Anonymous White USB Charger: Teardown

Prompted by ericscott’s comment, I had to tear down the Anonymous White USB Charger to see what caused the bizarre current waveform when connected to the Arduino in a Glass Tile:

Tiles 2x2 - anon white charger - pulse detail - 50 mA-div
Tiles 2×2 – anon white charger – pulse detail – 50 mA-div

Start by grabbing opposite corners in a small vise and gently cracking the solvent-bonded joint between the sections:

Anon white charger - case cracking
Anon white charger – case cracking

Pull the base past the molded latches:

Anon white charger - case opened
Anon white charger – case opened

Behold: components!

Anon white charger - PCB top
Anon white charger – PCB top

On both sides of both PCBs!

Anon white charger - PCB bottom
Anon white charger – PCB bottom

The top half of both boards, above the isolation cut, handles the line voltage and the lower half handles the 5 V USB output. You’ll note the absence of extra-cost parts like voltage feedback or ahem safety fuses.

The IC on the right half is labeled DP3773, which doesn’t seem to exist, but is surely similar to the LP3773 Low-Power Off-Line / PSR Controller.

Treating the whole regulator as a black box simplifies the schematic:

Anonymous white charger - schematic
Anonymous white charger – schematic

The cap bridging the two sides should be a Y capacitor, but it’s an ordinary 1 nF ceramic cap with a generous 1 kV rating. As far as I can tell, having it inject AC line noise directly into the +5 V side of the USB supply is just a bonus.

The base markings again:

Anonymous white charger - dataplate
Anonymous white charger – dataplate

Whaddaya want for a buck, right?

Other folks give better teardown pr0n

3 thoughts on “Anonymous White USB Charger: Teardown

  1. Yup, there is a Chinese quality fully rated safety fuse. It’s the PCB track at top left. Of course, the ‘smell alert’ users get from the coincident burnt PCB is an added bonus feature.

    What I’d like to know is if the transformer includes quality primary to secondary isolation i.e. tape between the turns. That costs an extra 0.2 cents in the factory, so it’s only the best chargers that get that, ah, feature.

Spam comments get trashed, so don't bother. Comment moderation may cause a delay.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s