I purchased a cheap car charger for a Nokia phone. After a while it started regularly blowing the fuse. After going through a package of six fuses from RadioShack, I bought a better charger.
You're probably lucky the charger blew out the fuses and not your phone. After looking inside a cheap charger, I think their motto is "do the cheapest thing that could possibly work".
Hey Ken. Thank you very much for writing such awesome posts. I have very little knowledge about EE, so your posts on power supplies (including this one) were very instructive and fascinating. I really like how you referenced everything.
Thanks. I learned a lot about power supplies writing these articles. By the way, I liked the title you submitted better, so I changed the article to match :-)