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Do connectors exist that allow sudden "Pull-apart" whilst conducting high current?

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treez

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  • connector for charger.pdf
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Hi,

All depends on specifications:
Current?
Voltage?
Pin count?

Klaus
 

    T

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Thanks, yes, the above charger in top post is 50V, 3A, and doesnt have the suggested connector that i proposed.

But actually, i have a sneaking feeling, that even though it would be of use...the connector that i propose, in the top post, does not exist anywhere in the world...would you agree?

As we see, the charger of the top post should really have the proposed connector, but does not.....as we know, it is simply not acceptable for a charger to be killed simply by someone unplugging it when loaded....the general public are not electronics engineers, as we know.... as you know, they have no idea that "Unplugging on load" is a charger killer.
 

i have no idea if the plug you suggest exists

i know that safety has to be intentionally designed in
what you propose should be designed into the power converter

plugs can be changed
not so much the insides of the power converter
 
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Thanks, but this cant be completely designed into the converter....but of course i know what you mean...you can stop the PSU being damaged by stuff you put in the PSU to protect it...but the connector surface damage due to the stray L should also be limited with the components i show in the connector itself.
 

maybe that should go in the battery holder?
 
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Thanks yes, but there is still stray inductance in the cable leading to the battery....oh sorry...you mean put the whole connector in the battery holder itself?
 

The whole thread is based on the asumption, that the energy stored in the cable inductance is so large, that the voltage must be clamped to inside the connector to protect it against arcing during disconnect.

Is the idea substantiated by any empirical observations or calculations?
 

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Thanks, this thread is based on the warning by the charger manufacturer that the charger will be damaged by disconnecting the charger whilst its charging. (this warning is highlighted in the top post).

Though yes, also there are concerns for the connector surfaces being damaged. Relays for example always have less lifetime for inductance load current breaking.

I am quite surprised they are saying the charger will be damaged...as surely the stray inductive current would just go through the charger's output caps, and the damaging overvoltage would be at the connector?
 

I would have thought if such a danger existed it would be sensible to add an interlock circuit in the connector. For example a loop between two pins that when broken cuts the supply or engages some other protective measure.

Brian.
 
Hi,

treez said:
this thread is based on the warning by the charger manufacturer that the charger will be damaged by disconnecting the charger whilst its charging. (this warning is highlighted in the top post).
Click to expand...
Just guessing:
If the charger includes series inductors maybe combined with filter capacitors ... then on sudden disconnection the resulting voltage pulse (energy stored in inductor) or ringing may destroy the capacitors or other connected circuitry (like voltage measurement path).

Just an idea:
Maybe install a pushbutton at the connector in a way that when one wants to pull out the connector the button gets pressed and stops charging ... I don't know whether this is mechanically and electrically possible..

Klaus
 
Thanks, yes you are right, if a current source is suddenly no_loaded then its output voltage will shoot up......but usually there is an overvoltage shutdown included to deal with this...so maybe they didnt bother to add this, perhaps.
 

the premise might be a bit ill conceived, a fast pull apart on a charger that has a slow volt loop will cause the o/p volts to go up - this is best countered with a large zener ( 10 x 5W zeners - or TVS ) inside the charger - or a diode to a large cap with a bleeder R across it.

at the connector there is nothing to prevent arc flash and damage to the connector pins - some systems use ( an extra ) short pin inside the connector that breaks first and halts the converter - thereby preventing over volts AND arc flash
 
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