High voltage transformer for deflection of electron beams

A high voltage transformer is provided for the voltage employed in the line deflection of an electron beam in a television receiver. The secondary high voltage winding is inserted into a case via an opening running parallel to the axis of the primary and secondary winding and is disposed in the case separate from the primary winding and is surrounded by a cast plastic resin. Preferably, the secondary winding body snaps into elastically supported protrusions disposed at the case. The plastic resin is filled into position through said opening. The high voltage connection is immersed into the plastic resin and is then led outwardly.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a transformer generating a voltage for the 
deflection of electron beams, for the generation of a high deflection 
voltage, as well as for a voltage for focussing the electron beams in a 
picture tube of a television receiver. 
2. Brief Description of the Background of the Invention Including Prior Art 
Transformers are employed to effect a the change in voltage in alternating 
electrical power sources. The primary winding as well as some auxiliary 
windings are conventionally disposed on a first winding form and a high 
voltage winding for the generation of a high voltage is located at a 
second winding form disposed concentrically relative to the first winding 
form. The high voltage winding is fixed in position by casting around its 
a plastic resin. 
Such transformers are known under the designation diode-split-transformer. 
They comprise a primary winding with several auxiliary windings for the 
generation of several operating voltages. The windings are provided as 
aluminum foils with interposed insulating foils. Wire pieces protruding 
beyond the foil edge are welded on at the tapping points cross to the 
winding and the wire pieces run parallel to the axial direction of the 
winding form and lead at the end to a connector strip terminal. 
The winding form providing the high voltage is subdivided into several 
winding chambers such that the winding can be subdivided into numerous 
winding sections. Diodes are connected between the winding sections such 
that the windings are connected in series via the diodes. High voltages 
result in connection with the winding length and winding capacity, which 
can be taken as high voltage or, respectively, focussing voltage for the 
picture tube of a television receiver. The two winding bodies are 
coaxially inserted and are supported in a case, where they are supported 
high voltage proof by filling in of an epoxy resin. The casting mass is 
filled into the case in parallel to the winding form axis from the 
connection side of the wires at the axial end of the winding form. The 
connections for the high voltage and the focussing voltage are led through 
the wall of the case near the opposite end of the case. In this connection 
the openings for the passage of the winding connections after the 
insertion of the connection wires have to be sealed carefully before the 
filling in of the synthetic plastic resin. This results in additional work 
expenditures as well as in a relatively high expenditure in costs and 
materials. 
SUMMARY OF THE INVENTION 
1. Purposes of the Invention 
It is an object of the present invention to provide a simplified 
transformer for providing high voltages for electron beam control. 
It is a further object of the present invention to provide a transformer 
where the high voltage wire connections are disposed remote from the 
magnetic core. 
It is another object of the present invention to provide a simpler and less 
expensive method for the production of improved high voltage transformers. 
These and other objects and advantages of the present invention will become 
evident from the description which follows. 
2. Brief Description of the Invention 
The present invention provides a transformer for generating a high voltage 
for control of an electron beam which comprises a second winding body 
including a secondary winding for providing a high voltage, a case 
surrounding the second winding and having an opening in an end wall 
located at a plane disposed parallel to the axis of the secondary winding 
for allowing the insertion of the second winding body into the case 
through the opening, an electrical connection for the second winding body 
and running through said opening, a first winding body comprising a 
primary winding disposed concentrically to the second winding body, and a 
cast of synthetic resin disposed in the case and surrounding the second 
winding body. 
The first winding body can further comprise auxiliary windings. The first 
winding body can remain with its windings outside of the cast area. The 
first winding body is preferably inserted into the case and coaxially into 
the second winding body via the opening disposed in the wall of the case. 
Inwardly directed protrusions can be disposed at the edges of the openings 
in the end walls of the case and can provide a catch-locked position for 
the second winding body. Preferably, the inwardly directed protrusions are 
provided such that they act like a seal for the liquid plastic resins 
during filling of the case. 
