5V power supplies (or 5VDC power supplies) are one of the most commonly used power supplies today. Generally, a 5 VDC output is obtained from a 50 VAC or 240 VAC input using a combination of transformers, diodes and transistors.
(5 volts) A standard voltage required by chips and drives in a computer. The power supply converts 120 volts alternating current (AC) to 5 volts direct current (DC) as well as 3.3V and 12V.
So now you know that you can get 12Vdc from 5Vdc, but as you increase the voltage the output current must be reduced to respect the conservation principle. So in reality you can only draw a very limited amount of power from your converter.
A 1A device means that for a power supply of a certain voltage (5V for USB) the device “asks” 1A from the power supply. With a 1A charger, this means the electronic devices in the charger can handle 1A before they break.
What is a DC-DC charger? Put simply, they are a smart charger that runs on 12 volts. They do this by taking the output of your vehicle’s alternator and producing an output voltage and current ideal for charging and/or servicing your auxiliary battery.
There are three subgroups of regulated power supplies: linear, switched, and battery based. Of the three basic regulated power supply designs, the linear system is the least complicated, but switched and battery powered power supplies have their merits.
A 5V output is most commonly used when the end application needs to be powered from a USB port, e.g. a mini/micro B or type C connector. Or, if space is at a premium, the DC cable and USB plug can be removed entirely and replaced with a socket on the case, like phone chargers.
Most computer USB ports deliver 5V power with a maximum current of 0.5A. This amount of current is standard for most computers and means that the total output is 2.5 watts at best amounts to. Later USB designs bring this current to 0.9A.
Once the initial specifications of a DC/DC design are selected (e.g. input voltage range, output voltage, output current), the first step is to select a converter IC. The desired DC-DC topology will limit this choice. If the input voltage is greater than the output voltage, choose a buck topology (i.e., step-down).
But the USB standard offers another advantage that explains why USB has found its way into our cars: standardized voltage outputs. Because USB connections output 5V DC, devices using this type of adapter are all designed to operate at this input voltage.
No, you cannot safely power an LED with 5V without a resistor. The resistor is absolutely 100% needed. The resistor is not placed there on a whim, it is needed to set the current based on the supply voltage minus the LED forward voltage and the resistance value of the resistor.
The device will most likely burn out. Depending on the type of device and the capacity of the 12V supply, connecting a 12V supply to a device with a maximum voltage rating of 5V may cause hazards – fire, explosion, etc.
Most phones and other devices can handle 5V/2.4A. When fast charging you are looking for something that will increase the voltage by 5V, 9V, 12V and more or increase the current to 3A and more.
All chargers take your mains voltage – typically 120 or 220 volts – and convert it to 5 volts. It is this 5 volt side that is then connected to your device to charge it. Not only is 5 volts the same for all chargers, it’s part of the USB standard. Power provided via USB cable is 5 volts, period.
The different types of chargers
Laptop chargers: Unfortunately there are still no standard chargers for laptops. You should get a charger that is specifically designed for your laptop. Connectors are not standardized, so you probably won’t accidentally connect the wrong charger to your laptop.