Sometimes, a 3-0 service has a monthly minimum charge that will blow
the hat clean off of one's head.
On Oct 4, 2006, at 5:26 AM,
ad4hk2004 wrote:
> Being that my Bridgeport mill is 1.5 HP, I use a
rotary convertor to
> change the 220X1 to 220X3... Not perfect but it
works...
> I did consider asking Consumers Power Co. to give me a price
for 3
> phase to the shop... But getting underground power to my
house
> required my atty petitioning the court for a 'show cause' order
-
> insiders at the company tell me their field supervisor is
still
> smarting from the corporate VP giving him a public chewing out
over
> that one - I suspect the bill would spin my
hat...
>
>
>
> denny
>
> --- In ham_amplifiers@yahoogroups.com,
"craxd" wrote:
>>
>> A 3 phase service is
mighty fine to have if one can afford to have it
>> put in. I've not
checked on the price in a while, but back in 1985, a
>> 200 amp 220
volt service ran around $2000 from the power company for
>> the
transformers, and the service entrance, meter base, etc was
>>
extra.
>> I was having one put in at my machine shop building I had
at the
>> time.
>> I wish I had the health back to do all
that again. At the time I had
>> an electric shop running, and a
machine and assembly shop a couple of
>> miles up the road. I used to
design and build custom fab machinery
>> for
>> the
railroads. Sure is a good business to be in. Anyhow, 3 phase can
>>
sure make life a lot easier if you plan on running reverseable
>>
motors,
>> and anything else that needs some umph behind it. One
could do it
>> with
>> a pony motor, but I'm not sure how
good that would work.
>>
>> Back in the old days, and some
do this now, is run a generator
>> (really
>> an alternator
without the rectifier stack) in a mobile supplying LV 3
>> phase to
run a HV transformer. That get's you out of running an
>> inverter. A
certain company down in Memphis, Tn used to supply a
>> mobile kW
(1800 PEP out) with the generator that way. I here about a
>> guy in
Florida building these today, and was buying the transformers
>> from
Galaxy Transformer. I recon he's built a few with tubes with
>>
handles. Of course you need enough engine to run it
too.
>>
>> Best,
>>
>>
Will
>>
>>
>> --- In ham_amplifiers@yahoogroups.com,
"Peter Voelpel" >>
wrote:
>>>
>>> To achieve 1,5% ripple from a 6-pulse
power supply of 5KV at 3A you
>> will
>>> need a
capacitor of 0,32???F.
>>> Without any cap ripple will be
4%.
>>> You will not here any hum from a transmitter without
capacitor in
>> the
>>> 6-pulse capacitor when using
sideband transmissions.
>>> From a carrier you here little hum on
zerobeat.
>>>
>>> The formula to find C for the
3-phase bridge circuit is the same as
>> for any
>>>
other circuit, just calculate C from XC by using 300Hz in the
>>
formula.
>>> How the transformer is connected does not matter,
usually the
>> primary will
>>> be delta for best
efficiency and the secondary will be star
>>
connected.
>>> You will have 2 diodes per leg. The voltage across
one winding is
>> dc/sqrt6.
>>>
>>> I my 7KV
4A CCS P/S I use UGE1112AY4 diodes by IXCYS, 3 per leg,
>> just
scewed
>>> one into the next.
>>>
>>>
>>>
>>>
The transformer secondary is 5KV +/-5%, +/-10% phase to phase, or
>>
2887V
>>> across one winding.
>>> I use 2???F 10KV for
smoothing and a crowbar overload circuit
>>> with
it.
>>>
>>> 73
>>>
Peter
>>>
>>>
>>>
________________________________
>>>
>>>
From: ham_amplifiers@yahoogroups.com
[mailto:
>> ham_amplifiers@yahoogroups.com]
>>>
On Behalf Of pentalab
>>>
>>>> Then, if we talk
3-phase supply and 6-puls rectifying,
>>>> lets say around 5 kV
DC potential, how much glitch C
>>>> is needed to achieve 1.5
percent ripple?
>>>
>>> ### Dunno. You would only have
5% ripple with NO cap.... and
>>> with a resonant choke set
up.....you probably wouldn't need any
>>> C at all ! [3
phase]
>>>
>>> ### IF no resonant choke setup... and
just a straight C input
>>> filter.... I'm guessing around 5-16 uf
would be plenty. It
>>> would also highly depend on the
load.
>>>
>>> ### I haven't found any formulae for a C
input filter HV
>>> supply........ with 3 phase. I don't have
access to 3 phase....
>>> so never pursued it. It would be the
ultimate setup. IF you
>>> find anything... let me know... as I'm
most interested. Somebody
>>> is going to ask me to engineer one
for em... so I had better
>>> research
it.
>>>
>>> ### I did see some info on C input 3 phase
HV supplies some
>>> where.... it's in Orr's older books.... but
not alot of info.
>>> Seems to me he had the 3 x primary's
connected in a "Delta".....
>>> and the 3 x secondary's tied in
a.. "star". The rectifier set
>>> up... if I remember, sorta
looked like just 2 x diodes per sec
>>> winding... one flipped
around If I remember. The RMS voltage
>>> per sec winding vs no
load HVDC output is what threw me.
>>> With say a 1 kv sec.... I'm
positive... the OCV hv wasn't 1414
>>> Vdc. [I may well be wrong
with this.. just going by
memory]
>>>
>>
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