probably nobody will care, but I’m sad at the passing of my microwave. It was born in July of 1983, and died march 24th, 2026. I had bought it used in 1992 and it faithfully served me and my family for many years until today, when the keypad decided to partially quit working. Rest in peace Zappy, you will be missed.
I’m looking for a new keypad but unsurprisingly the parts for this ancient thing are no longer in stock so I doubt I’ll be able to resurrect it without some sort of miracle. I know it’s just an appliance but it still makes me sad to see it go.
No capacitor can hold electricity for even hours. That’s why we use batteries.
Back in my teens I took apart a small tv, and I took the circuit board out and threw it on a shelf in my closet. 6 months later I was cleaning out the closet and accidentally brushed against the board with my hand, and I can say with absolute certainty that they will indeed hold a charge for a very long time even if unplugged.
They absolutely can, that’s why we often put resistors across so they slowly discharge.
The reason we don’t use them as batteries (yet) is their very low energy density. We’d need kgs of capacitors to match a typical phones battery life.
what? capacitors discharge naturally, it’s why there has to be a diode to prevent the flow back to the source of charge.
Sounds like you are talking about the entirety of a small circuit?
If the circuit connects both sides of the capacitor, then it will discharge it. But that means the circuit is discharging the capacitor.
If I am, say, putting a capacitor across neutral and live of an ac cord, then I am charging it. Then if I unplug the cord and connect the live and neutral wires, I would be discharging the capacitor.
But … you don’t connect the wires of your plug. They are floating. If one is held at 300V from the capacitor because that was the voltage at the moment I broke the connection, then it will remain at 300V relative to the other forever.
Floating is the default state of disconnection. If I rip the capacitor straight out of the running machine, it will be floating and will usually keep its charge for years. If your remaining circuit doesn’t contain something that can drain the capacitor, it will stay undrained.
Please promise me you will never open up a power supply.
After months of not plugged in? please.
You are dangerously wrong.
Confidently incorrect, the best kind
There are endless specific warnings about specifically opening microwaves, because this exact thinking is what has gotten hundreds to thousands of people killed over the years.
Specifically microwaves, specifically from feeling safe because they have been sitting in a trash pile or basement for months or years.
It happens comically often, to my knowledge it’s the most common specific cause of death in diy.
That high voltage glass fracturing is gunning for number one nowadays, though I am pretty sure they’re made with old microwave parts.