What happens if I supply a higher voltage than the rated voltage of my jack?

Question

I want to replace the original jack from my notebook with a new one since it is broken (and I would like to avoid to replace it with the same as the original). The original AC adapter supplies 19V and a bit less than 3Amp. However I can't find on Internet a DC jack (for pannel-mounting use) whose rated voltage is 19 V. All I find are 12V DC / 3Amp MAX jacks.

So what would happen if I use my AC Adapter with that new power DC jack (so 12V 3Amp) ? Will it overheat or is it safe?

Thanks (and sorry if that's a duplicate).

score 3 · Answer 1 · answered Nov 26 '14 at 00:19

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The jacks on DigiKey are rated for 24 V: http://www.digikey.com/product-detail/en/PJ-005A/CP-5-ND/165838

I would not hesitate to use any DC barrel plug at 19V, because that's just not much voltage. Unless it's a really marginal design, it will be OK.

answered Nov 26 '14 at 00:19

markrages

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Thank you for the link. I didn't know that website but well .. since I live in Europe, shipping costs are really expensive (18euros shipping costs for a 2euros jack...). – Desura Nov 26 '14 at 15:11
Anyway, if I use a jack with a higher rated voltage than what the AC adapter supplies, is it more safe ? – Desura Nov 26 '14 at 16:25
Theoretically it is more safe, but safety isn't the issue at these low voltages. – markrages Nov 26 '14 at 17:08
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**Current** rating is what governs whether overheating is a risk. – Spehro Pefhany Nov 26 '14 at 19:08
Ok thanks, I understand. So what is the voltage rating about ? – Desura Nov 27 '14 at 21:12

score 2 · Answer 2 · answered Nov 25 '14 at 23:31

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The voltage a connector is rated for represents the breakdown voltage of the dielectric or insulator; if it is violated then arcing may occur inside the connector itself, and as such presents a severe fire hazard. I strongly recommend that you find a properly rated connector.

answered Nov 25 '14 at 23:31

Ignacio Vazquez-Abrams

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The insulator breakdown voltage is usually much higher than the rated voltage, to give a safety margin. [Dielectric breakdown voltage of air](https://en.wikipedia.org/wiki/Dielectric_strength#Breakdown_field_strength) is ~3 kV/mm, and of wire insulators even higher. So given the distances and insulation thickness *usually* used in DC jacks, adding 7 V will not cause dielectric breakdown. – tanius Dec 11 '15 at 13:46

Kamil · Answer 3 · 2014-11-26T00:24:41.620

I agree with Ignacio, do not use 12V connector with 19V because 19 is more than 12.

At such low voltage probably nothing will happen, but you don't know why it is rated for 12V. Maybe insulation can handle much more, but if you overrate it by more than 50% - you may expect some undesireable effects (including fire, corrosion, changing insulation mechanical or electrical properties).

I would suggest to use Lenovo socket and plug from T43/T60/T61 series laptop. It is well designed and hard to break. Best power socked I ever saw in any laptop. I never had problems with power connector in any ThinkPad (I was stomping on cord many times, pulling it accidently etc.). It looks like this:

enter image description here

Notice that this connector is not supposed to be soldered to board. In my laptop - this connector is surrounded by some rubber and it moves with plug. It is for motherboard protection. In low cost laptops power connectors are soldered directly to board and if you pull cord accidently - you can break whole motherboard.

For plug - just replace whole cable in your power supply. There are cheap cables like this on ebay:

enter image description here

image source: ebay auction link

Those connectors are NOT hard to break. I have had to repair a lot of them over the years. — Grant, Nov 26 '14 at 04:36

What happens if I supply a higher voltage than the rated voltage of my jack?

3 Answers3