Topic: Mobile phone charger fuse (Read 6605 times)

amba · « **on:** 06 November 2007, 16:03:01 »

Can anybody offer some advise...use a parrot hands free system through the stereo which is fine,but bit annoying when the battery on my nokia 6300 goes flat.So decided to buy a nokia plug in phone charger via the ciggy lighter.When I plug this in the fuse in the socket immediatly blew .Tried to remove the fuse but as a sealed unit went back to the shop..who said my problem so hard luck !!!Found a different type in Halfords which fitted the phone and seemed to have a removable/replaceable fuse.First time I tried it the fuse again blew..removed and found a glass type fuse which we think was about 2 amps.Went to local spares shop and bought pack of 5 amp replacements and tried again..result the same ..blewn fuse.
Thought too much power coming from ciggy lighter so bought a seperate dedicated female plug ciggy unit with a wired connection which I have carefully connected to a ignition fed supply via the glove box interior light.Feeling quite sure all would now be ok plugged the phone socket in and again the fuse blew.
As I am now puzzled why can anybody advise..female socket has power to it as indicated by a test light and will light a hand held flood light..is the fuse in the socket too small but would a larger fuse run the risk of damaging the phone??the female ciggy socket has max6.5amps on the side so assume my 5 amp fuses were about right

Marks DTM Calib · « **Reply #1 on:** 06 November 2007, 17:50:55 »

A key point here is that a fuse wont blow for no reason and more important is that they are designed to protect the supply and not the equipment because if the fuse is blowing is the equipment causing it.

So in this case it wont be the cigerette lighter at fault but more likely a problem with the the phone or charger.

Putting a larger fuse in does nothing more than increase the risk of serious damage occuring and is not something I would recommend.

Plus given that the fuse as 2 amp thats a max of 24Watts available to charge the phone which is a hell of a lot.

amba · « **Reply #2 on:** 06 November 2007, 17:58:02 »

fully understand your point,but the confusion is that 2 different ciggy phone chargers are doing the same thing even with no phone connected at other end,just into socket,and moreover they are 2 different sockets.
Power is still at the ciggy socket as will illuminate a hand held light without anything blowing?

Golfbuddy · « **Reply #3 on:** 07 November 2007, 07:55:03 »

Quote

fully understand your point,but the confusion is that 2 different ciggy phone chargers are doing the same thing even with no phone connected at other end,just into socket,and moreover they are 2 different sockets.
Power is still at the ciggy socket as will illuminate a hand held light without anything blowing?

What rating is the hand held lamp?

amba · « **Reply #4 on:** 07 November 2007, 08:24:11 »

On the plug it says 12 volt 55 watt..cheapy Halfords hand held light with red shade cover..this can be plugged into the front/rear ciggy lighters or the new extension socket I have wired in and works every time...the phone charger blows fuse the moment it is plugged in..strange thing is this is second phone charger so cant see 2 different chargers having same fault??

Marks DTM Calib · « **Reply #5 on:** 07 November 2007, 10:05:57 »

Do you have a volt meter available?

Golfbuddy · « **Reply #6 on:** 07 November 2007, 11:28:15 »

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On the plug it says 12 volt 55 watt..cheapy Halfords hand held light with red shade cover..this can be plugged into the front/rear ciggy lighters or the new extension socket I have wired in and works every time...the phone charger blows fuse the moment it is plugged in..strange thing is this is second phone charger so cant see 2 different chargers having same fault??

Which, by my 'O' level physics tells me that this runs at 4.58 amps which is not dissimilar to the fuse which blew. This would suggest to me that, as MarksDTM said, it is a problem with the charger and not the circuit.

Does my logic make sense?

x25xe · « **Reply #7 on:** 07 November 2007, 13:32:10 »

Yes, it does and your calculation is spot on.

Marks DTM Calib · « **Reply #8 on:** 07 November 2007, 13:46:32 »

Quote

Quote
On the plug it says 12 volt 55 watt..cheapy Halfords hand held light with red shade cover..this can be plugged into the front/rear ciggy lighters or the new extension socket I have wired in and works every time...the phone charger blows fuse the moment it is plugged in..strange thing is this is second phone charger so cant see 2 different chargers having same fault??

Which, by my 'O' level physics tells me that this runs at 4.58 amps which is not dissimilar to the fuse which blew. This would suggest to me that, as MarksDTM said, it is a problem with the charger and not the circuit.

Does my logic make sense?

To some extent but, the fuse is in the charger.......the ciggy lighter fuse is around the 20A mark.

If you can measure voltage then stick the pos probe on the centre contact of the ciggy lighter socket and the neg on the metal surround......post teh volateg result including if its + or -

Golfbuddy · « **Reply #9 on:** 07 November 2007, 16:00:38 »

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Yes, it does and your calculation is spot on.

