Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Stefan Skoglund via cctalk]

tor 2018-07-26 klockan 12:15 -0700 skrev Chuck Guzis via cctalk:
> On 07/26/2018 11:51 AM, Ed Sharpe wrote:
> > 
> > smecc has  stashed a  huge  mother gen  set115  60cy  in  115
> > 400 cy  out. was used to  runrca avq  10  raradr
> > we  have
> > but  could  run many   many things... it is  huge,,, these things
> > exist out there  if you need one,...
> 
> 400Hz power was also used in aviation gear.  I remember having a
> stock
> of small surplus 400Hz transformers salvaged from various bits of
> equipment purchased on Chicago's "Surplus Row".
> 
> Transformers are much smaller than their 50/60 Hz cousins.
> 
> On the other hand, when I worked in a steel mill, much of the power
> distribution was 25Hz.  Transformers were much larger.  At some
> point,
> one of the mills converted their lighting from incandescent to
> mercury-vapor running from that 25Hz supply.  I'm surprised that
> nobody
> experienced seizures from the flicker.
> 

The electric arc furnace works much better at 25 Hz.

The hydro power station in Trollhättan was first built as a 25 Hz
because :
desiredness of electric power for the metallurgical industry in
Trollhätan.
Trouble: the other intended customer Gothenburg city wanted 50 Hz.

The last 25 Hz generator in Trollhättan was taken off the electric grid
in 1959.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Fritz Mueller via cctalk]

> On Jul 26, 2018, at 12:19 AM, Mattis Lind via cctalk  
> wrote:
> 
> You need to move the motor to a new position in the RK05. The drive is
> already prepared for all this. It is just the pulley, moving the motor and
> the 220VAC jumper that is needed.

I'm just working on my second RK05 drive now, to see if I can get it going by 
VCF West (I'm going to get crazy this year and rent a truck and show the 11/45, 
so some other people can enjoy it :-))

In any case, I can confirm that the power supply and transformers are 
jumper-able for 220VAC, and the motor is on a spring-tensioned swing arm, so it 
probably accommodates a different pulley just fine.  HOWEVER, I noticed today 
that my particular motor has an ominous bright orange sticker on it that 
explicitly says "60 Hz ONLY".  As far as I know, its an original motor.  FWIW!

https://drive.google.com/file/d/1ZpupgCaQ2InqQrv1uruBJPZZGlDUTuwW/view 


cheers,
   --FritzM.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Fritz Mueller via cctalk]

> On Jul 26, 2018, at 12:19 AM, Mattis Lind via cctalk  > wrote:
> 
> You need to move the motor to a new position in the RK05. The drive is
> already prepared for all this. It is just the pulley, moving the motor and
> the 220VAC jumper that is needed.

I'm just working on my second RK05 drive now, to see if I can get it going by 
VCF West (I'm going to get crazy this year and rent a truck and show the 11/45, 
so some other people can enjoy it :-))

In any case, I can confirm that the power supply and transformers are 
jumper-able for 220VAC, and the motor is on a spring-tensioned swing arm, so it 
probably accommodates a different pulley just fine.  HOWEVER, I noticed today 
that my particular motor has an ominous bright orange sticker on it that 
explicitly says "60 Hz ONLY".  As far as I know, its an original motor.  FWIW!

https://drive.google.com/file/d/1ZpupgCaQ2InqQrv1uruBJPZZGlDUTuwW/view 


cheers,
   --FritzM.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Alan Frisbie via cctalk]

Chuck Guzis  wrote:

> In WWII radio equipment, MGs in a unitzed form called
> "dynamotors" were used to supply the high-voltage anode voltage
> for the tubes.

And long after WWII!   In the 1960s, I had a Motorola 140D (140
for the power, "D" standing for Dynamoter) mobile radio (6 meter
ham band) in my car.   Everytime I keyed the mike, the dynamoter
would instantly spin up with a loud whine.   Such radios were
normally housed in the trunk of the car and required heavy wire
to carry the 12 volt battery current for the dynamoter.

My Monarch 10EE lathe originally came with a big motor-generator
to power the variable-speed DC motor.   Later versions use
thyratrons, while even later ones were solid state, but they all
continued to use DC motors.   The variable-speed DC drive was
very similar (identical?) to elevator drives, known as the
Ward-Leonard system.

To bring this back to the RK05, someone asked if anyone had a
copy of the RK05 IPB.   If you still need it, let me know and
I'll dig it out.   I haven't packed it for my move yet, but
the drives are.

Alan

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Chuck Guzis via cctalk]

On 07/26/2018 11:51 AM, Ed Sharpe wrote:
> 
> smecc has  stashed a  huge  mother gen  set115  60cy  in  115
> 400 cy  out. was used to  runrca avq  10  raradr we  have
> but  could  run many   many things... it is  huge,,, these things
> exist out there  if you need one,...

400Hz power was also used in aviation gear.  I remember having a stock
of small surplus 400Hz transformers salvaged from various bits of
equipment purchased on Chicago's "Surplus Row".

Transformers are much smaller than their 50/60 Hz cousins.

On the other hand, when I worked in a steel mill, much of the power
distribution was 25Hz.  Transformers were much larger.  At some point,
one of the mills converted their lighting from incandescent to
mercury-vapor running from that 25Hz supply.  I'm surprised that nobody
experienced seizures from the flicker.

