Question about simple circuit...

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Externet

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Good day all.

When the switch is on, 10 Amperes flow trough it.
When the switch is turned off, there is arcing between its contacts.



When the switch is on, 10 Amperes flow trough it.
When the switch is turned off, is there arcing between its contacts ?


Same, less, more, no... ?
 

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Hi,

I guess in the given idealistic curcuit the arcing can barely recognized.
Arcing often has to do with inductance, maybe stray inductance.

A purely resistive load does not store any energy, it just dissipates electrical energy into heat.
The given 250V DC are too low to cause/keep an arc with length more than a couple of micrometers.

Klaus
 

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KlausST said:
The given 250V DC are too low to cause/keep an arc with length more than a couple of micrometers.
Click to expand...
That's to establish an arc in free air.
But once an arc is initiated as the contacts open, it takes less than 50V to maintain the arc over a short distance if sufficient current is available, as happens in an arc welder.
 

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I believe, contact arcing can occur at 250V also without circuit inductance. The arc is ignited when the contacts separate and have in fact only micrometer distance.

I agree that stronger arcing is observed with inductive load. 250V/10A DC with purely resistive load is however far above the rating of most smaller switches and relays and can easily destroy it.

Regarding post #1 circuits, the 10 k resistor is directly parallel to a voltage source and can't have any effect besides a small quiescent current.
 

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