[Info-vax] OT: the Daily WTF for today is a VAX/VMS story

[William Pechter]

In article <n9qlta$2rv$1 at Iltempo.Update.UU.SE>,
Johnny Billquist  <bqt at softjar.se> wrote:
>On 2016-02-14 19:53, Steven Schweda wrote:
>>> [...] Anyone with half a brain [...] There is no spinup
>>> time. You go from standstill to full speed immediately,
>>> always. [...]
>>
>>     Perhaps the other half-brain is the one which paid some
>> attention in its physics class.  Instantaneous anything can
>> be tough to obtain with finite resources.  Or is your claim
>> that the rotor here has no mass (moment of inertia, actually,
>> so perhaps it's the radius which is zero, not the mass).
>
>Which is why when I played with 3-phase AC motors, they were firmly 
>attached to a bench, and the bench had a tendency to jump when power was 
>applied. And we're talking about a big bench...
>
>But yes, "instantaneous" is a strong word here. The inertia makes it 
>impossible to really be instantaneous. But the acceleration is violent, 
>and the physical forces are large.
>
>An RP06 takes about 30-45 seconds to spin up... It is no where near the 
>way you can get an AC motor to work.
>
>	Johnny
>
>-- 
>Johnny Billquist                  || "I'm on a bus
>                                   ||  on a psychedelic trip
>email: bqt at softjar.se             ||  Reading murder books
>pdp is alive!                     ||  tryin' to stay hip" - B. Idol


In 3/8/09 in an article you posted in google groups -- wouldn't two phase mean
an AC motor...

just a poor old ex-DEC Field Engineer here... there's no way the RP06
used a DC motor...

Bill


Pat Farrell wrote:
> Peter Flass wrote:
>> an old 9-track tape drive I'm going to try out sometime, but I'd be
>> afraid of a disk drive.
> 
> And for an RP06, you need three phase power.
> 
> IIRC, it required three phase but only used one phase.
If it only used one, it wouldn't need 3-phase now, would it? :-)
Actually, it uses 2 phases (motor).

        Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: b... at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol
-- 
-- 
Digital had it then.  Don't you wish you could buy it now!
pechter-at-gmail.com  http://xkcd.com/705/