At 05:54 PM 8/11/97 +0930, MikeS wrote: >But do you turn off the following when leaving your house - VCR, clock >radio, TV, microwave, hifi, fridge, freezer(ouch)? These all operate whilst >in 'non-attended' mode. Some would be a PITA to turn off every time you >left for a short duration - some not really possible (deep freeze) They all >pose a risk though. Yes. I turn off everything that has a switchmode supply in it which is not a brand name product by the biggest companies. So therefore, I use smoke detectors with interlock to the mains power so it turns off the power points within 10 seconds of being tripped (AND still leaves the light circuit active so I can see at night in case of alarm). I leave the clock radio on since it has one of those very nice conventional transformers AND a PTC in series with it. And if I go away for more than 2 days - I turn off the freezer - since I wouldn't risk the bacterial contamination in case the utility turned off the supply while I was gone and just happened to turn it back on a couple of hours before I got back, I know of one person who got sick for this very reason ! Risk assesment is an area which I have some philosophical interest both in terms of hardware design and software methodology. I am of the opinion that the 1 in 10 million is a bit optimistic when it comes to PC switchmode power supplies - UNLESS they are from the top brand name suppliers like HP, COMPAQ etc - then you *might* be close. In Australia we get lots of PC power supplies made by Chinese sweat shops and I've seen how they treat integrated circuits and switchmode transistors in respect of static - I am NOT impressed by what I have seen at ALL ! So when I have the opportunity to reduce risk - I do. I am not the sort of person who adds to risk or waves it away by saying "well the chances of being knocked over by a car are .... so why should I turn of my power supply cause I 'think' its a 1 in 10 million shot..." etc - This is very bad logic not congruent with engineering intellectualism leading to well designed and safety concious products. Faith and electronics reliability (to me) are mutually exclusive concepts. A faithful switchmode power supply is 'almost' an oxymoron ! rdgs mike PS: Insurance is NEVER a substitute for prevention, tell that to your children if/when they lose their favourite toys or photographs etc. Some say there is no magic but, all things begin with thought then it becomes academic, then some poor slob works out a practical way to implement all that theory, this is called Engineering - for most people another form of magic. Massen