Miniature Christmas light sets changed over the years to adapt to stricter safety standards.
By knowing this you can determine when your set was made.
Miniature Christmas light sets changed over the years to adapt to stricter
safety standards.
By knowing this you can determine when your set was made.
Start by examining the plug.
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| A - Non fused pre 1977. | B - Fusible link 1977 - 1990. | C - Replaceable fuses post 1987. (Roll cursor over photo) |
Photo A shows a non fused plug used prior to 1977 marked "15A 125V JAPAN".
This type of plug was used on miniature light sets before fuse protection was
required.
Photo B shows a fusible link plug used from 1977 to present, mostly on the
cheap sets. It is marked
"Current rating 1A, fuse rating 3A, 125V"
On this type of plug there is no door to access the fuses. That's because there
are two non replaceable fusible links inside the plug.
A fusible link is a short length of fuse wire inside the plug that provides over
current protection.
Photo C shows the now standard plug with replaceable fuses, used from 1987 to
present .
This plug is marked "use only 3A max 125V fuse". Roll your cursor over the photo
to open the fuse door.
Inside this plug are two replaceable 3.5 millimeter diameter by 10 millimeter
micro fuses, typically 3 amps.
At the same time Underwriters labs introduced the silver holographic
certification tag. The hologram is visible in blue.
Now examine the sockets
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Wire wrapped contact |
Crimped contact |
The picture on the left shows an old style socket with the wire simply wrapped around the contact, which is then inserted into the socket. This design is typical of sets from Taiwan sold before 1977.
The picture on the right shows a socket with crimped contact. This was required due to safety regulations that specified that the wire and insulation be solidly attached to the contact. The contact is also barbed, or shaped so it cannot easily come out of the socket.
Now examine the Bulbs.
The design of the bulbs also changed over the years. The bulb at left is an old school bulb, with the filament strung horizontally and formed into an arch. The problem with this design is that the filament would sometimes kink, as seen in the center bulb. This resulted in reduced light output, hot spots, and shortened life for the other bulbs in the string.
The bulb at right is a modern design introduced after 1987 with the filament strung lengthwise. This solves the previously mentioned problems.
Here are some more tips to help in dating the vintage of a set.
ZIP codes were introduced in
1963 and the ZIP+4 code in 1983 for decorations sold in the U.S.A.
U.P.C. bar codes were invented in 1973 and
introduced in 1974 but did not gain widespread use until a few years later.
Source : Wikipedia
Bulb base identification.
Miniature Christmas light bulbs were made in a variety of base
designs over the years.
The chart below identifies the ones I have come across.
| 1/4 inch wedge base. This is the most common base style in use. The 1/4 inch diameter refers to the round part of the base that enters the socket. |
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| 7 Millimeter wedge base. Used on sets made to metric standards, it's slightly larger than the 1/4 inch size shown above. |
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| 7 Millimeter wedge base with locking tab. The tab keeps the bulb from coming loose from the socket. |
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| Italian lights by Kurt S. Adler. Used on "Fairy Lights" made in Italy this style is smaller than the typical base at 5.5 millimeters, or 7/32 inch in diameter, with an oval shaped contact section. The entire bulb is only 24 millimeters, or 15/16 inch long. |
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| Santa's World by Kurt S. Adler. This base is unique because the wires are bent against the narrow part of the wedge, rather than the wide part. |
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| 1/4 inch wedge base with tail. Used on heavy duty sets, the tail is added to keep the contacts in the socket from shorting out against each other. |
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| General Electric Merry Midget 1963 - 1978. A variation on this 2 pin base was also used on NOMA miniature sets. |
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| Combination wedge base/ reflector, NOEL standard, petal
style. The most popular reflector style, it resembled a miniature Tulip flower. |
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 Combination wedge base/
reflector, NOEL standard, petal style.An earlier style of reflector with finer petals. |
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| Combination wedge base/
reflector, NOEL standard, star style. This reflector was more resistant to breakage, but the points would snag on the wires and stepping on it in stocking feet was quite painful ! |
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| Combination wedge base/ reflector, NOEL standard, fluted
style. This style reflector was used exclusively on tree toppers. |
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The next page goes back to reflector sets.