IEC 60139:2019 pdf download

IEC 60139-2019 pdf download.Preparation of outline drawings forcathode-ray tubes, their components,connections and gauges.
3.1.24
Z-point
reference point on the external surface of the panel along the diagonal
3.2 Units and symbols
Units, graphical symbols and letter symbols should, wherever possible, be taken from the publications listed in clause 2 of this standard.
When further items are required they should be derived in accordance with the principles of these publications.
4 General requirements
This standard prescribes the outline drawing views and the dimensions and descriptions required for documenting a generic CRT design. The recommendations for each drawing are specified in 5.1, 5.2, 5.3 and specimen drawings are shown in figure 1 through figure 18.
If the phosphor screen extent is hidden by the band, the degree of vignetting should be indicated on one of the views.
4.1 Required views
In general, the views required to describe a rectangular CRT shall be the front, top. side and diagonal. When the implosion protection and mounting system is integral to the tube, a second front view and the mounting lug outline drawing may be included.
The components of the CRT (panel, funnel, base, reference line gauge, beam clearance gauge and ancillary equipment) are part of the outline drawing information.
Monochrome and projection CRTs may not require all of the entries. If the dimensions mentioned in the tabular layout below the specimen outline drawings are applicable to the tube to be described, they shall be given on the outline sheet.
If the CRT has appendages or features not described in this standard, additional views shall be included to fully describe them.
4.2 General rules and guidelines for the outline drawings
The specific guidelines for each drawing have been chosen based on balancing the amount of detail and quantity of dimensions on each drawing. If future designs require more or less detail on certain views, it is appropriate to relocate dimensional information to other views so long as the information is retained in an unambiguous manner.
The drawing shall show all dimensions necessary to assure clearances and mating with auxiliary accessories.
Drawings need not be drawn to scale, but they shall be roughly in proportion and, where necessary for clarity, an enlarged detail drawing shall be used.
Angles shall be indicated as follows:
a) by quoting the value in degrees and minutes and seconds or in decimal notation. Where this is not practical, the value may be quoted in fractions of degrees:
b) where it is selfevident that a number of angles are of equal value, the value of only one of those angles shall be quoted.
5 Specific requirements
5.1 Specific requirements of CRT outline drawings
The following views and related dimensions shall be included where appropriate. Where it is possible to combine this data into fewer views, this is permissible. Where additional types of dimensions are deemed useful, they may be included.
Each of the following subclauses identities the suggested data for a drawing. Data can be shown on other drawings if it is more convenient.
5.1.1 Front view of the CRT
The front view shall provide values for the tollowin9 list of dimensions, as shown in figure 1:
• dimension of the CRT including mounting system:
• clearance for the band junction when positioned on the minor or major axis:
• distances between the centres of the CRT mounting holes;
• design aspect ratio;
• dimensions of the minimum, nominal and maximum useful phosphor screen;
• curvature of the useful phosphor (if not straight):
• location of the Z•point
• electron gun positions (designated R. G, B):
• clock position of the anode connector.
5.1.2 Top view of the CRT
The top (or bottom) view shall show the anode connector and provide values for the following list of dimensions, as shown in figure 2:
• neck outside diameter;
• location for the convergence device:
• area for reliable contact to the outer conductive coating;
• major axis dimensions of the band;
• base and anode connector type designations.