--Chuck

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Ed Sharpe via cctalk]

smecc has  stashed a  huge  mother gen  set    115  60cy  in  115 400 cy  out.
was used to  run    rca avq  10  raradr we  have but  could  run many   
many things... it is  huge,,, these things exist out there  if  you need 
one,
 
Ed#  www.smecc.org 
In a message dated 7/26/2018 9:36:04 AM US Mountain Standard Time, 
cctalk@classiccmp.org writes:

 
On Thu, Jul 26, 2018 at 5:28 PM, Chuck Guzis via cctalk

 wrote:
> On 07/26/2018 08:26 AM, Tony Duell wrote:
>
>> I believe if you want to be pedantic that a motor-generator set is a motor
>> (with an armature/rotor and a field/stator) mechanically coupled to a
>> generator (with its own armature/rotor and field/stator) whereas a
>> dynamotor has a common field/stator (and possibly both armature
>> windings have to be wound on the same core).
>
> Hence my term "unitized", which I thought to give the basic idea without
> going into excessive detail on an obsolete device.

This is classiccmp. We 'do' obsolete devices here :-)

>
> In connection with similar low-power high-voltage supplies, I could also
> have mentioned vibrator-transformer supplies, run from DC battery, used
> very often in lower-power tube gear, such as auto radios and even photo
> strobe flash.

Indeed. I've never seen a photoflash using such a supply, but I have read
about them. One day I'll add one to my collection.

They were commonly used in car radios over here too.


>
> The high-voltage DC was obtained from the transformer secondary by
> either a traditional tube (very often cold cathode gas) rectifier, later

0Z4 IiIRC wa a common rectifier valve.

> solid-state (selenium or silicon) or an additional set of contacts on
> the vibrator itself. Notorious for kicking up all sorts of RF noise.

The latter was known as a 'synchronous vibrator' (at least over here)
as the 2 sets of contacts were synchronised to (a) apply a pulse to one
end of the primary winding and (b) select the appropriate end of
the secondary which will have an high voltage pulse of the correct
polarity.

A mad friend of mine commented that a google search for a spare
part for his car radio directed him to an awful lot of 'adult' sites...

-tony

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Ed Sharpe via cctalk]

Chuck...     horrible  flashback of  using this  strobe  unit in my  younger  
days as a photographer.  Still  was nicer than a  pocket  full of  flashbulbs  
being  set off in a  suit  pocket  from  carpet static   electricity...


We  actually  still have  of of these units in the  photographic  collection...
 
 
Ed#   www.smecc.org 
 
In a message dated 7/26/2018 10:34:57 AM US Mountain Standard Time, 
cctalk@classiccmp.org writes:

 
Either was vastly more compact than the Graflex

stroboflash-2x225V batteries in a very heavy supply.

--Chuck

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Chuck Guzis via cctalk]

On 07/26/2018 09:35 AM, Tony Duell wrote:
> On Thu, Jul 26, 2018 at 5:28 PM, Chuck Guzis via cctalk

> Indeed. I've never seen a photoflash using such a supply, but I have read
> about them. One day I'll add one to my collection.

I recall fooling with a 60s era Dormeyer model.  Not only did it use a
vibrator supply, but also a rechargeable stainless-steel enclosed
battery.  A very compact unit in comparison to those units using the
510V primary battery.  Either was vastly more compact than the Graflex
stroboflash-2x225V batteries in a very heavy supply.

--Chuck

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Tony Duell via cctalk]

On Thu, Jul 26, 2018 at 5:28 PM, Chuck Guzis via cctalk
 wrote:
> On 07/26/2018 08:26 AM, Tony Duell wrote:
>
>> I believe if you want to be pedantic that a motor-generator set is a motor
>> (with an armature/rotor and a field/stator) mechanically coupled to a
>> generator (with its own armature/rotor and field/stator) whereas a
>> dynamotor has a common field/stator (and possibly both armature
>> windings have to be wound on the same core).
>
> Hence my term "unitized", which I thought to give the basic idea without
> going into excessive detail on an obsolete device.

This is classiccmp. We 'do' obsolete devices here :-)

>
> In connection with similar low-power high-voltage supplies, I could also
> have mentioned vibrator-transformer supplies, run from DC battery, used
> very often in lower-power tube gear, such as auto radios and even photo
> strobe flash.

Indeed. I've never seen a photoflash using such a supply, but I have read
about them. One day I'll add one to my collection.

They were commonly used in car radios over here too.


>
> The high-voltage DC was obtained from the transformer secondary by
> either a traditional tube (very often cold cathode gas) rectifier, later

0Z4 IiIRC wa a common rectifier valve.

> solid-state (selenium or silicon) or an additional set of contacts on
> the vibrator itself.  Notorious for kicking up all sorts of RF noise.

The latter was known as a 'synchronous vibrator' (at least over here)
as the 2 sets of contacts were synchronised to (a) apply a pulse to one
end of the primary winding and (b) select the appropriate end of
the secondary which will have an high voltage pulse of the correct
polarity.

A mad friend of mine commented that a google search for a spare
part for his car radio directed him to an awful lot of 'adult' sites...

-tony

Re: 400Hz supplies; was: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Chuck Guzis via cctalk]

On 07/26/2018 08:26 AM, Tony Duell wrote:

> I believe if you want to be pedantic that a motor-generator set is a motor
> (with an armature/rotor and a field/stator) mechanically coupled to a
> generator (with its own armature/rotor and field/stator) whereas a
> dynamotor has a common field/stator (and possibly both armature
> windings have to be wound on the same core).

Hence my term "unitized", which I thought to give the basic idea without
going into excessive detail on an obsolete device.

