Different Types of Adapter
An electric current flowing in one direction only.
Therefore, the direct current remains flowing in a constant direction, with no changes in frequency or polarity. DC adaptor converts AC electricity into DC electricity. For example, a 12 V DC adaptor will convert 120 V AC at 60 Hz into 12 V DC.
A DC adaptor is also rated for maximum power output in watts. Therefore, a 12 V DC adaptor rated at 36 W will also be capable of a maximum output of 3 A, but the difference is that the current is constant, flowing in one direction, rather than the constantly reversing alternating current that the AC adaptor puts out.
Universal power adapters are unlike the power adapter that ships with your notebook. The most obivous difference is that the aftermarket adapter include a variety of tips. Each tip has a unique fitting to accommodate as many manufactures’ hardware as possible. Vendors use a range of voltages, and varied sizes help prevent connectivity between incompatible components.
The Air AC adapter will power your laptop from an AC wall outlet, automobile cigarette lighter socket, Airline seat power plug. The adapter has a USB port that can be used to change devices such as cell phones, PDAs, digital cameras and more.
Laptop Adapter Voltages
The voltages is slightly more than a multiple of the fully charged voltage of a Lithium Ion battery-the type used in almost every modern laptop. Large scale of laptops use Lithium Ion batteries. 19 V provides a voltages which is suitable for use for charging up to 4 multiply Lithium Ion cells in series using a buck converter to drop the excess voltage efficiently. (Various combination of series and parallel cells can be fitted) (Voltages slightly below 19 V is a useful standard voltage that will meet most eventualities)(Almost all modern laptops use Lithium Ion batteries. Each battery consists of at least a number of Lilon cells in a series ‘string’ and may consists of a number of parallel combinations of several series strings)
A Lithium Ion cell has a maximum charging voltages of 4.2. To charge a 4.2 V cell at least slightly more voltage is required to provide some “headroom” to allow charge control electronics to function. At the very least about 0.1 V extra might do but usually at least 0.5 V would be useful and more might be used. It is usual for a charger to use a switched mode power supply to convert the available voltages to required voltages. A SMPS can be a Boost or swap from one the other as required. In many cases a buck converter can be made more efficient than a boost coverter. In this case, using a buck converter it would be possible to charge up to 4 cells in series.
There are laptop batteries with
3 cells in series (3S),
4 cells in series (4S),
6 cells in 2 parallel strings of 3 (2P3S)
8 cells in 2 parallel strings of 4 (2P4S)
and with a sources voltages of 19 V it would be possible to charge 1, 2, 3, or 4 Lilon cells in series and many number of parallel strings of these.
For cells at 16.8 V leave a headroom of 2.4 volt for the electronics. Most of this is not needed and the difference is accommodated by the buck converter, which acts as ” electronic gearbox”, taking in energy at one voltage and outputting it at a lower voltage and appropriately higher current.
With say 0.7 V of headroom it would notionally be possible to use say 16.8 V+ 0.5 V = 17.5 V from the power supply- but using 19 V ensures that there is enough for any eventuality and the excess is not wasted as the buck converter converts the voltages down as required. Voltage drop other than in the battery can occur in SMPS switch, SMPS diodes, wiring, connectors, resistive current, sense elements and protection circuitry. As little drop as possible is desirable to minimise energy wastage.
Universal Adapter & its Types:-
You may need to buy an adapter that will fit another country’s outlet in order to use your favourite devices abroad. Finding the right adapter for a particular trip is simply a matter of researching the outlets used in your destination and buying the right ones to match your two-and three-pronged plugs. However since voltage also varies by country, it’s important to then check if you’ll need a converter as well for any of your devices. But with some careful planning ahead of time, you can minimize the need for both.
. Count the prongs to your devices’ plugs
Before you start looking for adapters, determine exactly which devices you’ll be bringing along on your trip. You’ll need to refer to each one later on for additional information, but for now. Expect them to have either two or three prongs.
. Two-pronged plugs are known as “unearthed” or “ungrounded” while the extra prong in a three pronged plug means that it’s “earthed’ or “grounded”
. The extra prong in an earthed or grounded plug is known as an ‘earth pin” or ‘grounding pin”. This is a safety features typically for devices made of metal or other conductive material to reduce the chances of electrical shock
. Research plug types.
Expect the design of electrical outlets to vary country by country, or even region by region. Compose a list of each country that you will be visting. For each one, search online for which types of design are used in that country so you can find adapters shaped to match
. Design for outlets and plugs are typically expresed in letters. For example, an American device with two prongs to its plug is type A, while an American device with three prongs is type B.
