Why are we told to unplug mobile phone chargers, rather than just switch them off at the socket?

Question

Why are we told to unplug mobile phone chargers, rather than just switch them off at the socket?

Answer 1

we use a surge protector plug.  you can plug in multiple chargers and just turn off the switch when not in use... this will help the environment in more ways than one...

for starters the indicator light tells you it's on

during a storm your phone is protected meaning less cell phone waiste should it be plugged into a socket during a storm and get destroyed

they come fairly inexpensive, and last a long time.

they can also be used on your electronics that sit on standby when not in use, using up electricity... it's amazing how much energy can be saved if everyone used them and turned them off when not in use.  :)

Answer 2

Transformers are very efficient, but still do heat up & buzz slightly so wasting energy - try touching one & you should be able to feel it, hence they need to be disconnected - either by swithing off or unplugging.

A mobile phone transformer consists of a mains voltage primary coil which is reduced to the phone voltage by the ration of the number of coils on the output side. these coils are connected magneticly. The primary coil still draws current creating heat & noise in the transformer when the phone is unplugged.

Answer 3

If your home has a switch that turns the socket off, it is the same as unplugging. Most North American homes do not have those switches, so one unplugs.

The principle is to disconnect the primary (inut) side of the transformer, not just the output side, because it is having the input side plugged in that accounts for most of the current consumed.

Answer 4

Mine doesn't switch off.  If the charger is plugged in it still draws power.  It is being wasteful.  I unplug any electrical appliance that isn't in use.

Answer 5

because chances are they can either overheat or still draw electricity while not in use wasting energy so I think you should just unplug the charging when not using it to be safe from the two things mentioned above.

Answer 6

It doesn't matter whether you unplug the charger or switch it off at the socket. Both have the same affect.

There is always a minimal amount of power being consumed by any charger that has power supplied to it. Whether it is by the conventional transformer or a switch mode power supply which is becoming more popular due to it's light weight and increased efficiency compared to traditional transformers.

Any properly manufactured charger should be completely safe however, being left powered up while not in use.

There are many safeguards built into even the simple transformer design.

Duane, although correct in his statement that switches fail,

doesn't seem to have the practical knowledge about switch failures.(Or there causes)

In my thirty five years in the electronics industry, I have only seen one or two cases out of thousands where a switch has actually fused to complete the circuit.

One was due to a lightning strike.

The other that I can remember was when someone had tried to test a high horsepower industrial motor on a circuit that was never intended to draw that type of current.

In both cases the damage was immediately evident, and it was obvious that the switch needed replacing.

Most switch failures are not that they will not disconnect, but that there are poor contacts due to oxidation of the contacts, foreign matter preventing the contacts to complete the circuit, or arcing caused by switching on and off high current items over a lengthy period of time.

This question sounds to me that it probably originated from another 'Health and Safety' campaign.

I will say however that if you live in an area which receives regular lightning strikes there a couple of simple precautions that you can take which will cost you no money, but could save you much money and grief.

1)If you know a thunderstorm is heading your way, switch off all  your electrical equipment.

2)Tie a knot in the power cable as close to the plug as possible. This may seem a bit strange, but it is true.

I learned this back in the early 1980's when I was working for a company called Motorola. We had many transmitter/repeater sites to maintain on hilltops and mountaintops which were constantly being struck by lightning and would always cause severe damage. Somebody realized that lightning doesn't like to travel around sharp bends and tried this idea out on a site that was constantly struck by lightning and it worked! Quite often it was only a matter of replacing the power cord rather than a $10,000-$15,000 piece of equipment! This saved the company millions of dollars. (I just hope he was properly rewarded)

Answer 7

Off switches can sometimes fail and with it still plugged in, it could overheat and cause a fire.

Answer 8

I saw an item about this on watchdog a few months ago. Its because they can overheat and catch fire, so please do unplug your one.

Answer 9

Phone chargers are transformers, they take the 120 volts coming from your wall and transform it into 5 or 9 or 12 volts, whatever your phone requires to charge it up.  You should unplug it because the transformer in the charger is constantly sucking voltage from the wall outlet converting it into that lower voltage.  It does this all the time regardless of whether the phone is plugged into it or not.  So basically keep the charger unplugged when you're not using it to save energy and money on your electric bill.

Answer 10

Some phone chargers do not stop drawing energy unless they are taken out of the socket.  In fact, most are that way.  This is called vampire power.  Check out this wiki on how to reduce vampire power: http://greenhome.huddler.com/wiki/how-to...

There's a pretty interesting graphic at the bottom which rates various appliances on the amount of power they continue to draw when switched to off but still plugged in.  Mobile phone chargers are not there but it gives you a bit of an idea how powerful our electric devices are.

Answer 11

Since there isn't anything plugged in to the charger, there is no power being used.  It makes no difference if you unplug them or not, they still draw the same amount of current.

Answer 12

It does the same thing, what they mean is dont leave them switched on when not in use as they use something like 75% of the poer still when they are not even charging.