standard of compound USB voltage (5 V for USB standard voltage allows the positive and negative floating) 5 factory of alkaline battery voltage is 1.5 V peak at about 1.6 V commonly 4 section voltage 6 V -- -- -- -- -- - 6.4 V (this surpassed the standard USB voltage, direct usage will burn out the USB device is connected, so consider using a diode to step down, the pressure drop of the crystal diode voltage after the pressure drop is less than 0.7 V position seemingly high voltage of 5.3 V to 5.7 V, but due to the circuit and battery internal resistance, when actual charging voltage tends to just more than 5 V, safety voltage)

In order to try to be on the appearance is beautiful, I use this time a 8 section 5 battery pack as the main materials of the production. Battery box only to one of the four part series, on the other side to other circuit part of the occupied space.

Circuit diagram: (be sure to make clear the definition of USB4 a stitch, don't wrong!)When the switch is off for the alkaline battery step-down mode for rechargeable battery mode when switch is closed (I use section 4-2500 mah ni-mh rechargeable battery)

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