. Distinguish between “grounded” and “ungrounded”
When researching plug types, expect to find more than one listed for most countries. If there are only two listed, one is most likely for grounded electronics, and the other for ungrounded. For each plug type you find for that country, count the number of prongs. If one has two prongs and the other has three, this means one is for ungrounded electronic and other for grounded. If any of the devices that you’re bringing have three prongs, you will need a corresponding grounding adapter for those item
Confirm your hotel’s plug type, if needed. expect many countries to stick to only one or two plug types. However if your search turns up multiple types in one country contact the hotel where you will be staying and/ or wherever else you expect to need your electronic the most. Ask them which type of electrical outlets they have
Adapter Polarity Identification;- For direct currents, there is a positive pole(+) and a negative pole(-). For an adapter to work the positive plug must mate with a negative receptable or vice versa. direct current by nature is a one way street and things just won’t work if you try to go up the downspout.
If you multiply the voltage by the current you get the wattage. But the number of watts alone won’t tell you if the adapter is right for your device.
To check the polarity, look for a + or – sign next to the voltage. Or look for a diagram showing the polarity. It will usually consists of three circles, with a plus or minus on either side and solid circle or C in the middle.If the + sign is on the right, then the adapter has positive polarity;
If there is a – sign on the right then it has negative polarity:
Next you want to look at your devices for the DC input. You’ll usually see at least the voltage near the Dc plug receptable. But you also want to make sure the current matches, too.
You might find both the voltage and the current elsewhere on the device, on the bottom or inside a battery compartment cover or in the manual. Again, look for the polarity, by either noting a + or – symbol or the polarity diagram.
Remember: the input of the device should be the same as the output of the adapter. This includes polarity. If the devices has a DC input get an adapter that has a dc a universal adapter,make sure it has the proper current rating and that you choose the correct voltages and polarity.
Adapter Opening Method:-
When the power cable breaks or gets cut, you can either buy a new adapter or attempt to repair the existing one. Repairing the AC adapter will require you to access the inside. To complete this task you will require one or more common procedures.
. Unplug the power cord from the wall outlet or power strip, if it is still plugged in.
.Disconnect the power cable from the laptop, if necessary.
. Place the end of a putty knife in the seam of the AC adapter. The seam is the middle or where the top and bottom halves of the adapter meet.
. Srparate the top half of the adapter from the bottom half, to expose the internal structure of the adapter.
Adapter Board Components
Adapter Board Components:-
SM Transformer:- a switch mode power supply is usually powered from a D.C. source, such as a battery. The switching mode power supply coverts the input DC sources. The power supplies are often referred to as DC to DC coverters….. A switch mode power transformer can have several secondary windings.
Switch mode power transformers get their name from the switchning action needed to sustain transformer operation. by controlling the amount of on time and off time of the switches, one can also control the amount of power delivered to the transformer load. The voltage can be fed to the switch mode power transformer inn voltage pulses. The pulse duration is a portion of an overall cycle time. The cycle time is equal to the inverse of the operating frequency. The terms duty cycle and pulse width modulation arise from the control of the switching on time and off time.
Bridges Rectifier Diode:-Bridge rectifier consists of four diodes, which are connected in the form of bridge: hence, these types of rectifiers are termed as bridges rectifier. Different types of diodes are used for designing bride wave rectifier. These diodes are classified based on the voltages and current ratings of the diodes. Thus bridges can be classified based on the voltages and current ratings of the diodes. Thus, bridges wave rectifiers designed using diodes are called as uncontrolled rectifiers and rectifiers designed using thyristors are called as controlled as controlled rectifiers. Let us start with diosdes that are typically used to implement bridges wave rectifier.
NTC ( Negative Temperature Coefficient ):- The NTC thermistor is widely used in many application for a variety of purpose where a negative temperature coefficient is required.
Being an NTC thermistor the resistance falls as the temperature increases, making it particulary useful in a number of different areas. As the name indicates, the NTC thermistor provides a reduction in resistance for an increase in thermistor body temperature.
Fuse:– Fuse is a piece of wire of a material with a very low melting point. When a high current flows through the circuit is broken and current stops flowing.
It must be remembered that fuse wire is always connected to the LIVE wire
Properties of Reliable fuse:- Fuse must be of correct value. For example in a 15A circuit the fuse wire used is thick and of 15A rating.
Oscillator IC:- An oscillator is a mechanical or electronic device that works on the principles of oscillation: a periods fluctuation between two things based on changes in energy. Computers clocks watches radio and metal detectors are among the many devices that use oscillators.
