UPS Uninterruptible Power Supply: The “Power Bodyguard” at Home

Have you ever been in the middle of a gaming session or working on your homework when suddenly the power goes out, erasing all your progress? That's when the UPS (Uninterruptible Power Supply) steps in like a “power bodyguard” at home, protecting your devices at crucial moments! Let's explain how it works in the simplest terms possible, with some easy-to-understand illustrations.

1. What Does a UPS Look Like?

First, let's take a look at what a UPS looks like. It's usually a square “box” with a power switch and indicator lights on top, and various ports on the sides for connecting devices like computers and routers, just like the diagram below.

2. The “Secret Weapon” of a UPS: The Battery

Why can a UPS keep supplying power during a blackout? The key lies in its built-in battery, which is its “secret weapon.” When the power is normal, the UPS acts like a diligent  little housekeeper”. It delivers the mains electricity (the regular power supply at home) to your devices while also charging its battery, just like charging a mobile phone to store electrical energy. It's like saving money in a piggy bank, which can be used for emergencies when the power goes out.

3. What Happens the Moment the Power Goes Out?

The moment the power suddenly goes out is when the UPS really shows its worth! Its “eyes” (the detection circuit) can instantly sense the power outage and immediately activate its “emergency plan” — it brings out the pre-charged battery to “save the day,” taking over from the mains electricity to keep powering your devices. The transition from the power outage to battery-powered supply is so quick that your computer doesn't even notice, as if the power was never interrupted!

Let's take a look at this process with the simple flowchart below:

4. Two “Working Modes” of a UPS

There are two common working modes for UPS, just like people have different work states.

Online UPS: This type of UPS is like a “super bodyguard” on standby 24/7. Whether there's a power outage or not, it “processes” the mains electricity (rectifies and inverts it) before outputting it to the devices. The advantage of this is that even if the voltage of the mains electricity is unstable or there is interference, the electricity after its processing is very “clean” and “stable,” providing better protection for the devices. However, it's relatively more expensive.

Standby UPS: This is an “economical bodyguard.” When the mains electricity is normal, it delivers the electricity “as is” to the devices. It only switches to battery power when it detects a power outage. It's more affordable, but the switching time might be a little longer compared to the online UPS. Still, it's sufficient for ordinary household devices.

5. The “Battery Limit” of a UPS

The battery power of a UPS isn't endless; it has a “battery limit.” Generally, a UPS can only last for a few minutes to dozens of minutes. The exact duration depends on its battery capacity and the power consumption of the connected devices. So, its main purpose is to buy us time to save files and shut down devices properly, rather than providing long-term power supply.

Now you understand how a UPS uninterruptible power supply protects our devices! The next time there's a power outage, remember to thank this silent “power bodyguard” that watches over us!