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Another phone charger death - police issue warning

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Puzzled by this. How do you get a lethal shock from the very low voltage needed from a phone charger? Are they saying that somehow, due possibly to poor manufacture, that mains voltage passed through the transformer and rectifiers in the charger? If so, how on earth could such a shock pass through a vital organ (normally the heart) and cause death? Bearing in mind he was lying on the bed so not earthed. There also has to be a return path.

There have been many cases of this just search the web. Evidently, the products just run current all the way thru and there is no bump down to low voltage etc. This is not the first death from faulty phone charger and the one I am thinking of in China I saw in the news was an Apple I-phone. Story disappeared fast!

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So what you sparked saying that this cheap charger causes death is nonsense and we have a conspiracy theory of the highest order? Someone conclude matters please.

On 7/27/2016 at 6:37 PM, aussie11950 said:

There is no electical approval regulation in Thailand that I know of.

Shops can sell any appliance they can make money on.

Its different of course to most developed nations.

The failure of a phone charger can allow the mains voltage to pass to the secondary and to the phone.

As the bed and the human have a large surface area, the capacitance is the return path and can supply enough current to stop the heart.

An ELCB or SAFETY SWITCH would generally detect this loss of return current and trip the switch within 30 milliseconds and save lives

Absolute garbage

On 7/28/2016 at 8:31 AM, DrTuner said:

They chop the DC to pieces, f.ex. 10% duty rate out of 220 is 22V. There might be a transformer component connected to this chopped up line that may further reduce the voltage and provide galvanic isolation. Wikipedia has an article on the buck-boost and flyback converters. In the traditional transforming power supply you'd have the transformer on the AC side followed by a diode bridge.

It's usually easy to see if it's a switching one, the input voltage has a wide range such as 110-220V, simple transformer power sources have a small operating voltage range.

More garbage...show me a step down DC transformer.

4 hours ago, Mudcrab said:

More garbage...show me a step down DC transformer.

Told you there's no need for a transformer component if you don't need galvanic isolation, but as you so kindly asked, I take it you can read schematics:

 

9v-to-3v-step-down-converter-by-lt1073.j

If the input is AC, throw in a rectifier bridge and a cap to make it DC first.

 

If anyone is wondering why the phone chargers sometimes make a high pitched sound, that's a defective inductor component on the output side, the windings are resonating at a primary or harmonic frequency of the DC switching.

On 8/3/2016 at 6:53 AM, DrTuner said:

Told you there's no need for a transformer component if you don't need galvanic isolation, but as you so kindly asked, I take it you can read schematics:

 

9v-to-3v-step-down-converter-by-lt1073.j

If the input is AC, throw in a rectifier bridge and a cap to make it DC first.

 

If anyone is wondering why the phone chargers sometimes make a high pitched sound, that's a defective inductor component on the output side, the windings are resonating at a primary or harmonic frequency of the DC switching.

I certainly recognize a voltage regulator when I see one. But my question was show me a DC voltage transformer...they do not and cannot exist.

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