In connection with similar low-power high-voltage supplies, I could also
have mentioned vibrator-transformer supplies, run from DC battery, used
very often in lower-power tube gear, such as auto radios and even photo
strobe flash.

The high-voltage DC was obtained from the transformer secondary by
either a traditional tube (very often cold cathode gas) rectifier, later
solid-state (selenium or silicon) or an additional set of contacts on
the vibrator itself.  Notorious for kicking up all sorts of RF noise.

But this is way off-topic.

--Chuck

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning via cctalk]

> On Jul 26, 2018, at 11:26 AM, Tony Duell via cctalk  
> wrote:
> 
> On Thu, Jul 26, 2018 at 4:14 PM, Chuck Guzis via cctalk
>  wrote:
> 
>> Such MG setups were very common in industry before modern
>> semiconductors.  When I had a summer job showing movies at a drive-in
>> theater (a long time ago), the supply for the carbon-arc lamps was a
>> 40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
>> radio equipment, MGs in a unitzed form called "dynamotors" were used to
>> supply the high-voltage anode voltage for the tubes.  Electroplating
>> shops similarly used large DC generator setups to supply plating current.
> 
> I believe if you want to be pedantic that a motor-generator set is a motor
> (with an armature/rotor and a field/stator) mechanically coupled to a
> generator (with its own armature/rotor and field/stator) whereas a
> dynamotor has a common field/stator (and possibly both armature
> windings have to be wound on the same core).

Yes, so Wikipedia is wrong to describe a dynamotor as a motor-generator and 
show it in the m-g article rather than the rotary transformer article.

I remember the dynamotors shown in that photo, my father had that exact unit 
and several other "Command Set" radios.  The dynamotors clearly had a single 
armature, with input brushes at one side and output brushes at the other.

paul

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning via cctalk]

> On Jul 26, 2018, at 10:54 AM, Anders Nelson  wrote:
> 
> To get that power, did they have to use a rotary convertor from 60Hz 3-phase 
> to get 400Hz?
> 
> https://en.wikipedia.org/wiki/Rotary_converter

No, a motor-generator: https://en.wikipedia.org/wiki/Motor–generator.  Same 
purpose, but constructed as a motor attached to a generator, rather than the 
two merged into a single armature.

http://www.bitsavers.org/pdf/cdc/cyber/cyber_70/fieldEngr/60142400B_6000_Series_Site_Prep_Sep65.pdf
 shows the ones CDC used, starting on page 27.

paul

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Jon Elson via cctalk]

On 07/26/2018 10:26 AM, Tony Duell via cctalk wrote:

On Thu, Jul 26, 2018 at 4:14 PM, Chuck Guzis via cctalk
 wrote:


Such MG setups were very common in industry before modern
semiconductors.  When I had a summer job showing movies at a drive-in
theater (a long time ago), the supply for the carbon-arc lamps was a
40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
radio equipment, MGs in a unitzed form called "dynamotors" were used to
supply the high-voltage anode voltage for the tubes.  Electroplating
shops similarly used large DC generator setups to supply plating current.

I believe if you want to be pedantic that a motor-generator set is a motor
(with an armature/rotor and a field/stator) mechanically coupled to a
generator (with its own armature/rotor and field/stator) whereas a
dynamotor has a common field/stator (and possibly both armature
windings have to be wound on the same core).

Yes, a dynamotor has ONE armature with a commutator on each 
end. There is one set of field poles for the whole unit, 
too.  The low-voltage input and high-voltage output windings 
are laid in the same slots in the armature.


Jon

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Jon Elson via cctalk]

On 07/26/2018 09:54 AM, Anders Nelson via cctalk wrote:

To get that power, did they have to use a rotary convertor from 60Hz
3-phase to get 400Hz?


IBM mainframes in the late 1950's early 1960's (707x and 
709x series) used motor generators to generate 400 Hz 
3-phase power, which was distributed to all the major 
components.


For the 360, they came up with a solid state version, it ran 
the CPU, memory and such on 2500 Hz single-phase power, 
using a "converter-inverter".  It rectified and filtered the 
3-phase 50- or 60-Hz input to DC, and then used ultra-fast 
SCRs to invert it.  But, the energy stored in the filter 
caps in that was way smaller than the rotational energy in a 
motor generator set.  So, the 360 was susceptible to power 
glitches and dips.  For the 370, they went back to a 
motor-generator set actually INSIDE the CPU cabinet to 
produce 415 Hz 3-phase power.  Larger systems often had a 
UPS with electronic inverters in them.


Jon

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Tony Duell via cctalk]

On Thu, Jul 26, 2018 at 4:14 PM, Chuck Guzis via cctalk
 wrote:

> Such MG setups were very common in industry before modern
> semiconductors.  When I had a summer job showing movies at a drive-in
> theater (a long time ago), the supply for the carbon-arc lamps was a
> 40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
> radio equipment, MGs in a unitzed form called "dynamotors" were used to
> supply the high-voltage anode voltage for the tubes.  Electroplating
> shops similarly used large DC generator setups to supply plating current.

I believe if you want to be pedantic that a motor-generator set is a motor
(with an armature/rotor and a field/stator) mechanically coupled to a
generator (with its own armature/rotor and field/stator) whereas a
dynamotor has a common field/stator (and possibly both armature
windings have to be wound on the same core).

-tony

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Anders Nelson via cctalk]

Best mailing list ever. Thanks for the detail!

