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About Laptop Power Supplies
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What was a laptop power supply?
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What factors should be considered when purchasing a laptop power supply?
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How do ich know if a laptop power supply is defective?
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Bottom line
What was a laptop power supply?
The power grid in Germany supplies a voltage of 230 volts. Not every electronic device can be operated with this voltage. Commercially available laptops operate at voltages between 5 and 12 volts. Power supplies convert the incoming voltage into the voltage required to operate the terminal. Each smartphone and notebook has such a power supply so that the battery can be charged. The power supply of a notebook differs only in the design, connectivity and function of a smartphone. A car power supply enables the operation of a notebook while driving. Due to the standardization of cigarette lighters, a special car power supply unit can be used in almost every vehicle.
The power supply via the mains unit can be done in three ways:
- Power supplies with a multi-pin plug and very thick cable produce raw voltages. The required voltage is controlled in the notebook itself
- Power supplies that generate a single voltage have a multi-pole plug in which the poles are connected in parallel.
- The complete regulation of a single raw voltage takes place inside the laptop. These power supplies have thin cables and a two-pin plug. Disadvantage: The notebook generates a lot of heat.
What factors should be considered when purchasing a laptop power supply?
The power connection
If a power supply unit was purchased in Germany, it may not be usable abroad. The reason for this is the respective types of sockets. In case the power supply has to be used abroad, it is possible to operate it via a travel adapter. Some of the power supplies offered already bring such a feature from the house.
The notebook connection plug
Power supplies differ not only on the basis of the available voltages, but also on the notebook connector. Before purchasing the power adapter, check the size and shape of the power connector on the laptop. To be on the safe side, it is worth looking at the product description of the laptop. With the help of the product description, the power supplies can finally be compared with the power connection of the notebook.
Universal power supplies have the advantage that they already come with many different adapters when they are purchased. This enables a flexible use of the power supply and also minimizes the risk of a wrong purchase.
The output power
Each power supply has a maximum output power. This is specified in watts and must be determined on a case-by-case basis using an invoice:
Ampere * Volt = Watt (Power)
The specified number of watts must be compared with that of the laptop. If the values are not matched, there is a risk that the notebook will not start or cannot be charged.
The voltage
A certain voltage is required to ensure trouble-free operation of the laptop. All laptops have a voltage between 18 and 20 volts. A power supply with an output voltage that is too low, such as 16 volts, will not work with the notebook and may even cause damage to the battery. A tolerance limit of 5 percent is permitted in both directions and must not impair the function.
The maximum current in mA should be higher, but not lower than that of the notebook.
The purchase of the laptop power supply must be matched to this number. Fixed voltage power supplies are available for purchase. Too low or too high a voltage can damage the battery or destroy other components inside the device. However, there are power supplies that are designed for universal operation and have a switch to regulate the voltage.
Check for a protective mechanism on the laptop
Many manufacturers make sure that only power supplies from the house can be used with the laptop. The protection mechanism is that universal power supplies are not compatible with the notebook, although all factors such as plug size and voltage have been tested prior to purchase. In such a case, the notebook detects via a pin on the middle part whether it is an original or a third-party power supply.
How do ich know if a laptop power supply is defective?
To detect a defective power supply, you need to know what was the symptoms of a failure. Noise, interference, heat, and other factors indicate a failure. Further information is:
Sudden shutdown
The notebook turns off after battery operation and cannot be recharged or the notebook turns off after a certain period of operation and can only be used again after it has cooled down.
Cause: The laptop is powered by an unsuitable power supply, for example, one that has too little voltage.
Control display
After the power adapter is connected to the laptop, the power supply indicator flashes or does not light up at all.
Cause: The power supply is overloaded. In addition, there may be a defect in the controlling components on the mainboard of the notebook.
Brightness changes
The notebook can detect changes in brightness during operation even though it is connected to the mains.
Cause: If the power settings in the software are set to the default settings, the device may change brightness because the device constantly switches between mains and battery power. This may be due to a loose contact at the power socket or in the power supply cable itself.
Battery is not charging
The control LED does not light up at all or is very weak. The laptop is running properly when connected to the mains, but the battery is not charging.
Cause: The power supply is too weak. In many cases, it is possible to set the required voltage with a switch for a universal power supply. If necessary, the error can be corrected by changing the voltage level.
Weak power supply
A "beep" sound is heard while the power supply is connected to the mains.
Cause: The power supply unit is not yet completely defective, but can fail at any time. The noise is caused by weak solder joints on the capacitors inside. It is recommended to purchase a new AC adapter, as a sudden failure can cause serious damage to the notebook.
Bottom line
There are several factors to consider before purchasing a notebook power supply. The voltage and watt specifications of the notebook as well as the power connection on the device itself are decisive If the notebook has to be transported between the workplace and the place of residence, it is worth purchasing a second power supply. Converters and voltage transformers can be used to scale down higher power sources. All other criteria, such as handling, additional scope of delivery and brand, can be met according to personal preferences and purposes and are not decisive for functional operation.