Why do surge protectors continue to draw power from wall sockets even if switched off or if nothing's connected to them?
Edit: As others have pointed out, it seems switching them off does stop them from drawing power.
switched off? no. that breaks the circuit, no power, no usage. it's basically the same as unplugging it from the wall. if nothing is connected to them, many surge protectors have a small indicator light that shows the surge protector is on. that's about the only power use being used if nothing is plugged in and drawing power.
you might be confusing turning the surge protector off itself, vs the devices it's connected to- many of which will rather enter a standby mode which still draws some power. (for example, microwave ovens will draw some power continuously so that they're always ready, even if they're not always drawing enough power to cook food.)
A surge protector (and the outlet it's plugged into,) will only draw enough power to meet it's demand; even if the supplied power is potentially greater- for example, computer power supplies. A PC with a 60w power supply will operate quite happily with a 120w power supply.
That’s good to know, so I actually don’t need to physically unplug the power strip to trim down the bill. I’ve been doing it wrong for a while
Surely you thought of this, but a lot of surge protectors have (used to have?) a battery backup for short outages. Keeps the PC on so you can save your data.
Those are not surge protectors, but uninterruptible power supplies- most of which will have a surge protection circuit, mind.
Edit: for comparison, this is a UPS:
It weighs 5 pounds, and is about the size of a shoe box. The batteries don’t provide surge protection- instead those use a circuit to effectively trickle charge and maintain the battery. If normal power is lost, that circuit flips over to discharging the battery.
It didn't used to be this way, but modern power adaptors are required to implement standby power:
In the past, standby power was largely a non-issue for users, electricity providers, manufacturers, and government regulators. In the first decade of the twenty-first century, awareness of the issue grew and it became an important consideration for all parties. Up to the middle of the decade, standby power was often several watts or even tens of watts per appliance. By 2010, regulations were in place in most developed countries restricting standby power of devices sold to one watt (and half that from 2013).
Maybe they're actually listening to us.
Do they draw power when switched off completely???
Do they draw power when switched off completely???
Nope. so that rocker switch physically breaks the connection between the wall socket and whatever is plugged into it's sockets. as far as power consumption goes, it's basically identical to unplugging from the wall.
Maybe they’re actually listening to us.
Do... you know about your cell phone? they don't need to but bugs in surge protectors because we so very handily take the world's greatest spying device with us everywhere we go. willingly. without a second though.
When nothing is connected, the capacitors used to smooth power spikes will leak some current and draw power that way
Surge protectors don’t use capacitors.
They use a variable resistance circuit- usually metal oxide varistors. When the supply is at the correct voltage, it just goes through them. When it’s too high (a surge,) the resistance increases and excess voltage is sent out a fork to ground
Oh! Yeah that makes sense... idk why I thought they mainly used a capacitive circuit. So those varistors must dissipate power in normal operation right?
Side note, if you ever want to get real mad about paying money for something open up a cheap surge protector or power conditioner 😹
Just empty shell with low grade solder and cheap wiring?