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Thu, Jul 26, 2018 at 11:14 AM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 07/26/2018 07:54 AM, Anders Nelson via cctalk wrote:
> > To get that power, did they have to use a rotary convertor from 60Hz
> > 3-phase to get 400Hz?
> >
> > https://en.wikipedia.org/wiki/Rotary_converter
>
> As Paul mentioned, less a "rotary converter" than a AC motor-AC
> generator hookup.  One advantage is that the rotational inertia in such
> a setup does have the ability to smooth over small power disruptions.
>
> Such MG setups were very common in industry before modern
> semiconductors.  When I had a summer job showing movies at a drive-in
> theater (a long time ago), the supply for the carbon-arc lamps was a
> 40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
> radio equipment, MGs in a unitzed form called "dynamotors" were used to
> supply the high-voltage anode voltage for the tubes.  Electroplating
> shops similarly used large DC generator setups to supply plating current.
>
> 3 phase full-wave rectified AC has approximately 87% DC content at 6x
> the supply frequency.  So for 400Hz, the ripple is only 13 percent at
> 2400 Hz before filtering.
>
> --Chuck
>
>

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Chuck Guzis via cctalk]

On 07/26/2018 07:54 AM, Anders Nelson via cctalk wrote:
> To get that power, did they have to use a rotary convertor from 60Hz
> 3-phase to get 400Hz?
> 
> https://en.wikipedia.org/wiki/Rotary_converter

As Paul mentioned, less a "rotary converter" than a AC motor-AC
generator hookup.  One advantage is that the rotational inertia in such
a setup does have the ability to smooth over small power disruptions.

Such MG setups were very common in industry before modern
semiconductors.  When I had a summer job showing movies at a drive-in
theater (a long time ago), the supply for the carbon-arc lamps was a
40hp motor powered by 3-phase 60Hz, driving a DC generator.  In WWII
radio equipment, MGs in a unitzed form called "dynamotors" were used to
supply the high-voltage anode voltage for the tubes.  Electroplating
shops similarly used large DC generator setups to supply plating current.

3 phase full-wave rectified AC has approximately 87% DC content at 6x
the supply frequency.  So for 400Hz, the ripple is only 13 percent at
2400 Hz before filtering.

--Chuck

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Anders Nelson via cctalk]

To get that power, did they have to use a rotary convertor from 60Hz
3-phase to get 400Hz?

https://en.wikipedia.org/wiki/Rotary_converter

=]
--
Anders Nelson

+1 (517) 775-6129

www.erogear.com


On Thu, Jul 26, 2018 at 10:49 AM Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:

>
>
> > On Jul 26, 2018, at 9:55 AM, W2HX via cctalk 
> wrote:
> >
> > That is not the whole story of 400Hz. The other part of that story is
> that now, all of the downstream equipment that uses the 400 Hz can have
> much simpler AC to DC power supplies in them. At 400 Hz it is much easier
> to regulate and filter out ripple. So instead of every piece of equipment
> each having lots of large capacitors, now they only need small capacitors.
> Space is at a premium as well as weight on a plane.
>
> This even applies to some terrestrial equipment.  CDC used 400 Hz 3-phase
> power for the 6000 series mainframes.  3-phase power cuts the ripple by a
> large fraction and raises the ripple frequency 3x; 400 Hz instead of 60 or
> 50 raises the ripple frequency further by that ratio.  So high power
> supplies get much smaller, both in the transformers and in the filter
> capacitors.
>
> The 400 Hz came from motor-generators.  Those also clean up the power a
> lot, because any spikes or brief dips are absorbed by the mechanical
> intertia and don't appear on the output.
>
> paul
>
>
>

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning via cctalk]

> On Jul 26, 2018, at 9:55 AM, W2HX via cctalk  wrote:
> 
> That is not the whole story of 400Hz. The other part of that story is that 
> now, all of the downstream equipment that uses the 400 Hz can have much 
> simpler AC to DC power supplies in them. At 400 Hz it is much easier to 
> regulate and filter out ripple. So instead of every piece of equipment each 
> having lots of large capacitors, now they only need small capacitors. Space 
> is at a premium as well as weight on a plane. 

This even applies to some terrestrial equipment.  CDC used 400 Hz 3-phase power 
for the 6000 series mainframes.  3-phase power cuts the ripple by a large 
fraction and raises the ripple frequency 3x; 400 Hz instead of 60 or 50 raises 
the ripple frequency further by that ratio.  So high power supplies get much 
smaller, both in the transformers and in the filter capacitors.

The 400 Hz came from motor-generators.  Those also clean up the power a lot, 
because any spikes or brief dips are absorbed by the mechanical intertia and 
don't appear on the output.

paul

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[W2HX via cctalk]

That is not the whole story of 400Hz. The other part of that story is that now, 
all of the downstream equipment that uses the 400 Hz can have much simpler AC 
to DC power supplies in them. At 400 Hz it is much easier to regulate and 
filter out ripple. So instead of every piece of equipment each having lots of 
large capacitors, now they only need small capacitors. Space is at a premium as 
well as weight on a plane. 

From: cctalk  on behalf of Anders Nelson via 
cctalk 
Sent: Thursday, July 26, 2018 8:26 AM
To: Carlos E Murillo-Sanchez; General Discussion: On-Topic and Off-Topic Posts; 
carlos_muri...@ieee.org
Subject: Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

Omg finally I know why airplanes use 400Hz, thank you! Honestly that's been
on my mind for years.

