Cheap chinese 220v->5v transformator board safe?

[prebs]

i found this in my parts bin, and I think it's from some cheap chinese electronics from ebay. I would like to re-purpose this for another project, but I don't know much about power supplies.
Given that this is from china I'm worried that i might not be too safe, especially given the few components.

It's rated for 300-500mA out, 120-220 AC in. I only need 100mA at 5v DC so that should be okey.

https://www.dropbox.com/s/jkijcwfgabvbi5p/bilde%201.JPG

https://www.dropbox.com/s/4ppyqstdq68el6m/bilde%202.JPG


Would you trust it ?

[SeanB]

Safer than a lot I have seen. Decent isolation slots between the mains and LV side, but no RF suppression capacitor ( though the board is marked for one but it is not installed, top of the first pic), and the input actually uses a fusible resistor and a real bridge rectifier.

Might not pass insulation test on the transformer, but likely will work well enough as a simple poorly regulated supply, as there is no secondary side feedback so the output voltage is going to vary with load somewhat, depending on the primary side regulation to keep it reasonably constant. You might find that at no load it might deliver closer to 6V than 5V, though likely at 500mA it likely will only deliver 4V5.

[prebs]

Cool, thanks for the feedback. That made me feel much safer