A clock pendulum is a simple type oscillator. The most accurate timepiece in the world, the atomic clock, keeps time according to the oscillation within atoms. Electronic oscillators are used to generate signals in computers, wireless receivers and transmitters, and audio-frequency equipment,particularly music synthesizers. There are many types of electronic oscillators, but they all operate according to the same basic principle: an oscillator always employes a sensitive amplifier whose output is fed back to the input in phase. Thus, the signal regenerates and sustain itself. This is known as positive feedback. It is the same process that sometimes causes unwanted “howling” in public – address system.
Opto Coupler:- The basic design of an opt coupler, also known as an Opto-isolator, consists of an LED that produces infra – red light and a semiconductor photo-sensitive device that is used to detect the emitted infra-red beam. Both the LED and photo-sensitive device are enclosed in a light-tight body or package with metal legs for the electrical connections as shown.
MOSFET make very good electronic switches for controlling loads and in CMOS digital circuit as they operate between their cut-off and saturation regions.
MOSFET( Metal Oxide Semiconductor Field Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic devices. The MOSFET is a core of integrated circuit and it can be designed and fabricated in a single chip because of these very small sizes. The MOSFET is a four terminal devices with sources(S) gate(G) drain(D) and body(B) terminals. The body of the MOSFET is frequently connected to the source terminal so making it a three terminal device like field effect transistor. The MOSFET is very far the most common transistor and can be used in both analog and digital circuit.
An electrolytic capacitor is a polarized capacitor which uses an electrolyte to achieve a large capacitance than other capacitor types.
An electrolytic capacitor is a type of capacitor that uses an electrolyte to achieve a large capacitance than other capacitor types. An electrolyte is a liquid or gel containing a high concentration of ions. Almost all electrolyte capacitors are polarized, which means that the voltage on the positive terminal must always be greater than the voltages on the negative terminal. The benefit of large capacitance in electrolytic capacitors comes with several drawbacks as well.
AC adapter Block Diagram:-
Adapter Circuit view:-
WHAT IS BATTERY
A battery is a hardware component that supplies power to a device, enabling that device to work without a power cord. Batteries are often capable of powering a laptop computer for several hours depending on how much power it requires. Today, many high-end devices such as computer laptops and cell phones use rechargeable batteries that allow a user to recharge the battery once depleted of energy. The picture below is an example of what a laptop battery may look like when removed from the laptop, with a close-up of the battery rating.
Different types of Laptop Batteries:-
Lithium-ion: This type is lightweight and performs better than the other types of batteries. Unlike NiCad or NiMh batteries, lithium-ion batteries don’t have the dreaded”memory effect.” The memory effect is the property of nickel-cadmium batteries that causes them to lose their capacity for full recharging if they are discharged repeatedly the same amount and then recharged without overcharge before they have fully drained. There’s usually a rapid-charging option with lithium-ion batteries, which is good when you’re in a time crunch. Finally, this type of battery is more environmentally friendly than the other types.
Two older types of batteries, once popular in portable computers, are nickel-cadmium (NiCad) and nickel-metal hydride (NiMH). The NiCad isn’t often considered for laptops these days because it suffered unpleasantly from the Dreaded memory effect. A NiMH battery is longer lasting than a NiCad, but it too woefully suffers from The Dreaded Memory Effect.
. You can confirm which type of battery your laptop has by looking at its label.
. A few laptop computers out there are still using NiMH batteries. This is fine, of course, but you might want to check to see whether you can find a battery upgrade to the Li-ion type.
. To prolong the life of a NiMH battery, recommend fully discharging it every so often. For example, after you use, drain, and recharge the NiMH battery about four times do a complete drain and then recharge it again. That should help the battery last a bit longer.
. Your laptop might have two additional batteries inside. a secondary, alkaline battery inside is used to power the laptop internal clock. An optional third battery keeps things powered for the minute or so that it takes you to swap out the main battery with a fresh one.
Battery Cells Connectivity Method:-
Some packs may consist of a combination of series and parallel connections. Laptop batteries commonly have four 3.6V Li-ion cells in series to achieve a nominal voltage 14.4V and two in parallel to boost the capacity from 2,400mAh to 4,800mAh. Such a configuration is called 4s2p, meaning four cells in series and two in parallel. Insulating foil between the cells prevents the conductive metallic skin causing an electrical short.
Most battery chemistries lend themselves to series and parallel connection. it is important to use the same battery type with equal voltage and capacity (Ah) and never to mix different makes and sizes. A weaker cell would cause an imbalance. this is especially critical in a series configuration because a battery is only as a string as the weakest link in the chain.