=]

On Wed, Jul 25, 2018 at 2:06 PM Carlos E Murillo-Sanchez via cctalk <
cctalk@classiccmp.org> wrote:

> Eric Smith via cctalk wrote:
> > On Wed, Jul 25, 2018 at 7:54 AM, Paul Koning via cctalk <
> > cctalk@classiccmp.org> wrote:
> >
> >>> On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech <
> >> cct...@classiccmp.org> wrote:
> >>> Why don't you simply power it through an inverter that will output 60
> >> Hz, eventually even "down to" 120 V , true sine wave, of course ??? They
> >> are not that expensive by now.
> >>
> >> I wouldn't worry about "true sine wave".  That seems more of a marketing
> >> thing anyway, and motors don't care.  Just feed them with a variable
> >> frequency motor drive and all should be well.
> >>
> >>> And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR
> >> THE OPPOSITE, I do not recall  !!!, display a significant reduced life
> time.
> >>> I have to check which is which, but I know this is a question of
> >> saturated magnetic field. Better check first.
> >>
> >> That doesn't sound right.  If you run the frequency up high enough you
> >> might get into problems with magnetic materials not designed for it.
> And
> >> much lower probably gives you reduced torque.  But 50 vs. 60 Hz is a
> >> trivial difference for a motor, I can't see any reasons for that to
> cause
> >> trouble.  I routinely run my lathe at half frequency if not less, and it
> >> doesn't complain.
> >>
> > I'm not sure about motors, but 60 Hz power transformers can't handle as
> > high a maximum power (or current) when used for 50 Hz. The maximum power
> > has to be derated. Some transformers are specified/sold with a single
> power
> > specification for both 50 and 60 Hz use, which just means that the vendor
> > has built the necessary derating into even the 60 Hz specification.
> >
> > Some products were built using different transformers for 50 vs 60 Hz
> > models, and the 60 Hz models uses a transformer inadequate for 50 Hz
> > operation.
> >
> It has to do with the physics of flux linkages and saturation. Under
> sinusoidal operation, voltage is proportional to the product of maximum
> flux and frequency.  If you fix the voltage, in order to operate at 5/6
> of the nominal frequency you need a flux that is  6/5 the nominal one.
> This might not seem like much more flux, but due to the nonlinear
> magnetization characteristics,  the required magnetization current will
> not be 6/5 times the nominal current, but it could in fact be three
> times higher or even more, and highly distorted.
>
> Under-frequency and over-voltage can kill power transformers easily.
>
> A transformer designed to operate at 50 Hz will therefore have much more
> iron mass in its core, power and voltage being equal.  That's why in
> airplanes power is distributed at 400Hz; the transformers will be much
> lighter.
>
> carlos.
>
>
> --
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Anders Nelson via cctalk]

Omg finally I know why airplanes use 400Hz, thank you! Honestly that's been
on my mind for years.

=]

On Wed, Jul 25, 2018 at 2:06 PM Carlos E Murillo-Sanchez via cctalk <
cctalk@classiccmp.org> wrote:

> Eric Smith via cctalk wrote:
> > On Wed, Jul 25, 2018 at 7:54 AM, Paul Koning via cctalk <
> > cctalk@classiccmp.org> wrote:
> >
> >>> On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech <
> >> cct...@classiccmp.org> wrote:
> >>> Why don't you simply power it through an inverter that will output 60
> >> Hz, eventually even "down to" 120 V , true sine wave, of course ??? They
> >> are not that expensive by now.
> >>
> >> I wouldn't worry about "true sine wave".  That seems more of a marketing
> >> thing anyway, and motors don't care.  Just feed them with a variable
> >> frequency motor drive and all should be well.
> >>
> >>> And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR
> >> THE OPPOSITE, I do not recall  !!!, display a significant reduced life
> time.
> >>> I have to check which is which, but I know this is a question of
> >> saturated magnetic field. Better check first.
> >>
> >> That doesn't sound right.  If you run the frequency up high enough you
> >> might get into problems with magnetic materials not designed for it.
> And
> >> much lower probably gives you reduced torque.  But 50 vs. 60 Hz is a
> >> trivial difference for a motor, I can't see any reasons for that to
> cause
> >> trouble.  I routinely run my lathe at half frequency if not less, and it
> >> doesn't complain.
> >>
> > I'm not sure about motors, but 60 Hz power transformers can't handle as
> > high a maximum power (or current) when used for 50 Hz. The maximum power
> > has to be derated. Some transformers are specified/sold with a single
> power
> > specification for both 50 and 60 Hz use, which just means that the vendor
> > has built the necessary derating into even the 60 Hz specification.
> >
> > Some products were built using different transformers for 50 vs 60 Hz
> > models, and the 60 Hz models uses a transformer inadequate for 50 Hz
> > operation.
> >
> It has to do with the physics of flux linkages and saturation. Under
> sinusoidal operation, voltage is proportional to the product of maximum
> flux and frequency.  If you fix the voltage, in order to operate at 5/6
> of the nominal frequency you need a flux that is  6/5 the nominal one.
> This might not seem like much more flux, but due to the nonlinear
> magnetization characteristics,  the required magnetization current will
> not be 6/5 times the nominal current, but it could in fact be three
> times higher or even more, and highly distorted.
>
> Under-frequency and over-voltage can kill power transformers easily.
>
> A transformer designed to operate at 50 Hz will therefore have much more
> iron mass in its core, power and voltage being equal.  That's why in
> airplanes power is distributed at 400Hz; the transformers will be much
> lighter.
>
> carlos.
>
>
> --
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Mattis Lind via cctalk]

2018-07-26 6:21 GMT+02:00 Paul Anderson via cctalk :

> I can't find my IPB, but the maintenance manual shows there were both 50
> and 60 hz  versions made.
>
> I think I've shipped them overseas, but never modified them. I did ship a
> lot of RX02 drives overseas, and to properly convert them the pulleys,
> belts, and wiring harness had to be swapped. We were always on the lookout
> for parts. I still have a few different wiring harnesses around here
> somewhere.
>
> BA11-K conversions were also common. I still have interesting stories and
> parts about them.
>
> What gets me with the RK05 is how you can swap pulleys without swapping
> belts. A few products had pulleys with two grooves, one for 50, the other
> for 60. But you still needed a different belt.
>

You need to move the motor to a new position in the RK05. The drive is
already prepared for all this. It is just the pulley, moving the motor and
the 220VAC jumper that is needed.