Electrical connections of the second winding body for the focussing voltage 
and the screen grid voltage can be furnished, which electrical connections 
are led outwardly through the plastic resin and which are adapted to be 
connected to a potentiometer unit. A ferrite core can be disposed inside 
of the primary winding. The ferrite core can comprise two sections, which 
are inserted into the primary winding from opposite sides in axial 
direction and which comprise yoke sections running outside of the case and 
joining together to provide a substantially continuous magnetic flux. 
Preferably, the side walls are provided with the inside protrusions near 
the position of second winding for locking the second winding in position, 
which protrusions are elastically supported to allow for motion during the 
snap-in type insertion of the second winding body. 
The synthetic resin can be a member of the group consisting of epoxide, 
polyvinyl chloride, polyethylene, polypropylene, crosslinked polyethylene, 
polytetrafluoroethylene, fluorinated ethylene propylene, polyvinyliden 
fluoride, silicone rubber, polychloroprene rubber, butyl rubber, 
polyurethane, polyamide, polyimide, polyester, polyalkene, polysulfone, 
and mixtures thereof. Preferably, the synthetic resin has a loss factor at 
1000 Hertz of less than about 0.02 and preferably the dielectric strength 
of the synthetic resin is at least about 400 volts per millimeter. 
There is also provided a method for the production of the high voltage 
transformers which comprises producing a second winding body to provide a 
high voltage, molding a case for supporting the second winding body, which 
has a side opening, inserting the second winding body into the case 
through the side opening, and filling the area around the second winding 
body inside the case with a synthetic resin material. 
A first winding body can be inserted into the case and coaxially into the 
second winding body via an opening disposed in the wall of the case, and 
the first winding body further can include auxiliary windings. A magnetic 
yoke with a ferrite core can be inserted into the primary winding body, 
and preferably the magnetic yoke comprises two sections, which are 
inserted into the primary winding from opposite sides in axial direction 
and which comprise yoke sections running outside of the case and joining 
together to provide a substantially continuous magnetic flux. 
The second winding body can be snapped-in over inwardly directed 
protrusions disposed at the edges of the openings in the end walls of the 
case near the position of second winding for locking the second winding in 
position, which protrusions are elastically supported to allow for motion 
during the snap-in type insertion of the second winding body. Electrical 
connections of the second winding body for the focussing voltage the 
screen grid voltage can be led outwardly through the synthetic plastic 
resin such that they can serve to be connected to a potentiometer unit. 
The case can be filled with liquid synthetic plastic resin while the 
inwardly directed protrusions act like a seal for the liquid plastic resin 
during filling of the case. 
The novel features which are considered as characteristic for the invention 
are set forth in the appended claims. The invention itself, however, both 
as to its construction and its method of operation, together with 
additional objects and advantages thereof, will be best understood from 
the following description of specific embodiments when read in connection 
with the accompanying drawing.

DESCRIPTION OF INVENTION AND PREFERRED EMBODIMENT 
In accordance with the present invention there is provided a high voltage 
transformer for providing voltage for electron beam control, where the 
case 1 has an opening 2 in a plane parallel to the winding form axes 4. A 
second winding form 3 is inserted into the case 1 through the opening 5 
and then synthetic plastic resin 13 can be filled into the case 1 through 
the opening 5. An electrical connection 21 of the winding applied to the 
winding form 3 is embedded in the plastic resin and led outward via the 
case opening 5. 
The first winding form 2 can remain outside of the cast area with its 
windings and can be inserted through an opening 15 disposed in a side wall 
7 of the case coaxially to the second winding body 3. The openings 14, 15 
disposed in the side walls of the case are provided at their edges with 
inwardly directed protrusions 8, into which the second winding form 3 is 
snapped in. The snap-in attachment and connection can be furnished such 
that it provides a seal for the liquid synthetic plastic resin 13 during 
the filling process. Electrical connections for the focussing voltage and 
for the screen grid voltage can start at the winding form 3 and pass 
through the synthetic plastic resin to the outside and a potentiometer 
unit 19, 20 can be plugged onto these connections. 