25 Years later and the mind is still sharp as a tack.

[smiley=2vrolijk_08.gif] [smiley=2vrolijk_08.gif] [smiley=2vrolijk_08.gif]

amba · « **Reply #10 on:** 07 November 2007, 16:33:43 »

Hope this makes sense but with ignition on and engine not running the voltage is +11.40 volts,but bearing in mind that the retro fit ciggy lighter socket is direct wired from the glove box interior ligh..didn,t realise that it only gives power when glove box flap open..so looks like i will need to find another 12volt ignition feed without pulling the dash appart

Marks DTM Calib · « **Reply #11 on:** 07 November 2007, 16:48:20 »

Well, you have just proven with that measurement that the ciggy lighter socket is fine.

Is any part of the phone metal and are there any other connections to the phone when you do this test?

amba · « **Reply #12 on:** 07 November 2007, 17:05:33 »

Assuming I am getting 12 volts at the ciggy unit..why would it then follow that 2 different mobile phone chargers by different manufactures are causing this problem.Even with no phone connected and the charger pushed into the socket the fuse instantly blows..just tried it again with another 2 amp fuse and it went

Andy B · « **Reply #13 on:** 07 November 2007, 17:53:38 »

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Hope this makes sense but with ignition on and engine not running the voltage is +11.40 volts,but bearing in mind that the retro fit ciggy lighter socket is direct wired from the glove box interior ligh..didn,t realise that it only gives power when glove box flap open..so looks like i will need to find another 12volt ignition feed without pulling the dash appart

:-? Surely the glove box feed is ignition live, and it earths/grounds when you open the glove box door. I'm not going out in the p***ing rain to check but I'm sure I'm right. My wife's Astra G's phone cradle was fed via the glove box live - although not tested I'm sure the previous owner wouldn't have had the glovebox open to use the phone! :-/

amba · « **Reply #14 on:** 07 November 2007, 20:42:46 »

Well I am sorry to say but the plot thickens???wife has come home from work and just to see if I am going crazy tried the phone charger and phone in the ciggy lighter in her car ..renault clit...and you guessed it ..worked perfectly and the fuse didn,t blow and charges as it should.
So here seems to be the problem..either the permenant back or front vauxhall ciggy lighter..the retro fit ciggy socket wired from the glove box live(??) feed..all cause the fuse to blow in the phone charger.....plug the same charger in a different car and it works perfectly.
Do omegas have more power than any other car..unsure what to try now ..perhaps i should buy a renault..no don,t think so !!!

Entwood · « **Reply #15 on:** 07 November 2007, 20:43:07 »

daft question ... has the retro fitted ciggy lighter been put in the "wrong" way round ?? For a light it won't matter s +ve/-ve matter not ... but your charger will have a solid state step down transformer in it, so may well short out if connected "wrongly"

I would do a bit if checking with a meter to check polarity

amba · « **Reply #16 on:** 07 November 2007, 20:59:57 »

Thanks entwood.

I think you may have solved my problem ???the lead with the retro ciggy lighter had a plug on the end which i decided to cut of revealing a red and black wire.....if my memeory is correct i connected the red wire to the brown wire on the courtesy light plug...then connected the black lead on ciggy wire to the black lead on the light wire....will have a closer look again in the morning but your theory does sound logical.....would it be possible for vauxhall to have the brown lead as earth and the black lead as live as from earlier advise it appears that the glove box loght has a permenant live and a switched earth so if that is the case should i connect the red ciggy wire to the live feed from the light and pick up a body work earth?

Andrew

CaptainZok · « **Reply #17 on:** 07 November 2007, 21:10:08 »

Check the polarity of the socket, if it's reverse polarity and the chargers got a diode fitted to prevent reverse connection it will blow the fuse every time.

TheBoy · « **Reply #18 on:** 07 November 2007, 21:18:01 »

But the proper ciggy lighters should be wired correctly

TheBoy · « **Reply #19 on:** 07 November 2007, 21:18:37 »

Or just charge your phone at home

amba · « **Reply #20 on:** 07 November 2007, 21:49:44 »

Thinking for all the trouble might be worth buying a spare phone battery,just does seem strange though why it works in one car and not another...will have a look at the polarity issue in morning and see where that goes...still unsure why it won,t even light charger tell tale light in standard ciggy socket.
Just for info how would i check which feed from the retro socket has the live assuming it isn,t as simple as red/live..black /earth?

Andy B · « **Reply #21 on:** 07 November 2007, 23:03:30 »

Quote

.....would it be possible for vauxhall to have the brown lead as earth and the black lead as live as from earlier advise it appears that the glove box loght has a permenant live and a switched earth so if that is the case should i connect the red ciggy wire to the live feed from the light and pick up a body work earth?

Andrew

That's it. Vauxhall's earth/ground/zero volts/whatever you want to call it is normally brown, lives can be red or can be black for ignition live - look at your courtesy lamp.

