chargers burned out?

I went to an electronics shop and they told me that I could replace the

5V 0.7A charger of my bluetooth with their 4.5V 0.8A transformer which is the next best thing they have. How would that work? Is it ok to use 4.5V instead of 5V?

The other option is 5V 2A but they said this could potentially damage the bluetooth if not removed after a short period of time from the mains.

Does the Amperage matter ?

Is it DC ?

I'm doubtful about that.

That's rubbish.

The Amps drawn will be determined by the equipment not the power supply.

Graham

On 16 Sep 2006 07:49:29 -0700, in message , "interuser" scribed:

Wall plug-in power supplies are funny beasts, in that they are not well regulated. For the most part, they rely on the load to set the voltage. If you plug in a 5V wall supply and measure its open-circuit voltage, it could be as high as 6.5V or more, and will not regulate to 5V until the proper load is applied. The upshoot of this is that the 5V-2A supply might supply a voltage quite a bit higher than 5V if the load is only 700mA.

The other problem is that the 4.5V supply might not have a high enough voltage to be able to charge the battery in your equipment. To charge a battery, a voltage slightly higher than the battery voltage is required. Voltage too low and the battery does not charge (or may even discharge into the supply - called "backfeed"), voltage too high and the battery gets too much current and is damaged.

I'd try to find the proper charging equipment, if I were you.

yes DC

One more question. I just tried to charge a 2nd brand new cellular battery via the USB computer cable provided and it won't charge (LED goes off after 5min) whereas the one on which the mains charger died seems to charge ok via USB.

Any ideas as to what may be wrong?

Thanks.

If they said that, it means it's unregulated ( voltage varies a bit with actual load ). Without knowing the details of the original charger its impossible to say if that's important or not I'm afraid.

Graham

Was that battery already charged ?

Graham

On 16 Sep 2006 08:43:28 -0700, in message , "interuser" scribed:

Right, like I said in my previous post about unregulated supplies. If you don't exactly match the old equipment, you are shooting dice. If the proper charger is three times as expensive, it probably is regulated, and possibly even has a shut-off function for when the equipment is charged.

First, find out why you blew out your original equipment. Second, find out if you are covered by warranty, as your equipment is new. Third, don't risk damaging your equipment by using the wrong power supply. If you do that, there is no way you will be covered by warranty.

No never charged before. Brand new. And pressing the power on button will not turn on the cellular.

How can I find out without having to pay an electrician to inspect the house? I thought of measuring the voltage (using a voltmeter) at the socket for about 5 mins. If I see any fluctuations then probably the mains supply at home is bad.

Is it possible the socket is problematic somehow?

Strange.

Graham

If you had a *real* problem with your electricity supply I'd expect you'd have noticed by now.

I suspect either simply bad luck or poor design.

Many Chinese outfits think the European supply is actually 230V ( because a regulation says so ) but certain places like the UK have traditionally been 240V ( maybe Cyprus too ? ) and it hasn't actually changed. The 230V is purely 'nominal'. I can regularly read 252V here for example and it makes some AC adapters hum like crazy ( clearly badly designed not taking into account the true wall socket voltage ) !

Graham

240V

true

That makes more sense. Here the voltage is 240V and I guess it will not be uncommon to go over 240V. I guess the manufacturers of devices destined for Cyprus have this in mind and that's why I never had this problem in the past with other devices. These chargers have input range 100-240V but it is possible they are not tolerant to fluctuations (although they were destined for Australia

- among others - where the current is 240V ).

One question remains though: is it possible the devices (cell phone and bluetooth headset) were damaged or the damage stopped at the chargers? I can tell the cell seems to work ok (apart for not beeing able to charge a brand new battery)

Let us know the complete specification of the chargers, voltage, FREQUENCY, etc. Copy from the labels.

"Eeyore" wrote in message news: snipped-for-privacy@REMOVETHIS.hotmail.com...

If these are 60 cycle chargers they will die on 50 cycle power.

On 16 Sep 2006 10:20:41 -0700, in message , "interuser" scribed:

That's a good question. I guess there's a reason electricians are regarded as skilled craftsmen.

cell phone: input : 100-240V 0.2A 50-60Hz Output: 5VDC 1A LPS

bluetooth headset: input : 100-240V 0.15A 50-60Hz Output: 5VDC 0.7A

I am not sure if they were not designed for Cyprus (240V ) Maybe I should seek the fault at my mains But then again why other cell chargers and PC power supplies do not blow? Is it possible the specific socket is faulty?

You can buy a DMM for a lot less than a house call.