How to make a desktop charger from a 5V power supply?

Question

Iron

There is an AC power supply 5V 5A

I would like to assemble a charger for 4 usb ports, what scheme should I use between the power source and the usb connector itself. On the Internet, many sources indicate that Apple devices will not charge without a divider on resistors to data + and data-, while for htc, samsung other ratings and schemes are indicated, and from a computer port, for example, all devices are charged. In addition, I would like to know if voltage protection is needed, on one resource they advised a tvs diode with a fuse. In general, I would like to hear the opinion of experts.

Answer 1

The USB standard contains the power setting of the connected device. The device tells the PC how much current it needs, the PC responds with how much it can afford. All this happens at a current consumption of up to 100mA, after which the current rises to the agreed level. In the case of "dumb" charging, there will be no communication via USB. Most modern phones will charge at 0.5-1A if the data pins are simply shorted. Some will consume more if you install resistors of the desired value (see Charger Doctor on aliexpress - garbage that sorts through all known ratings, achieving the highest current consumption. Not to be confused with shitty voltmeters of the same name).
In general, an Apple with a stupidly shorted bus won't charge at all. Resistors are required.

Answer 2

I can recommend a good video. there the main part about the power supply is adjustable, but there is a usb charger in it https://www.youtube.com/watch?v=Wz6b9o9TE3I