spark at 5-gang surge protected sockets when plugging in laptop.....?

[151]

hey all!

I have a 5 way plug socket thingy with "surge protection" built in. When I plug my laptop psu (or phone charger) into it and it is already switched on at the wall I often see an spark. It seems to work fine however. Whats the deal?

I read the following but I am skeptical:

"If you are plugging/unplugging under load it means that there is some abrupt energy change causing a spark. Inductors (motors) try to prevent changes in current. So if you unplug one while on it will spark. Capacitors try to prevent changes in voltage. So if you plug something in with a switchmode supply, it will spark as the input capacitors try to quickly charge."

Is this "normal" or expected sometimes? i mean my laptop uses a switched mode psu - I just want to be sure my laptop is in no danger!!

cheers !

[Old and Grunpy]

GRUMBLINGS

[RBM]

If you plug or unplug under a load, there will be a spark

>

[Art Todesco]

Switching power supplies usually draw a large current for a short time when first plugged in. This is the charge the capacitor in the front end of the supply. Some supplies have better inrush circuits than others. The poorer circuits will produce a bigger spark.

[151]

.

so its not likely to damage the PSU then?

[w_tom]

Without or without an inrush current limiter, damage is unlikely. However supplies with an inrush current limiter are even less likely to suffer damage.

Same 'spark' would exist inside a switch. Making a faster 'break or make' would reduce spark's intensity. But power is still applied just as abruptly.