U.S. patent number 3,623,066 [Application Number 04/783,987] was granted by the patent office on 1971-11-23 for programmable lamp illumination device.
This patent grant is currently assigned to Seismograph Service Corporation. Invention is credited to William F. Norris.
United States Patent |
3,623,066 |
Norris |
November 23, 1971 |
PROGRAMMABLE LAMP ILLUMINATION DEVICE
Abstract
A programmable computer for controlling the sequential
illumination of a plurality of light sources or lamps. Properly
programmed, this unit can produce up to 400 different lighting
patterns in a plurality of light sources. Provision is made for
illuminating different lamps sequentially and also for including a
single lamp in more than one illumination pattern. The computer and
the light sources are intended for use as a guide to assemblers of
wiring harnesses in the electronics industry. In addition to the
above-mentioned illumination control facilities, the computer
includes circuitry to aid in tracing out and separating the various
wires contained in a multiconductor cable. A set of 40 leads are
used to connect the light sources to the computer. Programming is
achieved by interposing logic elements between these 40 leads and
the light sources.
Inventors: |
Norris; William F. (Tulsa,
OK) |
Assignee: |
Seismograph Service Corporation
(Tulsa, OK)
|
Family
ID: |
25131023 |
Appl.
No.: |
04/783,987 |
Filed: |
December 16, 1968 |
Current U.S.
Class: |
345/73; 29/755;
29/720; 340/332; 345/204 |
Current CPC
Class: |
H05K
13/065 (20130101); Y10T 29/53243 (20150115); Y10T
29/53087 (20150115) |
Current International
Class: |
H05K
13/06 (20060101); G08b 005/36 () |
Field of
Search: |
;340/332,176,324,334
;29/23MW |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Caldwell; John W.
Assistant Examiner: Slobasky; Michael
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. A device for creating sequential illumination patterns in a
plurality of illumination sources comprising:
a switching unit having first and second sets of output leads;
first sequential energizing means for sequentially energizing each
lead in said first set of output leads;
second sequential energizing means for sequentially energizing each
lead in said second set of output leads each time one lead in said
first set is energized; and
one or more logic circuits each including an OR gate having two or
more inputs and further including an enable input, each logic
circuit having an output connecting to one of the illumination
sources and arranged to illuminate the illumination source when the
enable input and one of the OR gate inputs are simultaneously
energized;
circuit means connecting the inputs of the OR gate within each
logic circuit to leads in one of said sets of output leads; and
circuit means connecting the enable input of each logic circuit to
a lead in the other of said sets of output leads.
2. A device in accordance with claim 1 wherein said first and
second sets of output leads are energized with first and second
signals differing from one another in potential, wherein the
illumination sources are lamps having first and second terminals
and operable on the power supplied by said output leads, wherein
one or more of said logic circuits comprises a diode OR gate
connected to the first terminal of a lamp, wherein the inputs to
said diode OR gate are connected to leads in one of said sets and
wherein the second terminal of the lamp is connected to a lead in
the other of said sets to function as an enable input to said logic
circuits.
3. A device in accordance with claim 1 wherein said first and
second sets of output leads are energized with first and second
signals differing from one another in potential, and wherein one or
more of the logic circuits comprises:
a diode and transistor logical circuit having its inputs connected
to leads in one of said sets and having an emitter lead connected
to a lead in the other of said sets; and
a source of illumination connected to the output of said diode and
transistor logical circuit.
4. A device in accordance with claim 1 wherein at least one source
of illumination is connected to the outputs of two or more logical
circuits so as to be illuminated by any one of the logical
circuits.
5. A device for aiding in the assembly of wiring harnesses
comprising:
A first plurality of lamps each mounted adjacent a harness
component storage compartment, and a second plurality of lamps
mounted in a harness assembly area to serve as assembly guides,
said lamps each having first and second terminals;
a switching unit having first and second sets of output leads and
including means for sequentially energizing the leads in the first
set with a first potential signal and for sequentially energizing
the leads in the second set with a second potential signal each
time a lead in said first set is energized;
a plurality of diodes, two or more connecting the first terminal of
each lamp to leads in one of said sets of output leads; and
an interconnection between the second terminal of each lamp and a
lead in the other of said sets of output leads.
6. A device in accordance with claim 5 wherein some of the lamps
are interconnected so as to function together.
7. A device in accordance with claim 5 wherein additional lamps are
connected to the output leads in said sets by multiple input logic
gates.
8. A device for aiding in the placement of multiconductor cables
within a wiring harness, said device comprising:
a plurality of lamps each having first and second terminals;
a switching unit including a plurality of output leads connecting
to the lamps and also including means for sequentially energizing
the leads so as to sequentially illuminate the lamps;
a source of energizing potential for said lamps having first and
second outputs;
a probe connected to one of said energizing potential outputs;
diodes connecting the other of said energizing potential outputs to
one or more of the switching unit output leads connecting to the
first terminals of said lamps; and
interconnections between a number of the cables comprising the
multiconductor cables and the second terminals of some of said
lamps;
whereby the placement of a selected cable can be determined by
touching the probe to the conductor and observing the illumination
pattern.