Kevin Wood · « **Reply #22 on:** 08 November 2007, 13:56:24 »

Could be that someone has had the main lighter socket out at some point and connected it up wrongly too. Or that once the charger had been plugged into a reversed socket it had blown the internal electronics and it's now shorted internally anyway, so it'll blow the fuse regardless.

Kevin

Marks DTM Calib · « **Reply #23 on:** 08 November 2007, 14:27:53 »

Quote

Could be that someone has had the main lighter socket out at some point and connected it up wrongly too. Or that once the charger had been plugged into a reversed socket it had blown the internal electronics and it's now shorted internally anyway, so it'll blow the fuse regardless.

Kevin

Hence the test I requested including the polarity check......

Kevin Wood · « **Reply #24 on:** 08 November 2007, 17:11:15 »

Quote

Quote
Could be that someone has had the main lighter socket out at some point and connected it up wrongly too. Or that once the charger had been plugged into a reversed socket it had blown the internal electronics and it's now shorted internally anyway, so it'll blow the fuse regardless.

Kevin

Hence the test I requested including the polarity check......

Yes, which didn't show a problem, oddly, and the problem existed before the socket was fitted to the glovebox light :-/

Worth double checking the polarity of the main lighter socket in the car?

Kevin

amba · « **Reply #25 on:** 08 November 2007, 21:13:19 »

Thanks for advise guys..how do i check the polarity??I have not had time today to check if the glove box wiring is brown/eart black /live..as was suggested,so will have a look in morning..will put a test light on both wires on the VX plug from glove box light and try and work out current,as am suspecting the advise of earlier.
Strange thing is also neither fag lighter will stay in when pushed so expect fault with those..just as well i dont smoke???but am now thinking that is why the VX ciggy lighter was also blowing fuse,but as light not polarity sensitive would not stop that from working..so how do i check their polarity ??

CaptainZok · « **Reply #26 on:** 08 November 2007, 21:41:33 »

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Thanks for advise guys..how do i check the polarity??I have not had time today to check if the glove box wiring is brown/eart black /live..as was suggested,so will have a look in morning..will put a test light on both wires on the VX plug from glove box light and try and work out current,as am suspecting the advise of earlier.
Strange thing is also neither fag lighter will stay in when pushed so expect fault with those..just as well i dont smoke???but am now thinking that is why the VX ciggy lighter was also blowing fuse,but as light not polarity sensitive would not stop that from working..so how do i check their polarity ??

With a test lamp go from centre of cig lighter to a known body earth, if polarity is correct it will light.
If it doesn't try edge connection of cig lighter to body earth, if it lights polarity of cig lighter is reversed.

amba · « **Reply #27 on:** 08 November 2007, 22:35:29 »

Thanks CaptainZok..have got a test lamp probe so will have a good look in morning and post results for info.assuking the original VX ciggy lighter at back and front are incorrectly wired which could be the case as neither lighter works and phone charger blows fuse..it is only hand held light which works..but think Entwood has pointed me straight on why that is..how do i correctly rewire the VX ciggy sockets as thought they had factory plug in them?

CaptainZok · « **Reply #28 on:** 08 November 2007, 23:03:51 »

I think its possible to connect the cig lighter plug the wrong way round and reverse polarity.

Entwood · « **Reply #29 on:** 08 November 2007, 23:23:42 »

amba ... a small, cheap multi-meter is invaluable for checking polarity and/or circuit continuity, as well as many other things .. they are now so cheap no-one should be without one ...

eg ..

http://www.maplin.co.uk/module.aspx?ModuleNo=37279&doy=8m11

less than £6 !!!

amba · « **Reply #30 on:** 09 November 2007, 07:42:00 »

Thanks Entwood for info..I will take a trip to our local Maplins today and buy one...for info what is the setting on the dial for 12 volt as when looked at picture couldn,t see a 12 volt marked?

Golfbuddy · « **Reply #31 on:** 09 November 2007, 08:12:39 »

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amba ... a small, cheap multi-meter is invaluable for checking polarity and/or circuit continuity, as well as many other things .. they are now so cheap no-one should be without one ...

eg ..

http://www.maplin.co.uk/module.aspx?ModuleNo=37279&doy=8m11

less than £6 !!!

I've seen these from various sources. Are they any good? If so, what's the difference between one of these and one costing anything from 5 to 50 times the cost?

Entwood · « **Reply #32 on:** 09 November 2007, 10:01:35 »

I don't, personally, use that one, so cannot describe it's operation.. mine does other stuff as well, it is used more for computor repairs than vehicle diagnosis, but is capable of both !! ... I was merely pointing out how cheaply they can be obtained.

Most do not select a specific voltage .... you select a "range" 1-6, 6-20, 20-50 or something similar. as well as a "type" AC or DC . To diagnose vehicle stuff select the appropriate range .. in the above example 6-20 DC would seem ok.