A weak cell may not fail immediately but will get exhausted more quickly than the strong ones when on a load. On charges, the low cell fills up before the strong ones because there is less to fill and it remains in over-charges longer than the other. On discharges, the weak cell empties first and gets hammered by the stronger brothers. Cells in multi- packs must be matched, especially when used under heavy loads
The single-cell configuration is the simplest battery pack; the cell does not need matching and the protection circuit on a small Li-on cell can be kept simple. typical examples are mobile phones and tablets with one 3.60V Li-ion cell. Other uses of a single cell are wall clocks, which typically use a 1.5V alkaline cell, wristwatches and memory backup, most of which are very low power applications.
The nominal cell voltage for a nickel-based battery is 1.2V, alkaline is 1.5V; silver oxide is 1.6V and lead acid is 2.0V. Primary lithium batteries range between 3.0V and 3.9V. Li-ion is 3.6v; Li-phosphate is 3.2V and Li-titanate is 2.4V.
portable equipment needing higher voltages use battery packs with two or more cells connected in series. Figure 2 shows a battery packs with four 3.6V Li-ion cells in series also known as 4S, to produce 14.4V nominal. In comparison, a six-cell lead acid string with 2V/cell will generate 12V, and four alkaline with 1.5V/cell will give 6V.
if higher currents are needed and larger cells are not available or do not fit the design constraint one or more cells can be connected in parallel. Most battery chemistries allow parallel configurations with little side effect. Four cells connected in parallel in a P4 arrangement. The nominal voltages of the illustrated pack remains at 3.60V, but the capacity and runtime are increased fourfold A cell that develops high resistance or opens is less critical in a parallel circuit than in a series configuration, but a failing cell will reduce the total load capability. It’s like an engine only firing on the three cylinders instead of on all four. An electrical short, on the other hand, is more serious as the faulty cell drains energy from the other cells, causing a fire hazard. Most so-called electrical shorts are mild and manifest themselves as elevated self-discharge.
Series/ parallel Connection:
The series/parallel configuration shown in Figure 6 enables design flexibility and achieves the desired voltage and current rating with a standard cell size. The total power is the sum of voltage times current; a 3.6V cell multiplied by 3,400mAh produces 12.24Wh. Four 18650 energy cells of 3,400mAh each can be connected in series and parallel as shown to get 7.2v nominal and a total of 48.96Wh. a combination with 8 cells would produce 97.92 Wh the allowable limit for carry on a aircraft or shipped without Class 9 hazardous material. The slim cell allows flexible pack design but a protection circuit is need
Laptop Battery inside View:-
External battery view
Laptop battery inside Circuit:-
How to increase Battery Life:- battery technology has improved considerably over the last few years, but few laptops can still last a full working day working day between recharges.
There are some steps you can take to stretch out battery life for as long as possible when you’re away from a power socket, and while this list of tips won’t have a dramatic effect, they will still make a noticeable difference.
. Reduce the screen Brightness:- The bright lights behind a laptop screen are one of the biggest power drains, so keep the brightness low when running on battery alone
Laptops have keyboard shortcuts to adjust the screen brightness, usually accessed by pressing the Fn key, so learn them and use them
On windows 10, you can open the action center and select brightness iron to reduce it.
. Reduce the screen time-out and set standby time :- set the screen to turn itself off after one minute or of inactivity. In windows 10, search for power options from the start menu them select power and sleep settings.
From each drop down box, reduce the time it takes for your PC’s screen turn off and how long it should wait until fully entering sleep mode. A couple of minutes of inactivity is a reasonable time
. Turn off Wi-Fi;- unless you’ reconnected to a wireless network when you’re out and about, turn off your laptop’s Wi-Fi wireless network connection-it’s another power waster.
On Windows 10, the quickest way to do this is by opening the action center and clicking the Wi-Fi iron.
. Turn of Bluetooth:- likewise, Bluetooth is a big drain on the battery when not in use in the Action Center, you can click the Bluetooth icon to switch it off.
. Close unused application:- just because windows can run several Applications at the same time doesn’t mean you should keeping several Applicalions open at once places an extra burden on the laptop’s processror and uses up valuable memory.
Windows will start to use hard disk space as ‘virtual’ memory when the laptop’s actual memory is full, and this too uses extra power. close any applications and web browser tabs that aren,t being used and consider a memory upgrade if your laptop only has 2GB RAM- this will make it feel a bit faster, too.