Also why can we restart PCs since this contradicts this recommendation?
In: Technology
You can think of electronics having some energy still in the circuits. Imaging letting off the gas in your car, it doesn’t stop immediately. You the to the the circuit come to a “complete stop” before turning it back on or some of the messy settings that you are trying to wipe clean could still be saved.
When you restart a pc it doesn’t immediately turn back on again. The waiting is to let lingering electricity dissipate.
Nobody really addressed the restarting a PC part. When you tell Windows to restart, the computer itself never really shuts down. The hardware stays powered up, and just goes through the boot process again. All of the physical components are still on. That’s why sometimes a tech, or that computer savvy family member, will tell you to specifically do one or the other. Turning it off and waiting a few seconds does exactly the same as what the others have said: allows the capacitors to discharge.
Most electronics contain capacitors. Capacitors act like little buffers to even out current in a system. A bit like having a header tank in a plumbing system. Think of them like tiny batteries that are constantly charging and discharging.
When you turn off an item, the charge in the capacitors doesn’t go away straight away. You have to wait for a few seconds to allow it yo dissipate. The charge can be enough to mean that certain buffers or bits of memory aren’t properly reset, so without waiting, the restart alone doesn’t always fix it.
For computers, it’s a nonsense.
All computers start by reading the data at memory address 0, which then immediately clears the rest of memory and initialises the machine’s hardware, peripherals and starts the operating system.
“Rebooting” is literally just running that code at memory address 0 again.
For other devices, it “might” make a difference – power is sometimes still stored in the circuits enough to keep running so it doesn’t fully reset things. I have a clock that can survive about 10-15 seconds without any power and still retain all the time and alarms, for instance.
But for computers, it makes no difference whatsoever. Whether you start at 0 by asking it to restart, or start at 0 by turning it off, it makes no difference. (P.S. rebooting a machine to “fix it” is a crock of shit).
Two different answers depending on device.
1) For a modem, or something you want to “reset”, you need to wait for the internal electrical charge stored in something called capacitors to go away. These capacitors hold the charge that causes the lights on some devices to stay on after you turn it off. Just like those lights didn’t turn off, the buggy part of the device might not be off yet.
2) For many devices rapidly “power cycling” the device will damage it. When a device is turned on, the inrush of electricity (called the “inrush current”) is difficult to manage from a circuit design perspective. The inrush typically always causes wear to electrical components.
But for a quick off/on cycle things are more complex. Many circuit components want heaps of power while starting up, and compete with other parts to get the electricity. Parts of the device supplying and regulating the power struggle to keep up with the demand at startup. It comes together in a orchestrated sequence that the electrical engineer planned. If however not everything was discharged from the previous cycle, the startup orchestration is off because something was not draining as much power as expected, when expected. Leaving the device of for say 20 seconds is a good way to avoid this.
NB:There are some other niche factors as well that make rapid on off cycles bad for specific types of devices, including cooling concerns for parts that should not start warm and moving parts to return to a ‘home position’ before the next run.
It’s so you can “let the bad stuff out.” That’s literally how a tech explained it to my mom lol
Most electronics have shut down procedures, and waiting 30 seconds gives them time to perform this action. These procedures ensure the next start up can occur without issue.
If you’ve ever experienced a power outage on a device, and it restarted once the power was restored, usually a message appears indicating the device was not shut down properly.
I do want to take a moment to address the common “capacitor” answer, because it’s worth discussing for a different reason.
Most electronics today use capacitors to ensure a constant current and do not store so much as to require wait times to discharge. Once a device is powered off, a capacitor’s discharge is instantaneous.
That is, if there’s a load applied during a shut down. Some electronic devices will actually retain the voltage when the device is powered down as this can help increase boot times.
Where a capacitor’s discharge time may be necessary are internal power supplies. The capacitors used vary depending on the wattage of the unit, and in some cases, can take time to discharge if the unit loses power if they’re designed to do so.
However, many of today’s power supplies also retain a capacitor’s charge in order to regulate the “infinite current spike” when power is applied to the unit. This is why it is absolutely necessary to discharge all capacitors when working on them just to ensure they don’t surprise you with a nasty shock.
Ironically, some power supplies can now be managed through software, which can become part of the shut down process and why it’s recommended we wait to restart them.
Its like a hose or a tap thats been sitting too long. Gotta let all the stagnant electricity out or the device could get sick
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