The one I linked to APPEARS to have 5 DC Volt ranges top left but I can't quite read the numbers

When choosing a range ALWAYS choose a high range and work down - saves blowing fuses !

With the range/type selected check the device ... you will read the "no load" voltage at the points .. a - in front usually means the polarity is incorrect, either you have the probes in the wrong place or the wiring is wrong !!

The more expensive devices usually a) do more ranges/operations, b) have better protection built in, c) are more accurate, d) are easier to read (size of screen/back lit etc) e) fancy makers name ?

You DO NOT need to be an electrician/rocket scientist/genius to use one .. common sense and a modicum of care will enable you to check/diagnose minor faults ... as well as ensuring the local idiot does not rip you off with mumbo jumbo.

just my 2.7 p's worth (inc VAT)

Golfbuddy · « **Reply #33 on:** 09 November 2007, 12:29:20 »

I agree Entwood. I've 'borrowed' one from work and have used it quite often. I really could do with some lessons to get the best out of it, but it is amazing how often you can find a use for it.

Entwood · « **Reply #34 on:** 09 November 2007, 12:45:40 »

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I agree Entwood. I've 'borrowed' one from work and have used it quite often. I really could do with some lessons to get the best out of it, but it is amazing how often you can find a use for it.

If you were REALLY bored you could get hold of this from maplins ...

http://www.maplin.co.uk/module.aspx?ModuleNo=787&doy=9m11

or browse the million+ links under

http://www.google.co.uk/search?hl=en&q=using+multimeters&btnG=Google+Search&meta=

Enjoy .....

Golfbuddy · « **Reply #35 on:** 09 November 2007, 14:44:54 »

Quote

Quote
I agree Entwood. I've 'borrowed' one from work and have used it quite often. I really could do with some lessons to get the best out of it, but it is amazing how often you can find a use for it.

If you were REALLY bored you could get hold of this from maplins ...

http://www.maplin.co.uk/module.aspx?ModuleNo=787&doy=9m11

or browse the million+ links under

http://www.google.co.uk/search?hl=en&q=using+multimeters&btnG=Google+Search&meta=

Enjoy .....

Cheers. A bit of light reading for the weekend.

Kevin Wood · « **Reply #36 on:** 09 November 2007, 19:59:59 »

I've just noticed these: http://www.maplin.co.uk/module.aspx?ModuleNo=217881&doy=9m11

Will have to get one of those. Looks very handy.

Kevin

Entwood · « **Reply #37 on:** 09 November 2007, 20:31:56 »

Sparingly useful in a very limited way IMHO ... will tell you if a fuse socket is pulling high current .. you know that when the fuses blow !!!!

Danger is ... whilst running the test the meter/fault is now "un-fused" and damage to wiring could be caused ... fuses blow for a reason.

If a fuse holder has muliple inputs I prefer to check each one in Amps setting with the fuse in place, this will show current in each circuit .. time consuming but effective.

If the holder has a single input then it is usually a wiring fault, as the circuit has a lot of redundancy built in, and high current circuits go through relays for that reason.

Kevin Wood · « **Reply #38 on:** 09 November 2007, 23:32:05 »

I think the original fuse plugs into the side of the tool thus staying in circuit.

I just often wonder how much current circuits are pulling. Not that useful in tracking down a short, I agree, but a slow battery drain could be identified easily.

Just looked like a nice gadget

Kevin

CaptainZok · « **Reply #39 on:** 09 November 2007, 23:59:59 »

An easy way to break into a circuit to check current drawn.
More useful for measurement than fault finding i would have thought.

Golfbuddy · « **Reply #40 on:** 11 November 2007, 00:29:48 »

Surely, when testing the amount of current a circuit is drawing, the fuse would need to be removed as the meter needs to be connected in series. If the fuse was left in and the meter applied, this would be wired in parallel and the test wouldn't work.

I am only going by what I have read but this makes sense to me. The meter featured above would perform just that function by breaking the circuit and thus being fitted in series in the circuit?

amba · « **Reply #41 on:** 12 November 2007, 15:46:10 »

Just a quick update as have now resolved the problems partially...after much head scratching have established the vx use black cable colours as live feed..so have now managed to get my phone charger working by plugging into the retro fit ciggy lighter wired into the rear vx fit ciggy lighter cables...it seems that the black feed is + and the brown -. Only thing I cannot get to work is the vx ciggy lighters as hve found that the plug cannot be connected incorrectly due to its shape..but will not worry about that as dont smoke and nor will anybody else who is in my car..thanks for everybodies help/advise and patienec with a electrical novice..atleast I won,t get a flat mobile phone battery again..only trouble is work can now also find me ?

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Author Topic: Mobile phone charger fuse (Read 6605 times)