OT: RE: [aprssig] Field Day power (220 VDC)

Dave Baxter dave at emv.co.uk
Tue Oct 23 04:35:03 EDT 2007


And when the "Social and entertainment" tent runs out of "Joy" needing
more to be brought in, hope you have another conventional vehicle to do
that with, or the RF opp's wont like you..  ;-)

Take great care with distributing HV(ish) DC out and about.  It's bad
enough getting a "belt" from 240VAC, but you do tend to jerk away from
it.  HVDC is somewhat different.

Knowing what some US power connectors are like in their "stay in the
socket abilitiy" stakes, I wouldn't like to do that in anything other
than a perfectly dry environment, and then only with twist-n-lock type
connectors.

Now, if you can convince the Prius to power up it's 3-phase converter,
you could run some "Serious" RF power.  Much more fun!...

Dunno why, but there is still something deeply satisfying about large
multi cylinder diesel gen-sets.  You can run them of vegi oil of course
too..   Then you have enough power for all the domestic needs.  Fridge,
kettle, microwave, TV, Video, fan heaters etc.   I kid you not!  If you
are going to do a full weekend field day, you might as well be
comfortable.

Strange how you can sleep right next to one such beast, but if it so
much as misses a beat, you're wide awake in an instant...

Guess you could run the Prius's engine on Methanol, if the RF opp's
don't find it first!...

Fond memories of field day hazes in the past...

73.

Dave G0WBX.
   

> -----Original Message-----
> From: Robert Bruninga
> Sent: Sunday, October 21, 2007 12:06 AM
> To: 'TAPR APRS Mailing List'
> Subject: [aprssig] Field Day power (220 VDC)
> 
> At today's all day ham radio Field event I tried out my new 
> field-day power distribution system using the 220 VDC from a Prius.
> 
> Using the car's 220 VDC battery, (and 50 kW internal gas 
> engine generator if needed), I was able to power just about 
> everything.
> Turns out that all  laptop power supplies (rated at 115-230 
> VAC) will run directly on 220 VDC and all other equipment at 
> each of the Ham radio stations used their typical 20 amp 12 
> VDC SWITCHING power suppplies all fed from the 220 VDC source.
> 
> See: 
> http://web.usna.navy.mil/~bruninga/FD-Prius-Power.html
> 
> Tunrs out almost all modern (dual voltage) SWITCHING supplies 
> (when switched to the 220 Volt position) will run just fine 
> on 220 VDC.  And laptop power supplies (rated at 115 to 230 
> VAC) will usually run just fine without even flipping a 
> voltage switch (they don't have one).
> 
> Anyway, using lightweight #18 extension cords can deliver 
> killowatts of power over hundreds of feet using this method.
> So... Just experimenteing, but it appears to work just fine.
> Delivering a kW is only drawing 5 amps on the lightweight 
> extension cords at 220 VDC.
> 
> Bob, WB4APR
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