[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: I X-Rayed my Apple IIe



Grant Stockly wrote:
Those power levels sound much more doable, but 480 Watts is still
quite a supply!  What type of power supply does it use?


Some units use a transformer to go from 80v to 800v and then use diode
doublers to get it to 80kv.

After 100 stages of multiplication, getting 6-10mA would require some
pretty good sized capacitors at 60Hz, so I'm guessing that this is a
high-frequency switching supply.

Along with each doubler step there is often a feedback resistor.  On a
450kv system you will have a voltage dividor with a resistance of
around 1.5G.  : )


When I was in high school, I imagined operating them with an induction
coil, but the highest voltage DC supply I ever made was about 2800v
(at 15mA), and it was a linear supply.  A flyback supply for 30kV at
about 1mA seemed practical, but I never aspired to higher powered vacuum
tube circuits.  ;-)


Even a low power x-ray tube can be very dangerous.  If you do anything
like this you should take a radiation safety course, get a book, survey
meter (and calibrate it).

X-rays are invisible death rays if you don't take proper safety
measures.

I understand--physics was my subject even then.  (I have also always
been a lead collector--I'm guessing I have a couple hundred pounds,
most of it from thrown wheel weights I found while riding my
bicycle.  ;-)

I still remember standing on the foot X-ray in the Thom McCann
shoe store, holding the button down and wiggling my toes while
peering at the fluoroscope.  ;-)

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."