/Mattis


>
> Paul
>
> On Wed, Jul 25, 2018 at 10:32 PM, Tony Duell via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > > There are, however, DEC products other than the RK05 which had
> different
> > > transformers for 50 Hz and 60 Hz. For example, the H771 power supply
> used
> > > in the RX01 and RX02. There were three H771 models, The H771A for
> 90-132
> > > VAC 60 Hz, The H771C for 90-132 VAC 50 Hz, and the H771D for 180-264
> VAC
> > 50
> > > Hz. The H771A uses a transformer rated for 60 Hz. The H771C and H771D
> > both
> > > use the same 50 Hz rated transformer, with different wiring. The H771C
> > and
> > > H771D also require one of two different wiring harnesses to cover the
> > > entire mains voltage range, e.g., 90-120 VAC vs 100-132 VAC for the
> > H771C,
> > > or twice those voltages for the H771D.
> >
> > IIRC that's a ferroresonant transformer (with a capacitor to resonate one
> > of the
> > windings to a harmonic of the power line frequency), so it's not
> > surprising it has
> > to be changed for 50Hz or 60Hz input.
> >
> > -tony
> >
>

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Anderson via cctalk]

I can't find my IPB, but the maintenance manual shows there were both 50
and 60 hz  versions made.

I think I've shipped them overseas, but never modified them. I did ship a
lot of RX02 drives overseas, and to properly convert them the pulleys,
belts, and wiring harness had to be swapped. We were always on the lookout
for parts. I still have a few different wiring harnesses around here
somewhere.

BA11-K conversions were also common. I still have interesting stories and
parts about them.

What gets me with the RK05 is how you can swap pulleys without swapping
belts. A few products had pulleys with two grooves, one for 50, the other
for 60. But you still needed a different belt.

Paul

On Wed, Jul 25, 2018 at 10:32 PM, Tony Duell via cctalk <
cctalk@classiccmp.org> wrote:

> > There are, however, DEC products other than the RK05 which had different
> > transformers for 50 Hz and 60 Hz. For example, the H771 power supply used
> > in the RX01 and RX02. There were three H771 models, The H771A for 90-132
> > VAC 60 Hz, The H771C for 90-132 VAC 50 Hz, and the H771D for 180-264 VAC
> 50
> > Hz. The H771A uses a transformer rated for 60 Hz. The H771C and H771D
> both
> > use the same 50 Hz rated transformer, with different wiring. The H771C
> and
> > H771D also require one of two different wiring harnesses to cover the
> > entire mains voltage range, e.g., 90-120 VAC vs 100-132 VAC for the
> H771C,
> > or twice those voltages for the H771D.
>
> IIRC that's a ferroresonant transformer (with a capacitor to resonate one
> of the
> windings to a harmonic of the power line frequency), so it's not
> surprising it has
> to be changed for 50Hz or 60Hz input.
>
> -tony
>

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Tony Duell via cctalk]

> There are, however, DEC products other than the RK05 which had different
> transformers for 50 Hz and 60 Hz. For example, the H771 power supply used
> in the RX01 and RX02. There were three H771 models, The H771A for 90-132
> VAC 60 Hz, The H771C for 90-132 VAC 50 Hz, and the H771D for 180-264 VAC 50
> Hz. The H771A uses a transformer rated for 60 Hz. The H771C and H771D both
> use the same 50 Hz rated transformer, with different wiring. The H771C and
> H771D also require one of two different wiring harnesses to cover the
> entire mains voltage range, e.g., 90-120 VAC vs 100-132 VAC for the H771C,
> or twice those voltages for the H771D.

IIRC that's a ferroresonant transformer (with a capacitor to resonate one of the
windings to a harmonic of the power line frequency), so it's not
surprising it has
to be changed for 50Hz or 60Hz input.

-tony

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Eric Smith via cctalk]

On Wed, Jul 25, 2018 at 12:17 PM, Tony Duell  wrote:

> On Wed, Jul 25, 2018 at 5:48 PM, Eric Smith via cctalk
> > Some products were built using different transformers for 50 vs 60 Hz
> > models, and the 60 Hz models uses a transformer inadequate for 50 Hz
> > operation.
>
> This may well be true (I think it is), but the original question was about
> a
> particular device, the DEC RK05 disk drive. According to the maintenance
> manual (on bitsavers), the coversion between 50Hz and 60Hz involves
> changing
> the motor pulley. No comment about replacing the motor, the start
> capacitor,
> or anything else.
>

