Cheap Asian Mains Adapters - a Nuisance for Mankind

Salve All,

one might think that in the 21. Century it's no rocket science to develop and produce high quality mains adapters. And of course it isn't. I've been a PCB designer in the 80's working for a company providing PCB solutions to the industry and military and even back then, in the dark ages of electronics, it wasn't a challenge to design and manufacture high quality mains adapters. It was a question of pricing!

The real mass-distribution of wall warts started in the early 90's as design policies and laws made it necessary for PCB designer to "outsource" the high voltage components into an extra housing and keep it separated from the low voltage circuitry of the appliance. This was the birthday of the massproduced cheap wall wart usually from chinese production.

Unfortunately mass-produced cheap mains adapters have a number of drawbacks as my experience of life of the last 35 years shows.

• They are usually poorly designed (PCB, component placement, etc.).


• They are built with low quality components (FR2 Phenol Hard Paper instead of FR4 for the PCB).


• They are built with components whose specifications are bordering to the appliance operation (capacitors with a 200V voltage instead of 400V).


• They have bad temperature design through bad component placement and bordering component specifications (component overload) which leads to to massive temperature problems.


• Simple circuit design leads to interferences and voltage fluctuation or instability.


• Electricity consumption turned into heat during no-load operation.


• They have a relative short life span owed due to all of the above mentioned problems.


• They tend to damage/destroy other appliances in case of failure.

Below you find a series of images which show an "exploded" wall wart which is of course the usual capacitor failure. When the mains adapter ceased to function it was in use in a server room to provide power to a small switch. The mains adapter failure destoyed the electronics of an external harddisk, rendering the electronics in the HD-housing and the harddisk itself unusable, and a whole server which was connected to the same wall outlet. The harm was done despite the fact that all appliances destroyed by the wall wart had their own surge prevention circuitry in place. Interestingly the switch wasn't destroyed.

The main damage wasn't the unusable hardware, it were the man hours to set up a new server and to retrieve the data from the server/external harddrive.

As a result I recommended my customer to replace all mains adapter through high quality systems from a german company specialized in industrial grade power supplies. Interestingly this lead also to a lower consumption of electricity.













In a professional environment it is wise to choose quality and durability over price because the cheapest solution becomes the most expensive in the end!

Best regards

Howard

Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for.
Socrates