top of page

7th Pastor & Wife Appreciation Celebration Group

Public·33 members
Martin Novikov
Martin Novikov

Where To Buy Power Cord For Macbook Pro _HOT_

I keep my macbook pro plugged in all the time with no adverse effects. And if you want to use your mac laptop in clam-shell mode (ie lid closed, connected to an external monitor), then you will need the power supply plugged in anyway.

where to buy power cord for macbook pro

Lets take an example of an ideal situation where you bought a new macbook and used it for 10 years constantly plugged in with just 1 charge cycle , how many hours of battery backup you'll expect out of that 10 years old macbook.

PlugBug Duo snaps onto your MacBook power adapter giving you the ability to charge your MacBook plus two additional USB powered devices, such as your iPhone and AirPods, from one outlet. Imagine how awesome that would be in an airport or a coffee shop where outlets are scarce. No more having to decide which item to charge before you board a plane or on a break at a conference.

MagSafe is a series of proprietary magnetically attached power connectors developed by Apple Inc. for Mac laptops. MagSafe was introduced on January 10, 2006, in conjunction with the MacBook Pro, the first Intel-based Mac laptop, at the Macworld Expo. The connector is held in place magnetically so that if it is tugged (for example, by someone tripping over the cord) it will pull out of the socket without damaging the connector or the computer power socket, and without pulling the computer off its surface.[1] A thinner and wider version, called MagSafe 2, was introduced in 2012. It was discontinued across Apple's product lines between 2016 and 2019 and replaced with USB-C. MagSafe returned to Mac laptops with the introduction of updated MacBook Pro models with MagSafe 3 in 2021.

The MacBook and the 13-inch MacBook Pro use a 60 W MagSafe charger, whereas the 15- and 17-inch MacBook Pro use an 85 W version. The MacBook Air used a lower-powered 45 W version. According to Apple, an adapter with a higher wattage than that originally provided may be used without problems.[12]

Bottom line: The extra-long 10-foot length gives you more room to maneuver and work in environments where you may find yourself far from an outlet. It features a premium, nylon, braided cord and is outfitted with power delivery 4.0/3.0 and QC fast charging technology. It supports up to a 100W output, so you can fast charge your MacBook up to 50% in 35 minutes. Its built-in E-Mark chip auto-adjusts power delivery, so your device only gets as much as it needs.

Even if the battery is fully charged, this problem can still occur, making it a confusing and troubling issue if you are experiencing it. Computers affected by this issue seem to only work correctly when connected to a power cord, which limits the functionality of your MacBook.

According to Apple, it is acceptable to use power adapters with different wattages with MacBooks with a caveat. When using a charger from MacBook Air with a more powerful MacBook Pro expect a longer charging time.