Right. I was just responding to a later, general comment about motors.
There are, however, DEC products other than the RK05 which had different
transformers for 50 Hz and 60 Hz. For example, the H771 power supply used
in the RX01 and RX02. There were three H771 models, The H771A for 90-132
VAC 60 Hz, The H771C for 90-132 VAC 50 Hz, and the H771D for 180-264 VAC 50
Hz. The H771A uses a transformer rated for 60 Hz. The H771C and H771D both
use the same 50 Hz rated transformer, with different wiring. The H771C and
H771D also require one of two different wiring harnesses to cover the
entire mains voltage range, e.g., 90-120 VAC vs 100-132 VAC for the H771C,
or twice those voltages for the H771D.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Guy Sotomayor Jr via cctalk]

> On Jul 25, 2018, at 11:17 AM, Tony Duell via cctalk  
> wrote:
> 
> On Wed, Jul 25, 2018 at 5:48 PM, Eric Smith via cctalk
>  wrote:
> 
>> I'm not sure about motors, but 60 Hz power transformers can't handle as
>> high a maximum power (or current) when used for 50 Hz. The maximum power
>> has to be derated. Some transformers are specified/sold with a single power
>> specification for both 50 and 60 Hz use, which just means that the vendor
>> has built the necessary derating into even the 60 Hz specification.
>> 
>> Some products were built using different transformers for 50 vs 60 Hz
>> models, and the 60 Hz models uses a transformer inadequate for 50 Hz
>> operation.
> 
> This may well be true (I think it is), but the original question was about a
> particular device, the DEC RK05 disk drive. According to the maintenance
> manual (on bitsavers), the coversion between 50Hz and 60Hz involves changing
> the motor pulley. No comment about replacing the motor, the start capacitor,
> or anything else.
> 
> Does anyone have an RK05 IPB (Illustrated Parts Breakdown) manual? It would
> be interesting to see if there are different part numbers for the motor (start
> capacitor, blower...) for 50Hz and 60Hz versions.
> 
> Going back to a much earlier comment, I think this pulley is something that
> would be a lot easier to turn (on a lathe) rather than 3D print.

A while ago (can’t recall how many years), I acquired a number of 50Hz RK05’s.
Since I live in a 60Hz country, getting the drives to work simply involved 
changing
the pulley from the 50Hz version to the 60Hz version and changing the voltage
jumpers (the drives have worked fine after that change).  I believe that the 
switch
over is documented somewhere…but it’s been *way* too long since I did it.

As far as I recall, the pulleys have the frequency stamped on them.

For the OP who started this thread.  Yes, I still have the 50Hz pulleys 
*somewhere*
but at this point they're not easy to find as they are packed in a tote in the 
basement
of my shop (which is packed floor to ceiling with boxes and totes…there isn’t 
even
an isle to walk around in…just a small area that you can almost turn around in).

TTFN - Guy

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Tony Duell via cctalk]

On Wed, Jul 25, 2018 at 5:48 PM, Eric Smith via cctalk
 wrote:

> I'm not sure about motors, but 60 Hz power transformers can't handle as
> high a maximum power (or current) when used for 50 Hz. The maximum power
> has to be derated. Some transformers are specified/sold with a single power
> specification for both 50 and 60 Hz use, which just means that the vendor
> has built the necessary derating into even the 60 Hz specification.
>
> Some products were built using different transformers for 50 vs 60 Hz
> models, and the 60 Hz models uses a transformer inadequate for 50 Hz
> operation.

This may well be true (I think it is), but the original question was about a
particular device, the DEC RK05 disk drive. According to the maintenance
manual (on bitsavers), the coversion between 50Hz and 60Hz involves changing
the motor pulley. No comment about replacing the motor, the start capacitor,
or anything else.

Does anyone have an RK05 IPB (Illustrated Parts Breakdown) manual? It would
be interesting to see if there are different part numbers for the motor (start
capacitor, blower...) for 50Hz and 60Hz versions.

Going back to a much earlier comment, I think this pulley is something that
would be a lot easier to turn (on a lathe) rather than 3D print.

-tony

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Carlos E Murillo-Sanchez via cctalk]

Eric Smith via cctalk wrote:

On Wed, Jul 25, 2018 at 7:54 AM, Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:


On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech <

cct...@classiccmp.org> wrote:

Why don't you simply power it through an inverter that will output 60

Hz, eventually even "down to" 120 V , true sine wave, of course ??? They
are not that expensive by now.

I wouldn't worry about "true sine wave".  That seems more of a marketing
thing anyway, and motors don't care.  Just feed them with a variable
frequency motor drive and all should be well.


And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR

THE OPPOSITE, I do not recall  !!!, display a significant reduced life time.

I have to check which is which, but I know this is a question of

saturated magnetic field. Better check first.

That doesn't sound right.  If you run the frequency up high enough you
might get into problems with magnetic materials not designed for it.  And
much lower probably gives you reduced torque.  But 50 vs. 60 Hz is a
trivial difference for a motor, I can't see any reasons for that to cause
trouble.  I routinely run my lathe at half frequency if not less, and it
doesn't complain.


I'm not sure about motors, but 60 Hz power transformers can't handle as
high a maximum power (or current) when used for 50 Hz. The maximum power
has to be derated. Some transformers are specified/sold with a single power
specification for both 50 and 60 Hz use, which just means that the vendor
has built the necessary derating into even the 60 Hz specification.

Some products were built using different transformers for 50 vs 60 Hz
models, and the 60 Hz models uses a transformer inadequate for 50 Hz
operation.

It has to do with the physics of flux linkages and saturation. Under 
sinusoidal operation, voltage is proportional to the product of maximum 
flux and frequency.  If you fix the voltage, in order to operate at 5/6 
of the nominal frequency you need a flux that is  6/5 the nominal one.  
This might not seem like much more flux, but due to the nonlinear 
magnetization characteristics,  the required magnetization current will 
not be 6/5 times the nominal current, but it could in fact be three 
times higher or even more, and highly distorted.


