USB flash drive voltage question?

Question

In my research, I discovered that a USB flash drive requires a +5V VCC in in the first pin. I want to manually power the USB, and am using a spare transformer to do so by slicing the wires on the transformer and attaching them to the USB. I understand this is difficult, do not comment on that section.

There is one snag I have run in to: I don't have a 5V OUT transformer.
I have 2 transformers:

1. A wall plug 120V IN, 5.2V 400mA out
2. A wall plug 120V IN, 4.8V 350mA out

Which, if either, will work without damaging the flash drive?

Answer 1

You need 5 volts — DC — for USB, not AC



Transformers provide only AC.

You need a small power supply, not a transformer.

However, many people erroneously get the terms confused.



So if those two units you have SPECIFICALLY say DC, then either would be ok. The tolerance on the 5 volts is ± 0.25 volts for proper operation.



I'd also check the supplies for voltage with no load with a multimeter. Some cheap ones have a much higher voltage with no load, which will damage things.



.

Answer 2

Most cheap make wall plug type 5v DC adaptor was not regulated. Its output is high as 8 volts with no load and has very high ripple (not a pure DC source). USB requires very stable and clean 5 volts DC source. DC power source taken from computer power supply is close to 99% pure DC.

USB uses wall plug type unclean DC might result have data lost even damage the flash memory.

Answer 3

sure, a flash stress could be wiped out, only like all different storage media. although, you shouldn't complication. on a similar time as i prefer to advise preserving a DVD and complicated-stress backup, your flash stress will possibly final 10 years of known use. A examine/write cycle refers to truthfully analyzing or changing the records on a flash stress. a famous flash stress must be waiting to stand up to a minimum of a million,000,000 examine/writes. additionally, look on the hot SSD (solid-state-disk) drives being bought in laptops. they are only super flash drives, and are meant for use like known disks. which ability they gained't fail any time quickly.

Answer 4

i would personally use your 4.8v transformer. you need to make sure the output is DC not AC... Have fun :P