[aprssig] Emergency Power for Ham stuff (Universal motors too)

Robert Bruninga bruninga at usna.edu
Fri Jan 22 19:31:29 EST 2016

> Are you seriously suggesting that hams tap into
> what is a potentially lethal power supply, without
> warning about the dangers such a scheme presents,

Oops, sorry...,...

WARNING... if one doesn't understand HV electricty do not do this at

But, out rounding up firewood this afternoon for a record blizzard tonight,
I just realized that in addition to the 250-to-300 volt DC tap point one
one's solar array for anything modern with universal switching supplies,
one should also make a tap point at about 120 volts DC.

I realized my many kW of solar DC can run all kinds of other big things
that have"universal motors"!  Such as my electric chain saw to cut up the
wood I was gathering, and all these other things (with universal motors):

WARNING: you must NOT use their on/off switch on DC unless you add a
snubber capacitor across the points.  Better to run them on and off by
plugging and unplugging.  Making their use VERY dangerous of course!

These (with universal motors) will all run on DC (their switches WONT):

* Almost every tool in my shop (less the table saw)
* My lawnmower, weed whacker, leaf blower, mulcher
* my chain saw, snow blower, shop vac, vacuum cleaners
* Even my old converted player pianno (runs on a vacuum cleaner motor)
* My water heater (after adding a snubber across the thermostat)
* My electric bike, scooter, hoverboard (grin... NOT)
* Oh, and of course my electric car projects...

Come to think about it The only big AC motors I have that won't are the
heatpump, well pump, and refrigerator.

And in typing up this email, I just made a resolution to never buy an AC
motor again.  They are coming out with varriable speed and inverter driven
compressors and so surely DC capable refrigerators, heatpumps and well
pumps are here already if not just around the corner.


Wow, neat concept.  Do not invest in anything long term that wont run also
on DC for the long term.  If we made this a national policy and made
electric standards keep up with the safety issues (a simple resistor and
cap across all switches to make them DC safe, and we could really be ready
for the coming decades.  They can be made safe!  We just need the will to
do it...

One last point:

When I was a kid, my cubscout manual had the design for a 2 tube radio
complete with 150 volt battery.  This was for 8 year olds to put together
on mom's breadboard to meet a scout requirement.

I had written some of these DC ideas in my October (2012?) article in QST,
but they required me to remove them because Hams using HV DC is "unsafe".
Maybe they should review the Handbook and QST's I grew up with.

How many hams were killed by HV?  comapred to how many we kill every day
when they risk getting out of bed in the morning.  It can be proved that
getting up out of bed and carrying on a life is UNSAFE.

Better to learn...

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