Under-frequency and over-voltage can kill power transformers easily.

A transformer designed to operate at 50 Hz will therefore have much more 
iron mass in its core, power and voltage being equal.  That's why in 
airplanes power is distributed at 400Hz; the transformers will be much 
lighter.


carlos.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Eric Smith via cctalk]

On Wed, Jul 25, 2018 at 7:54 AM, Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:

> > On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech <
> cct...@classiccmp.org> wrote:
> >
> > Why don't you simply power it through an inverter that will output 60
> Hz, eventually even "down to" 120 V , true sine wave, of course ??? They
> are not that expensive by now.
>
> I wouldn't worry about "true sine wave".  That seems more of a marketing
> thing anyway, and motors don't care.  Just feed them with a variable
> frequency motor drive and all should be well.
>
> > And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR
> THE OPPOSITE, I do not recall  !!!, display a significant reduced life time.
> > I have to check which is which, but I know this is a question of
> saturated magnetic field. Better check first.
>
> That doesn't sound right.  If you run the frequency up high enough you
> might get into problems with magnetic materials not designed for it.  And
> much lower probably gives you reduced torque.  But 50 vs. 60 Hz is a
> trivial difference for a motor, I can't see any reasons for that to cause
> trouble.  I routinely run my lathe at half frequency if not less, and it
> doesn't complain.
>

I'm not sure about motors, but 60 Hz power transformers can't handle as
high a maximum power (or current) when used for 50 Hz. The maximum power
has to be derated. Some transformers are specified/sold with a single power
specification for both 50 and 60 Hz use, which just means that the vendor
has built the necessary derating into even the 60 Hz specification.

Some products were built using different transformers for 50 vs 60 Hz
models, and the 60 Hz models uses a transformer inadequate for 50 Hz
operation.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning via cctalk]

> On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech  
> wrote:
> 
> Why don't you simply power it through an inverter that will output 60 Hz, 
> eventually even "down to" 120 V , true sine wave, of course ??? They are not 
> that expensive by now. 

I wouldn't worry about "true sine wave".  That seems more of a marketing thing 
anyway, and motors don't care.  Just feed them with a variable frequency motor 
drive and all should be well.

> And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR THE 
> OPPOSITE, I do not recall  !!!, display a significant reduced life time.
> I have to check which is which, but I know this is a question of saturated 
> magnetic field. Better check first.

That doesn't sound right.  If you run the frequency up high enough you might 
get into problems with magnetic materials not designed for it.  And much lower 
probably gives you reduced torque.  But 50 vs. 60 Hz is a trivial difference 
for a motor, I can't see any reasons for that to cause trouble.  I routinely 
run my lathe at half frequency if not less, and it doesn't complain.

paul

RK05 spindle pulleys - trade 50Hz vs 60Hz?

[GerardCJAT via cctalk]

Why don't you simply power it through an inverter that will output 60 Hz, 
eventually even "down to" 120 V , true sine wave, of course ??? They are not 
that expensive by now. 
And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR THE 
OPPOSITE, I do not recall  !!!, display a significant reduced life time.
I have to check which is which, but I know this is a question of saturated 
magnetic field. Better check first.

Re: RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Steve Malikoff via cctalk]

Mattis said
> I have two RK05J-AA as part of a system that I guess has been imported used
> form the US. A DC-10 simulator.
>
> The only difference is the pulley, the motor position and a 230 / 115 V
> jumper inside.
>
> Is there anyone in 60Hz land that has the opposite problem and want to
> trade two spindle pulleys?
>
> The good thing for me that I would guess that it possible to use a lathe to
> get the diameter down to the correct 50Hz diameter. On the other hand going
> from 50Hz to 60 Hz is tougher...
>
> Then there is a PC05 that has the wrong number of grooves on the motor
> pulley. Apparently it should be 16 instead of 20.
>
> Now in 50Hz land the only difference is that the punch would be slower than
> it should be. Using a 50Hz punch in 60Hz area might get you into problems,
> so maybe there is someone here as well that want to do a trade?

I relish these sorts of problems. If you have a digital caliper to take some
measurements and could sketch it up roughly, I can draw it up in CAD. Photos
would help determine how complicated the machining job would be.

I wonder if a 3D printed one might work? A pulley couldn't be too challenging
depending on how it is fixed to the spindle. If by grubscrews then that would
require a metal boss or flange as the plastic would not likely be be strong
enough for grubscrew threads to withstand the torque. However if it's just 
clamped
with a large axial nut and washer on the spindle it could be ok.

Of course if you can trade for the right ones, that would be best of all :)

Steve.

RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Mattis Lind via cctalk]

Hello!

I have two RK05J-AA as part of a system that I guess has been imported used
form the US. A DC-10 simulator.

The only difference is the pulley, the motor position and a 230 / 115 V
jumper inside.

Is there anyone in 60Hz land that has the opposite problem and want to
trade two spindle pulleys?

The good thing for me that I would guess that it possible to use a lathe to
get the diameter down to the correct 50Hz diameter. On the other hand going
from 50Hz to 60 Hz is tougher...

Then there is a PC05 that has the wrong number of grooves on the motor
pulley. Apparently it should be 16 instead of 20.

Now in 50Hz land the only difference is that the punch would be slower than
it should be. Using a 50Hz punch in 60Hz area might get you into problems,
so maybe there is someone here as well that want to do a trade?

/Mattis