Inside the Macbook charger. Many electronic components work together to provide smooth power to your laptop.Most consumer electronics, from your cell phone to your television, use a switching power supply to convert AC power from the wall to the low-voltage DC used by electronic circuits.The switching power supply gets its name because it switches power on and off thousands of times a second, which turns out to be a very efficient way to do this conversion.[1]Switching power supplies are now very cheap, but this wasn't always the case.In the 1950s, switching power supplies were complex and expensive, used in aerospace and satellite applications that needed small, lightweight power supplies.By the early 1970s, new high-voltage transistors and other technology improvements made switching power supplies much cheaper and they became widelyused in computers.[2]The introduction of a single-chip power supply controller in 1976 made switching power supplies simpler, smaller, and cheaper.Apple's involvement with switching power supplies goes back to 1977 when Apple's chief engineer Rod Holt designed a switching power supply for the Apple II.According to Steve Jobs:[3]"That switching power supply was as revolutionary as the Apple II logic board was. Rod doesn't get a lot of credit for this in the history books but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."This is a fantastic quote, but unfortunately it is entirely false.The switching power supply revolution happened before Apple came along, Apple's design was similar to earlier power supplies[4]and other computers don't use Rod Holt's design.Nevertheless, Apple has extensively used switching power supplies and pushes the limits of charger design with their compact, stylish and advanced chargers.Inside the chargerFor the teardown I started with a Macbook 85W power supply, model A1172, which is small enough to hold in your palm. The picture below shows several features that can help distinguish the charger from counterfeits: the Apple logo in the case, the metal (not plastic) ground pin on the right, and the serial number next to the ground pin.Apple 85W Macbook chargerStrange as it seems, the best technique I've found for opening a charger is to pound on a wood chisel all around the seam to crack it open. With the case opened, the metal heat sinks of the charger are visible. The heat sinks help cool the high-power semiconductors inside the charger. Inside the Apple 85W Macbook chargerThe other side of the charger shows the circuit board, with the power output at the bottom. Some of the tiny components are visible, but most of the circuitry is covered by the metal heat sink, held in place by yellow insulating tape.The circuit board inside the Apple 85W Macbook charger. At the right, screws firmly attach components to the heat sinks.After removing the metal heat sinks, the components of the charger are visible. These metal pieces give the charger a substantial heft, more than you'd expect from a small unit.Exploded view of the Apple 85W charger, showing the extensive metal heat sinks.The diagram below labels the main components of the charger.AC power enters the charger and is converted to DC.The PFC circuit (Power Factor Correction) improves efficiency by ensuring the load on the AC line is steady. The primary chops up the high-voltage DC from the PFC circuit and feeds it into the transformer. Finally, the secondary receives low-voltage power from the transformer and outputs smooth DC to the laptop.The next few sections discuss these circuits in more detail, so follow along with the diagram below.The components inside an Apple Macbook 85W power supply.AC enters the chargerAC power enters the charger through a removable AC plug.A big advantage of switching power supplies is they can be designed to run on a wide range of input voltages.By simply swapping the plug, the charger can be used in any region of the world, from European 240 volts at 50 Hertz to North American 120 volts at 60 Hz.The filter capacitors and inductors in the input stage prevent interference from exiting the charger through the power lines. The bridge rectifier contains four diodes, which convert the AC power into DC. (See this video for a great demonstration of how a full bridge rectifier works.)The input components in a Macbook charger. The diode bridge rectifier is attached to the metal heat sink with a clip.PFC: smoothing the power usageThe next step in the charger's operation is the Power Factor Correction circuit (PFC), labeled in purple.One problem with simple chargers is they only draw power during a small part of the AC cycle.[5]If too many devices do this, it causes problems for the power company.Regulations require larger chargers to use a technique called power factor correction so they use power more evenly.The PFC circuit uses a power transistor to precisely chop up the input AC tens of thousands of times a second; contrary to what you might expect, this makes the load on the AC line smoother. Two of the largest components in the charger are the inductor and PFC capacitor that help boost the voltage to about 380 volts DC.[6]The primary: chopping up the powerThe primary circuit is the heart of the charger.It takes the high voltage DC from the PFC circuit, chops it up and feeds it into the transformer to generate the charger's low-voltage output (16.5-18.5 volts). The charger uses an advanced design called a resonant controller, which lets the system operate at a very high frequency, up to 500 kilohertz. The higher frequency permits smaller components to be used for a more compact charger. The chip below controls the switching power supply.