Improvements in or relating to the Regulation of Dynamo Electric Machines.
Year: 1889

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to the Regulation of Dynamo Electric
Machines.
I, WILLIAM MORRIS MORDEY of the Victoria Works, Belvedere Road, Lambeth in
theCounty of Surrey, Electrician,do hereby declare the nature of this invention to be
as follows:-
This invention has for itsobjectan improved method ormeans for renderingdynamos
independent of variations of speed.
Hitherto, so far as I am aware, all the methods used or proposed for compensating
for variations or irregularities of speed have depended upon devices which act only
after such variations have occurred and haveproduced some correspondingirregularity
in the output of the dynamo. That is to say.their action depends upon avariation of
speed occurring, the effect of which they then more or less perfectly rectify.
The present invention has reference to an improved method of and means for
producing a regulation which shall be coincident with, and shall prevent the effect of
such change of speed.
As an addition to the dynamo which is subject to variations of speed, and which is
hereinafter called the main generator. I employ, according to this invention, a small
dynamo of any suitable kind, both machines being driven by the same motor and
therefore subject to the same degree of variation. The additional dynamo is made
to produce an opposing or partially demagnetising effect upon the fields of the main
generator. At the normal speed the differential value of the main generator field
currents is that of the normal field required. When a rise or fall of speed takes place
the demagnetising current of the additional dynamo increases or decreases so as to
neutralise the effect on the main generator of the variation of speed.
In carrying out this invention a separate coil may be wound on the field magnet of
the dynamo which it is desired to control, this coil being connected to the additional
dynamo; or the additional dynamo may be connected to the whole or a part of the
ordinary exciting circuit so as to weaken the exciting current.
Inthe case of separately excitedmachines the additional dynamo is preferablymade
to act on thefields of the separate exciter, thus indirectly.instead of directly, affecting
the larger fields of the main generator.
The additional dynamo is preferably series wound and is designed to run at such a
normal speed that the variation of its current follows in the required manner the
variations of speed of the motor.
To prevent the effect of any accidental or other stoppage of the demagnetising
current an electromagnet may be arranged in the demagnetising circuit to control a
resistance or additional winding placed in the main magnetising circuit. On the
stoppage of thedemagnetising current the electromagnet iscaused to actand to reduce
the effective magnetising current to the normal amount.
Dated this Sth day of January 1889
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to the Regulation of Dynamo Electric
Machines.
I, WILLIAM MORRIS MORDEY, of the Victoria Works, Belvedere Road, Lambeth, in
the County of Surrey, Electrician, do hereby declare the nature of this invention and
[Price Sd.]

page_text: in what manner the same is to be performed, to be particularly described and ascer--
tained in and by the following statement:--
This invention has for its object an improved method or means for rendering
dynamos independent of variations of speed.
Hitherto, so far as I am aware, all the methods used or proposed for compensating
for variations or irregularities of speed have depended upon devices which act only
after such variations have occurredandhave produced some corresponding irregularity
in the out-put of the dynamo. That is to say, their action depends upon a variation of
speed occurring. the effect of which they then more or less perfectly rectify.
The present invention has reference to an improved method of and means for pro-
ducing a regulation whichshall be coincident with, andshall prevent the effect of such
change of speed.
As an addition to the dynamo which is subject to variations of speed, and which is
hereinafter called the main generator, I employ, according to this invention, a small
dynamo of any suitable kind, both machines being driven by the same motor and
therefore subject to the same degree of variation. The additional dynamo is made
to produce an opposing or partially demagnetising effect upon the fields of the main
generator. At the normal speed the differential value of the main generator field
currents is that of the normal field required. When a rise or fall of speed takes place
the demaguetising current of the additional dynamo increases or decreases so as to
neutralize the effect on the main generator of the variation of speed.
In carrying out this invention a separate coil may be wound on the field magnet of
the dynamo which it is desired to control, this coil being connected to the additional
dynamo; or the additional dynamo may be connected to the whole or a part of the
ordinary exciting circuit so as to weaken the exciting current.
Inthe case of separately excitedmachinesthe additional dynamo is preferablymade
to act onthe fields of the separate exciter, thus indirectly, instead of directly, affecting
the larger fields of the main generator.
The additional dynamo is preferably series wound, and is designed to run at such a
normal speed that the variation of its current follows in the required manuer the
variations of speed of the motor.
To prevent the effect of any accidental or other stoppage of the demagnetising
current an electromagnet may be arranged in the demagnetising circuit to control a
resistance or additional winding placed in the main magnetising circuit. On the
stoppage of the demagnetising current the electromagnet is caused to act and to
reduce the effective maguetising current to the normal amount.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. In connection with and for the regulation of a dynamo subject to a variable
speed, the use of an additional dynamo.subject to the same degree of speed variation:
and arranged to partly oppose or partly neutralize the magnetic excitation of the
first mentioned dynamo.
2. In connection with a separately excited machine. such, for instance, as an
alternator, the use for the purpose of regulation, of an additional dynamo connected
either to the exciter, as in claim 1, or directly to the separately excited machine.
3. In combination witheither of the arrangements claimed above, in claims 1 and 2,
the use of an electromagnet arranged to reduce the effective magnetisation to the
normal amount, in the event of a stoppage of the opposing or demagnetising current,
substantially as described.
Dated this 7th der of Antahan 1000
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.