The case 1 is furnished such as to support the winding forms 2 and 3. The 
winding form 2 comprises a primary winding as well as several auxiliary 
windings. The winding form 3 supports the high voltage winding, which 
provides the anode voltage for the television picture tube and the 
focussing voltage as well as the screen grid voltage. An opening 5 is 
provided in the case 1 in a plane disposed in parallel to the joint axis 4 
of the two winding forms 2 and 3. The winding form 3 can be inserted 
through this opening 5. The winding form 3 snaps into circular protrusions 
8 coaxial to the axis 4 and disposed at the side walls 6 and 7 of the case 
1. A sealing is furnished based on the elasticity of the side walls of the 
case 1, where the inclined and bevelled circular edges 11 and 12 at the 
flanges 9 and 10 of the winding form 3 are pressed against the protrusions 
8. 
After the winding form 3 with its windings is snapped into the case 1, the 
synthetic plastic resin 13 can be filled into the case 1 through the 
opening 5, where the synthetic plastic resin 13 surrounds the connection 
wire 21 led upwardly for the high voltage. Thus an additional opening to 
be sealed is not required for this high voltage connection. The winding 
body 2 for the primary winding is slid coaxially to the axis 4 into the 
case 1 through an opening 15 of the side wall 7 into a space, which is not 
filled by the synthetic plastic resin. The winding body 2 for the primary 
winding is disposed in the opposite side wall 6 of the case 1. 
Finally, the ferrite U-core 16 is slid into the winding body 2 by passing 
through the openings 14 or 15 disposed in the side walls 6 and 7. The case 
1 with its side walls 6 and 7 and supported by a support frame is 
tensioned such inwardly in the direction of the axis 4 during the filling 
in of the synthetic plastic resin that the circular protrusions 8 at the 
side walls are pressed against the edges 11 and 12 and thus a sealing is 
achieved, as is shown in the enlarged view of FIG. 1a. Connections 17 and 
18 for the focussing voltage and the screen grid voltage are fed outwardly 
from the high voltage winding disposed on the winding body 3 through the 
synthetic plastic resin 13. The setting potentiometers 19 and 20 required 
for setting the recited voltages are advantageously provided as a unit 
with plug-in connections. Then the unit described can be adapted to 
various tube concepts by plugging in a corresponding potentiometer unit. 
The unit described entails the advantage that the winding form 2 can be 
exchanged and this way depending on the picture tube type a winding form 2 
can be inserted specifically matching the picture tube type. 
FIG. 2 shows a perspective exploded view of the components employed. The 
winding from 3 can be substantially of cylindrical shape and the partial 
end flanges for providing a seal can be recognized. The two side walls of 
the case 1 can be of different configuration as shown. The primary winding 
form can be provided with an extension to allow for easy insertion into 
the openings of the case. The inner winding form can be provided with 
gripping provisions to allow a firm insertion. The magnetic core can 
comprise two equal parts where each part is inserted from one side of the 
case. Preferably the part section inserted into the winding form 2 is of 
cylindrical shape and the outside parts providing a closure of the 
magnetic circuit are preferably of rectangular configuration. 
The case and the support parts of the winding forms can be made from a 
plastic material which has a low dielectric loss and a high electrical 
insulation strength. The windings are made from a metal of high metallic 
conductivity such as aluminum or copper. The magnetic core can be of a 
ferrite or other soft magnetic material. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
transformer system configurations and high voltage generating procedures 
differing from the types described above. 
While the invention has been illustrated and described as embodied in the 
context of a high voltage transformer for deflection of electron beams, it 
is not intended to be limited to the details shown, since various 
modifications and structural changes may be made without departing in any 
way from the spirit of the present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention. 
What is claimed as new and desired to be protected by Letters Patent is set 
forth in the appended claims.