[7]The circuit board inside the Macbook charger. The chip in the middle controls the switching power supply circuit.The two drive transistors (in the overview diagram) alternately switch on and off to chop up the input voltage. The transformer and capacitor resonate at this frequency, smoothing the chopped-up input into a sine wave.The secondary: smooth, clean power outputThe secondary side of the circuit generates the output of the charger.The secondary receives power from the transformer and converts it DC with diodes. The filter capacitors smooth out the power, which leaves the charger through the output cable.The most important role of the secondary is to keep the dangerous high voltages in the rest of the charger away from the output, to avoid potentially fatal shocks.The isolation boundary marked in red on the earlier diagram indicates the separation between the high-voltage primary and the low-voltage secondary. The two sides are separated by a distance of about 6 mm, and only special components can cross this boundary.The transformer safely transmits power between the primary and the secondary by using magnetic fields instead of a direct electrical connection.The coils of wire inside the transformer are triple-insulated for safety.Cheap counterfeit chargers usually skimp on the insulation, posing a safety hazard.The optoisolator uses an internal beam of light to transmit a feedback signal between the secondary and primary. The control chip on the primary side uses this feedback signal to adjust the switching frequency to keep the output voltage stable.The output components in an Apple Macbook charger.The two power diodes are in front on the left. Behind them are three cylindrical filter capacitors.The microcontroller board is visible behind the capacitors.A powerful microprocessor in your charger?One unexpected component is a tiny circuit board with a microcontroller, which can be seen above.This 16-bit processor constantly monitors the charger's voltage and current.It enables the output when the charger is connected to a Macbook, disables the output when the charger is disconnected, and shuts the charger off if there is a problem.This processor is a Texas Instruments MSP430microcontroller,roughly as powerful as the processor inside the original Macintosh.[8]The microcontroller circuit board from an 85W Macbook power supply, on top of a quarter. The MPS430 processor monitors the charger's voltage and current.The square orange pads on the right are used to program software into the chip's flash memory during manufacturing.[9]The three-pin chip on the left (IC202) reduces the charger's 16.5 volts to the 3.3 volts required by the processor.[10]The charger's underside: many tiny componentsTurning the charger over reveals dozens of tiny components on the circuit board. The PFC controller chip and the power supply (SMPS) controller chip are the main integrated circuits controlling the charger.The voltage reference chip is responsible for keeping the voltage stable even as the temperature changes.[11]These chips are surrounded by tiny resistors, capacitors, diodes and other components.The output MOSFET transistor switches the power to the output on and off, as directed by the microcontroller. To the left of it, the current sense resistors measure the current flowing to the laptop.The printed circuit board from an Apple 85W Macbook power supply, showing the tiny components inside the charger.The isolation boundary (marked in red) separates the high voltage circuitry from the low voltage output components for safety.The dashed red line shows the isolation boundary that separates the low-voltage side (bottom right) from the high-voltage side.The optoisolators send control signals from the secondary side to the primary, shutting down the charger if there is a malfunction.[12]One reason the charger has more control components than a typical charger is its variable output voltage.To produce 60 watts, the charger provides 16.5 volts at 3.6 amps. For 85 watts, the voltage increases to 18.5 volts at 4.6 amps. This allows the charger to be compatible with lower-voltage 60 watt chargers, while still providing 85 watts for laptops that can use it.[13]As the current increases above 3.6 amps, the circuit gradually increases the output voltage. If the current increases too much, the charger abruptly shuts down around 90 watts.[14]Inside the Magsafe connectorThe magnetic Magsafe connector that plugs into the Macbook is more complex than you would expect. It has five spring-loaded pins (known as Pogo pins) to connect to the laptop. Two pins are power, two pins are ground, and the middle pin is a data connection to the laptop.The pins of a Magsafe 2 connector. The pins are arranged symmetrically, so the connector can be plugged in either way.Inside the Magsafe connector is a tiny chip thatinforms the laptop of the charger's serial number, type, and power.The laptop uses this data to determine if the charger is valid.This chip also controls the status LEDs.There is no data connection to the charger block itself; the data connection is only with the chip inside the connector.For more details, see my article on theMagsafe connector.The circuit board inside a Magsafe connector is very small. There are two LEDs on each side. The chip is a DS2413 1-Wire switch.Operation of the chargerYou may have noticed that when you plug the connector into a Macbook, it takes a second or two for the LED to light up. During this time, there are complex interactions between the Macbook, the charger, and the Magsafe connector.When the charger is disconnected from the laptop, the output transistor discussed earlier blocks the output power.