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A power strip is a combination of electric sockets attached to each other by a cable on a desk, allowing the electrical devices to be powered from one single source of energy.
It is also known as extension box, multi-socket, socket box, and so on. It is used by many devices in powering their batteries. It comes with a circuit breaker in case of a high electric current. The breaker also interrupts the current whenever there is overload or high voltage.
It comes with a switch that can be used to turn it on and off. It also comes with an indicator which can either be a LED indicator or a neon indicator that shows when power is on. The ones that come with power surge protection systems have extra indicators to show the status of the purge system.
Some power strips come with in-built surge protectors. These surge protectors also extend surge suppression for TV, phones, and other devices plugged into the power strip.
Surge suppression in a power strip is provided by metal–oxide varistors. These metal–oxide varistors are like high-speed switches which limit high voltage.
A surge protector is a device that is used to protect electrical devices from high or low voltage by alternating the current circuit. It tries to limit the voltage supplied to an electric device either by blocking or shorting the current to reduce the voltage below a safe option for use.
The blocking is done by making use of inductors which can lead to a sudden change in the current while shorting is done by making use of spark gaps, zener- type semiconductors, discharge tubes, and metal–oxide varistors which begins to conduct current when a particular voltage threshold is reached which lead to a sudden change in voltage.
Although the most effective way is the shorting method, where the electrical lines are shorted together temporarily by using the spark gap or clamped to a target voltage by making use of metal–oxide varistors.
Metal–oxide varistor is the component that is situated in the AV input side of any power supply circuit.
It is a variable resistor that varies resistance in accordance with the voltage applied across it. It is used to protect power strips from high voltage. When a power strip is in use the resistance of the varistor will be high and it will draw little current, however, whenever there is a surge the voltage will rise above the clamping voltage and draw more current which will reduce the surge and protect the power strip.
Energy Saving Features
Power strips also come with energy-saving features; whenever the power strip is switched on and it’s not used for a while it will go on standby mode. This is done through a sensor circuit that will detect the level of power. This particular feature helps in using less power especially when the power strip is not in use.
It saves energy consumption. Some power strips make use of a passive infrared or ultrasonic sound detector to detect if someone is nearby. If it doesn’t detect any motion for a period of time it will shut down all the appliances and devices plugged into the power strip.
Power strips with energy-saving features are under the low voltage directive 2006/95/EC and the EMC directive 2004/108/EC and require a CE mark. CE derived from two French words “conformite europeenne” which means European conformity.
The CE mark means the company of the product confirms its compliance with European Union legislation and such product can be sold in European Economic Area.
Arrangement of Socket in a Power Strip
The socket arrangement of power strips varies which can either be multiple sockets in a power strip or a single socket in a power strip. Although the arrangement of sockets in a power strip varies, it is rare for it to be more than two rows of sockets in one power strip.
However, power strips without surge suppression usually come in a single row but there is some power strip that comes with surge suppression and still comes with a single row of sockets. Surge suppression is either in a single or double row configuration. A cable connects sockets closely together on a power strip. A wall wart transformer connects multiple sockets on a power strip.
There are different electric power circuits that come with a power strip. They are ground wire, a neutral wire, and a live wire. They always come in these three pairs of wire because of situations like lightning where both the life and neutral have high voltage spikes that need to be shortened to the ground.
Although some power strips come with only ground wire and live wire. Without the neutral wire, the power strip will still work perfectly well with all the other accompanying features.
Pros and Cons
- It can come with surge protectors
- It comes with three electric power circuits
- It also has three metal–oxide varistors
- Surge protected power strip should not be used with an UPS.
- Overloading of the power strip is not allowed.
In conclusion, under desk power strips come voltage of 120 v and sometimes with outputs like a USB port. It comes with surge protectors and metal–oxide varistors. Most power strips come with three metal–oxide varistors which are connected between each pair of wires.
It also comes with protection status lights that go off whenever the protective metal–oxide varistors connected to the live wire have failed. However, surge–induced triggering of metal–oxide varistors can damage some devices like an uninterruptible power supply which on a norm sees an overload condition any time the surge is being suppressed.
It is advisable not to connect a surge-protected power strip to an uninterruptible power supply. Although, some power strips make use of indicator–capacitor networks to achieve a similar effect of protecting equipment from high voltage.
This is an alternative to surge protectors especially in situations where the user wants to make use of the uninterruptible power supply with the power strip. Check out amazing products on Amazon.com