[Elecraft] OT: RFI from Front Loading Washing Machines

[David Gilbert]

I worked in the discrete semi industry (engineer and then business 
manager) for thirty years, dealing with most of the major appliance 
companies in Asia, Europe, and the U.S.  By their own statements, the 
mechanical timer was far and away the most failure prone component in 
any washing machine.  The appliance industry in general resisted solid 
state controls for a long time due to inertia and tooling investments, 
but the first area where they came to us actively seeking help was to 
replace that damn mechanical timer.  They were just fed up with the 
customer complaints and the high costs of in-warranty service calls.

Aside from people like hams who have all sorts of tall metal outside 
connected one way or another to their electrical ground system, what 
percentage of people do you think have their washing machines zapped by 
nearby lightning strikes?  I can pretty much guarantee that it is a 
much, much smaller number than the percentage of mechanical timers that 
failed in the old washing machines.

Dave   AB7E



Joe Subich, W4TV wrote:
>> and might result in higher reliability of that portion of the product?
>>     
>
> Not hardly ... last time I visited my mother, I repaired 
> a pump seal in her 40 year old Westinghouse front loading 
> washer.  The mechanical timer is still running perfectly 
> after all these years ... and doing as many as 8 - 10 
> loads a week while we were growing up.  
>
> Those mechanical timer designs came from the commercial 
> (coin operated) world where they did hundreds of loads 
> (cycles) a week with nary a failure ... I maintained many 
> of those machines while working for my dad in high school
> and college. 
>
> The only advantage of the microprocessors are quick time 
> to market and the ability to implement water/energy saving 
> cycles demanded by the enviro-nuts at the cost of EMI 
> pollution. 
>
> The microprocessor controls certainly do not survive in 
> a surge/spike/lightning rich environment nearly as well 
> as the properly designed/sized mechanical timers. 
>
> 73, 
>
>    ... Joe, W4TV 
>   
>
>
>