9. A switching unit for sequentially energizing lines in a first
group of lines, and for sequentially energizing lines in a second
group of lines whenever a line in the first group is energized,
said unit comprising:
first and second wiper arms connected to an energization source and
respectively arranged to sequentially make contact with the lines
in the first and second groups;
first and second stepping relays respectively mechanically coupled
to said first and second wiper arms, said relays each arranged to
advance upon receipt of a pulse;
a pacer source of pulses for advancing said second stepping
relay;
a pulse former source of pulses energized by said second stepping
relay for advancing said first stepping relay one position for each
complete rotation of said second stepping relay;
an additional wiper arm and set of wiper arm contacts for each
stepping relay; and
a shorting switch for shorting the additional wiper arm contacts of
each stepping relay;
whereby the stepping switches can be adjusted to slew past any
specified number of positions.
10. A switching unit for sequentially energizing lines in a first
group of lines, and for sequentially energizing lines in a second
group of lines whenever a line in the first group is energized,
said unit comprising:
first and second wiper arms connected to an energization source and
respectively arranged to sequentially make contact with the lines
in the first and second groups;
first and second stepping relays respectively mechanically coupled
to said first and second wiper arms, said relays each arranged to
advance upon receipt of a pulse;
a pacer source of pulses for advancing said second stepping
relay;
a pulse former source of pulses energized by said second stepping
relay for advancing said first stepping relay one position for each
complete rotation of said second stepping relay; and
a slew switch connected to the pacer for accelerating the pacer and
for routing the pacer pulses to either stepping relay.
11. A switching unit for sequentially energizing lines in a first
group of lines, and for sequentially energizing lines in a second
group of lines whenever a line in the first group is energized,
said unit comprising:
first and second wiper arms connected to an energization source and
respectively arranged to sequentially make contact with the lines
in the first and second groups;
first and second stepping relays respectively mechanically coupled
to said first and second wiper arms, said relays each arranged to
advance upon receipt of a pulse;
a pacer source of pulses for advancing said second stepping
relay;
a pulse former source of pulses energized by said second stepping
relay for advancing said first stepping relay one position for each
complete rotation of said second stepping relay; and
an external advance switch included within the pacer which advance
switch, when depressed, causes the pacer to generate a pulse
prematurely.
Description
The present invention relates to lamp illumination controllers, and
more particularly to controllers suitable for guiding an assembler
of wire harnesses in the layout of wires comprising the
harness.
In the past, it has been customary to construct the complicated
wiring harnesses needed in the electronics industry by first
placing a blueprint of the harness on a table, and then assembling
the wire harness directly over the blueprint. Each time the
assembler places another wire into the harness, he has to consult
the wiring list or the blueprint to determine what length of wire
is required, obtain a wire, and then place it into the harness. The
procedure is slow, since the assembler must refer to a diagram or a
print before placing each wire. It is easy for the assembler to
miss a wire, or misplace a wire, so errors in wiring occur
frequently.
A device for guiding an assembler of harnesses in placing his wires
is disclosed in an application for letters patent filed by Gerald
D. Holmburg, Ser. No. 769,900 filed Oct. 23, 1968 and assigned to
the same assignee as the present application. The Holmburg
application discloses an arrangement whereby sets of three lamps
are sequentially illuminated to guide the harness assembler. One
lamp within each set is placed next to the container where the
proper length wire is stored, and the remaining lamps in the set
are placed at the locations where the wire is to begin and where it
is to end in the harness assembly. A lamp illumination control then
sequentially illuminates the sets of three lamps, one set at a
time. The lamp illumination control is caused to advance from one
set to the next by a footswitch which the assembler depresses after
each wire is placed into the harness assembly. The assembler
removes a wire from the illuminated container, places it in the
harness so that it extends between the illuminated lights on the
harness wiring board, and then depresses the footswitch to
illuminate the next set of lights. In this manner, an entire wiring
harness can be assembled rapidly and with little chance for
error.
The Holmburg apparatus utilizes a lamp illumination device which is
essentially a 50-position stepping switch that can sequentially
illuminate up to 50 sets of lamps. The Holmburg lamp illumination
device is unable to illuminate a single lamp more than once during
a given 50-step sequence, and cannot provide more than 50 different
patterns of illumination. More combinations can be added to the
Holmburg device only by adding additional stepping relays to the
programmer or by increasing the number of positions on each
stepping relay. An additional drawback of the Holmburg apparatus is
that it requires a separate output terminal for each set of lamps.
Thus, if the Holmburg device were redesigned to give several
hundred combinations, it would have to be provided with several
hundred separate output terminals. Such a large array of output
terminals would make it difficult to reprogram the device for a
different harness layout, and also would add significantly to the
expense of the apparatus.
It is an object, therefore, of the present invention to provide a
programmable device for controlling lamp illumination that can
provide several hundred different illumination patterns, but that
never requires more than 2 N output terminals to produce N.sup.2
different illumination patterns. Thus, 40-output terminals suffice
to provide 400 different illumination patterns.
