3 ms·

This is because your socket lacks grounding. Your laptop's body is normally connected to ground and both power supply lines are also connected to it via two ca

This is because your socket lacks grounding. Your laptop's body is normally connected to ground and both power supply lines are also connected to it via two capaciators. No actual current is driven through it but it does have an effective voltage of ~110V on it unless it is actually grounded. You can feel that but it should be harmless. This applies to most electric appliances.

slau 3y ago
Not the socket’s fault; it’s the charger. My MBP 90W charger doesn’t have a grounding pin. The 60W doesn’t have a grounding pin. They have the hardware to be grounded (the metal T stub on which you attach the local plug), but they don’t come with the extended wire by default which has the grounding pin for the outlet. In actuality, the reason you feel the tingle is because the case is effectively grounded to the neutral pin. The three phases are joined together at the transformer to create a cheap neutral, but because the load on all three phases are slightly out of phase, our body can feel the handful of mV being leaked.
- vundercind 3y ago
  I have an older (USB-A plug) tiny, official iPhone charger brick of that fold-out-two-blade sort which has become either terrifying or hilarious, depending on your temperament, by having whatever connects the two blades break. If you're not paying attention, it's easy to extend only one of the blades... I've not attempted to charge with only the hot-wire blade extended, but I cannot imagine anything good would happen.
  - calini 3y ago
    I really expected a 3rd party company to be producing 3-pronged versions of that adapter. In the UK the ground pin is a requirement as sockets will not fully open up the other two before the ground pin is inserted, and Apple's UK adapter has a metal ground pin, BUT still it's not connected to the 3rd internal prong of the charger. The extension cables that you can still buy separately, and that used to come free in 2012-2015 MacBooks have the 3rd prong, hence are grounded. WHY, APPLE?

slau 3y ago

Not the socket’s fault; it’s the charger. My MBP 90W charger doesn’t have a grounding pin. The 60W doesn’t have a grounding pin. They have the hardware to be grounded (the metal T stub on which you attach the local plug), but they don’t come with the extended wire by default which has the grounding pin for the outlet. In actuality, the reason you feel the tingle is because the case is effectively grounded to the neutral pin. The three phases are joined together at the transformer to create a cheap neutral, but because the load on all three phases are slightly out of phase, our body can feel the handful of mV being leaked.

vundercind 3y ago
I have an older (USB-A plug) tiny, official iPhone charger brick of that fold-out-two-blade sort which has become either terrifying or hilarious, depending on your temperament, by having whatever connects the two blades break. If you're not paying attention, it's easy to extend only one of the blades... I've not attempted to charge with only the hot-wire blade extended, but I cannot imagine anything good would happen.
- calini 3y ago
  I really expected a 3rd party company to be producing 3-pronged versions of that adapter. In the UK the ground pin is a requirement as sockets will not fully open up the other two before the ground pin is inserted, and Apple's UK adapter has a metal ground pin, BUT still it's not connected to the 3rd internal prong of the charger. The extension cables that you can still buy separately, and that used to come free in 2012-2015 MacBooks have the 3rd prong, hence are grounded. WHY, APPLE?