Note: Descriptions are shown in the official language in which they were submitted.
Background of the Invention
In the testing of electronic equipment containing
a number of circuit boards including integrated circuits
mounted in DIP's it is desirable to make test connections
to the various terminals of the DIP's. In many cases it is
best to test the electrical circuits while they are operating.
Normally, circuit boards are removed from their normal
operating environment and connected to a conventional
e~tender board and connections are made to the DIP terminals
using a conventional test probe or clip. In some cases,
especially those involving high-frequency signals, the use
of an extender board may introduce electrical interference
into the circuit; thereby unacceptably altering the electrical
characteristics of the circui~ under test.
Summary of the Invention
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This invention relates to electrical connectors
for making electrical connections to electronic circuits
packaged in a DIP. More particularly, it relates to an
electrical connector for making electrical connection to
these circuits while they are in their normal operatin~
environment.
The invention is realiæed by a device comprised
of a low-profile test clip connected to a flat cable term-
inated with an electrical connector. In use, the test clip
is electrically connected to a DIP moun-ted on a circuit
board that has been removed from the equipment. The height
of the test clip is such that the circuit board may be
reinstalled in the equipment while the test clip is still
connected to the DIP, without interferring with adjacent
circuit boards. The flat cable is of such length that the
electrical connector extends beyond the physical con~ines
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of the equipment and is accessible to conventional test
probes.
The object of the present invention is to provide
a means for electrically connecting to DIP's.
Another object of the present invention is to
provide a means for electrically connecting to DIP's
mounted on circuit boards that are installed in their normal
operating environment inside the electronic equipment.
In accordance with an aspect of the invention
there is provided a low-profile device for making electrical
connection to the terminals of an electronic component for
testing the circuitry thereof, said device comprising:
a flat cable containing a plurality of insulated conductors
for carrying electrical signals; a body having spaced
electrlcal contact means mounted therein, said electrical
contact means including terminal~contact sections for
electrical connection with terminals and conductor-
connecting sections for electrical connection with electrical
conductors of said flat cable; means for gripping the
electronic component and for insulating and protecting
said terminal-contact sections of said electrical contact
means; means for retaining and spring biasing said grippin~
means to said body; a cap to cover and electrically insulate
exposed portions of said conductor-connecting sections of
said electrical contact means and to retain said contact
means in electrical connection with the electrical conductors
in said flat cable; and means for electrically connecting
between the electrical conductor~ in said flat cable and a
test instrument.
The foregoing and other objects and advantages of
the present invention will become apparent from the following
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detailed description of the preferred embodiment thereof and
from the attached drawing.
Brief Description of the Drawing
Figure 1 is a block diagram showing the low-profile
test clip adapter in a typical application;
Figure 2 is an exploded view of the low-profile
test clip adapter showing the component parts thereof; and
Figure 3 shows an assembled low-profile test clip.
Detailed Description of the Invention
Turning now to the drawings, a typical test
situation using the present invention is shown in Figure 1.
Shown are a piece of electronic equipment 2, circuit boards
4 therein, and low-profile test clip 6 electrically connected
to a DIP 7 on circuit board 4. A flat cable 8 connects-test
clip 6 to terminal block 10. Conventional test probe 12 is
connected to a connector pin in terminal block 10 and carries
signals to test instrument 14.~ With this arrangement the
electrical characteristics of circuit board 4 may be deter-
mined while it is operating within electronic equipment 2.
In order to enable circuit board 4 to be operated
within instrument 2 during tests instead of on a conventional
extender board, low--profile test clip 6 is of such height as
to allow circuit board 4 to be placed inside equipment 2
without interferring with adjacent circuit boards 4.
Low-profile test clip 6 as shown in Figure 2
contains several parts including, a body 20 r a pair of arms
22, and a cap 24. ~ody 20 is molded of a suitable plastic
material and carries a plurality of gold-plated beryllium
copper cantil.ever spring contacts 26 that provide electrical
contact between the terminals of the DIP being tested and
the conductors of flat cable 8. Figures 2 and 3 depict a
total of sixteen spring contacts 26; however, it is obvious
that any number of contacts may be carried by body 20 to
accomodate the various configurations of DIPIs.
The top portion of each spring contact 26 is fork
shaped so as to puneture and displace the insulation sur-
rounding the conductors of flat eable 8 when it is fitted
into place over spring contacts 26. Thus, electrica]
contact is made between the conductors of flat cable 8 and
spring contacts 26. The bottom portion of each spring
contact 26 springably engages and makes electrical contact
with a respective terminal of the DIP being tested. The
bottom portion of each eontact 26 is provided with in~ardly-
direeted arcuate-shaped projeetions 26a to enable the
contact to easily engage a respective terminal of the DIP.
The two arms 22 are identical and they include
C-shaped sections 21 which springably engage cylindrical
projections 23 of body 20 so t-hat arms 22 are pivotally
mounted on body 20 as shown in Figure 2. The bottom portion
of each arm 22 contains spaeed fingers 25 that are disposed
between adjaeent spring contacts to grip the body of the
DIP; thereby ensuring good electrical contact between spring
contacts 26 and the DIP terminals. Fingers 25 also protect
and prevent the spring contacts from shorting to one another.
The middle portion of each arm 22 covers and provides elec-
trieal insulation for spring contacts 26. The top portion
of arms 22 are to be engaged to pivotally move the arms away
from contacts 26 so that the eontacts ean easily engage the
DIP terminals.
Arms 22 are pivotally mounted on body 20 via
sections 21 and projections 23 so as to permit them to be
pivoted toward and away from spring contacts 26; thus,
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allowing spring contacts 26 to fit over the DIP terminals.After arms 22 are pivotally mounted onto body 20, an
O-ring 30
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: .
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is mounted within grooves 27 of arms 22 thereby maintaining arms 22 in
position on body 20 and providing spring bias to arms 22.
Body 20 contains latching arms 32 which include latching
surfaces 34. I_atching arms 32 extend through openings 36 in cap 24 when
cap 24 is positioned on body 20. Latching surfaces 34 engage a mating
surface of cap 24 as a result of the outwardly-directed spring action of arms
32 thereby latching cap 2~ in position, insulating any exposed section of
contacts 26, and retaining the electr.ical conductors of flat cable 8 in
electrical contact with spring contacts 26.
D Flat cable 8 contains a plurality of insulated conductors,
sixteen such conductors are shown in Figure 2. It is obvious, however, that
any number of conductors may be included in flat cable 8 in order to
accomodate the various configurations of DlP's. Flat cable 8 extends the
signals carried by spring contacts 26 from the DIP terminals out beyond the
physical confines of equipment 2.
Flat cable ~ is terminated with a conventional terminal block
10 surrounded by housing 35 which contains a plurality of connector pins 33.
Sixteen connector pins are shown, but it is obvious that any number may be
used in order to accomodate the corresponding number of conductors in flat
cable 8. Conventional ~est probe 12 ~rom test instrument 14 may be
connected ~o connector pins 33 to perform electrical testing on electronic
circuits within the DIP. Alternately, flat cable ~ may be terminated in a
conventional connector designed to plug directly into test instrument 14
without need of test probe 12.
While an embodiment of the present invention has been shown
and described, it will be apparent to those skilled in the art that changes and
modifications may be made without departing from the present invention in
its broad aspects. The appended claims are therefore intended to cover ali
such changes and modifications as fall within the true spirit and scope of the
invention.
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