[15]When the Magsafe connector is plugged into a Macbook, the laptoppulls the power line low.[16]The microcontroller in the charger detects this and after exactly one second enables the power output.The laptop then loads the charger information from the Magsafe connector chip.If all is well, the laptopstarts pulling power from the charger and sends a command through the data pin to light the appropriate connector LED.When the Magsafe connector is unplugged from the laptop, the microcontroller detects the loss of current flow and shuts off the power, which also extinguishes the LEDs.You might wonder why the Apple charger has all this complexity. Other laptop chargers simply provide 16 volts and when you plug it in, the computer uses the power. The main reason is for safety, to ensure that power isn't flowing until the connector is firmly attached to the laptop. This minimizes the risk of sparks or arcing while the Magsafe connector is being put into position.Why you shouldn't get a cheap chargerThe Macbook 85W charger costs $79 from Apple, but for $14 you can get a charger on eBay that looks identical. Do you get anything for the extra $65?I opened up an imitation Macbook charger to see how it compares with the genuine charger. From the outside, the charger looks just like an 85W Apple charger except it lacks the Apple name and logo.But looking inside reveals big differences.The photos below show the genuine Apple charger on the left and the imitation on the right. Inside the Apple 85W Macbook charger (left) vs an imitation charger (right). The genuine charger is crammed full of components, while the imitation has fewer parts.The imitation charger has about half the components of the genuine charger and a lot of blank space on the circuit board.While the genuine Apple charger is crammed full of components, the imitation leaves out a lot of filtering and regulation as well as the entire PFC circuit. The transformer in the imitation charger (big yellow rectangle) is much bulkier than in Apple's charger; the higher frequency of Apple's more advanced resonant converter allows a smaller transformer to be used.The circuit board of the Apple 85W Macbook charger (left) compared with an imitation charger (right). The genuine charger has many more components.Flipping the chargers over and looking at the circuit boards shows the much more complex circuitry of the Apple charger.The imitation charger has just one control IC (in the upper left).[17]since the PFC circuit is omitted entirely. In addition, the control circuits are much less complex and the imitation leaves out the ground connection.The imitation charger is actually better quality than I expected, compared to the awfulcounterfeit iPad charger and iPhone charger that I examined.The imitation Macbook charger didn't cut every corner possible and uses a moderately complex circuit.The imitation charger pays attention to safety, using insulating tape and keeping low and high voltages widely separated, except for one dangerous assembly error that can be seen below.The Y capacitor (blue) was installed crooked, so its connection lead from the low-voltage side ended up dangerously close to a pin on the high-voltage side of the optoisolator (black), creating a risk of shock.Safety hazard inside an imitation Macbook charger. The lead of the Y capacitor is too close to the pin of the optoisolator, causing a risk of shock.Problems with Apple's chargersThe ironic thing about the Apple Macbook charger is that despite its complexity and attention to detail, it's not a reliable charger.When I told people I was doing a charger teardown, I rapidly collected a pile of broken chargers from people who had failed chargers.The charger cable is rather flimsy, leading to a class action lawsuit stating that the power adapter dangerously frays, sparks and prematurely fails to work.Apple provides detailed instructions on how to avoid damaging the wire, but a stronger cable would be a better solution.The result is reviews on the Apple website give the charger a dismal 1.5 out of 5 stars.Burn mark inside an 85W Apple Macbook power supply that failed.Macbook chargers also fail due to internal problems.The photos above and below show burn marks inside a failed Apple charger from my collection.[18]I can't tell exactly what went wrong, but something caused a short circuit that burnt up a few components. (The white gunk in the photo is insulating silicone used to mount the board.)Burn marks inside an Apple Macbook charger that malfunctioned.Why Apple's chargers are so expensiveAs you can see, the genuine Apple charger has a much more advanced design than the imitation charger and includes more safety features. However, the genuine charger costs $65 more and I doubt the additional components cost more than $10 to $15[19]. Most of the cost of the charger goes into the healthy profit margin that Apple has on their products. Apple has an estimated 45% profit margin on iPhones[20]and chargers are probably even more profitable.Despite this, I don't recommend saving money with a cheap eBay charger due to the safety risk.ConclusionPeople don't give much thought to what's inside a charger,but a lot of interesting circuitry is crammed inside.The charger uses advanced techniques such as power factor correction and a resonant switching power supply to produce 85 watts of power in a compact, efficient unit.The Macbook charger is an impressive piece of engineering, even if it's not as reliable as you'd hope.On the other hand, cheap no-name chargers cut corners


Welcome to the group! You can connect with other members, ge...


bottom of page