This not important ....

[clint_flick]

Hi

Vodafone VOIP adapter, by whatever name ..........

Ignore the orientation.

But it seems that a capacitor is fitted which may make it polarity conscious.

A pair of wires to 2 and 5,  RD & GN although I cannot assign pin numbers to colour.

Otherwise I believe it is a simple pin 4 & 5 OUT US style;   to  2 & 5 UK style IN.

[Ripshod]

Yeah, polarity is a bygone worry - not necessary these days. The last things that needed the correct polarity were early fax machines. 

These days if any device needs to use the line voltage they have a bridge rectifier on the power circuit's input.

These simple days will soon be gone - glad I got my fibre work up to date. Keep that poster, may be valuable to a museum some day lol

[Jayach]

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@Ripshod wrote:

These days if any device needs to use the line voltage they have a bridge rectifier on the power circuit's input.

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A bridge rectifier converts AC voltage to DC, how does that help with line voltage?

[Cynric]

You connect the battery at the other two points of the diamond, i.e. between the two diodes with the same electron flow direction.

[Ripshod]

Correct. It can be used to rectify AC to DC. Think about what AC is - half positive, half negative. The bridge rectifier (a bridge of diodes) when one input is positive sends positive to the positive output. When the voltage reverses the new positive input still sends positive to the positive output. Not so weird really.

Grab a diagram of a bridge rectifier as a diamond then trace the flows when the input is connected to dc. Reverse that dc and trace it again. Both outputs are the same. 

BOOM! 

[Cynric]

@Ripshod  Mainly BOOM when you get it wrong with a large oil capacitor 🙂

[Ripshod]

Or when PFCs to an induction furnace take exception to a voltage spike. Don't want to stick around to see that. 

[Jayach]

@Ripshod @Cynric 

Yes, I know all that. I think I misunderstood the original comment.

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@Jayach wrote:

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@Ripshod wrote:

These days if any device needs to use the line voltage they have a bridge rectifier on the power circuit's input.

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A bridge rectifier converts AC voltage to DC, how does that help with line voltage?

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I thought you were referring to the telephone line voltage. (as that is what the latter part of the thread has been about) That's why I was confused. I blame it on my age.

[Jayach]

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@Ripshod wrote:

It would be good to revisit in 20 years or so, to mull over the simplicity through moist eyes. 

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I'm not sure I'll be around then, I will be 93, I think I'll have other problems if I'm still here.