Rich,
I forget what they call that now, but they sure are! There's a minimum
you pay whether you use it or not.
Best,
Will
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
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@..., "craxd" <craxd1@> 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@..., "Peter Voelpel" <df3kv@>
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@... [mailto:
ham_amplifiers@...]
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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