A further object of the present invention is to provide a
programmable lamp illumination device that can illuminate any
individual lamp during any of a number of lighting sequences, and
that does not have to have an entirely separate set of lamps for
each possible lighting sequence.
Another object of the present invention is to provide a device
which can determine the placement of the individual conductors
within a multiwire cable without requiring an assembler to refer to
the color coding of the wires within the cable.
In accordance with these and many other objects, the present
invention comprises a programmable computer for sequential
illumination of a plurality of light sources or lamps. The device
includes basically two stepping relays, one associated with a
plurality of positive output leads, and another associated with a
plurality of negative output leads. One of the output stepping
relays advances either when a footswitch is depressed, or else
sequentially after a fixed length of time. The second stepping
relay advances one position each time the first stepping relay
advances through its entire complement of output leads. At any
given time, only one positive and only one negative output lead is
energized, and only lamps interconnecting the energized leads are
illuminated.
Programming comprises connecting lamps to the various positive and
negative output leads with logic gates and elements. As a simple
example, a lamp in series with a diode can be connected between a
given positive and a given negative lead. This lamp is illuminated
only when both of the chosen leads are energized. A lamp connected
in this manner is illuminated only once during an entire sequence
of illumination patterns. Much more complicated arrangements of
lamp illumination can be provided. For example, one end of a lamp
can be connected to a positive lead, and the other end of the same
lamp can be connected by diodes to two, three or more negative
leads. Such a lamp is illuminated when the positive lead and any
one of the negative leads are supplied with power by the stepping
switches. In this manner, a single lamp can be included in two,
three, and four or more different illumination patterns. Much more
complicated arrangements using logic elements such as transistor
NOR gates and NAND gates will be discussed in detail in the
specification to follow.
In addition to the above facilities, the present invention also
provides means whereby complicated multiconductor cables can be
laid into a wiring harness. The cables are plugged into a plug that
is wired together with lamps placed in the locations to which the
cable wires are to be run. A probe from the computer is then
sequentially touched against each of the leads coming from the
multiconductor cable. As each lead is touched by the probe, one or
more lamps on the assembly table are illuminated, thus indicating
where that particular wire is to be placed. In this manner, a
multiconductor cable can be quickly placed into a wiring
harness.
The present invention is equipped with switches permitting the
number of available positive and negative leads to be reduced from
a maximum number in the case of harnesses not requiring 400
lighting combinations. This reduction in number of available leads
is accomplished by two switches, one associated with positive
leads, and one associated with the negative leads. Each of these
switches can be set to cause the associated stepping relay to slew
past any desired number of leads. In this way, the number of
available output leads can be varied over a wide range to suit
differing applications.
Additional objects and advantages will become apparent in
considering the following detailed description in conjunction with
the drawings in which:
FIG. 1 is a perspective view of a wiring harness assembly table of
a type suitable for use with the present invention;
FIG. 2 is an elevational view of a sequential lamp illumination
computer switching unit 500 designed in accordance with the present
invention;
FIG. 3 is a block diagram of the switching unit 500;
FIGS. 4A and 4B, when placed side by side, form a detailed
schematic diagram of the sequential lamp illumination switching
unit 500;
FIG. 5 shows one possible way in which a lamp illumination computer
designed in accordance with the present invention can be programmed
to illuminate a plurality of lamps;
FIG. 6 shows how a lamp illumination computer designed in
accordance with the present invention can be programmed to guide
the placement of leads in a multiconductor cable.
Referring now to the drawings, FIG. 1 shows a typical wiring
harness assembly area of the type disclosed in the Holmburg
application. Differing lengths and types of wires are stored in a
plurality of tubular wire storage compartments 10. Each compartment
is equipped with a source of illumination or lamp 12. The sources
of illumination 12 are sequentially illuminated and serve as an
indication of which compartment wire is to be withdrawn from at any
given time. A table 14 is provided upon which a wiring harness can
be assembled. Individual lamps are mounted upon the table 14 and
are oriented to serve as guides to the assembler of the harness.
Pins, springs, and other devices useful for holding the elements of
a wiring harness in place are also positioned upon the table 14.
The details of the lamp positioning and harness wire location
equipment are disclosed in the Holmburg application, and will not
be repeated here. For the purposes of the present invention, any
suitable arrangement for positioning a plurality of lights and for
holding the elements of a wiring harness in place can be used.
There is one important difference between the present apparatus and
the apparatus described in the concurrently filed Holmburg
application. In the present apparatus, the lamps must be
insulatively mounted, and two individual power leads usually must
be provided for each lamp. In the Holmburg device a metallic
chassis is used as a common ground for one terminal of each lamp
and also serves as a lamp-mounting board. If the Holmburg device is
to be used in conjunction with the present invention, it must be
modified to insulate the lamps from one another. For example, the
metallic chassis can be replaced by a nonmetallic insulative
chassis, and an additional lead can be added to each lamp.
The computer switching unit that sequentially energizes the lamps
is indicated by 500 in FIG. 1, and the front panel of this unit is
shown in FIG. 2. The controls shown in FIG. 2 will be explained
below.
Referring now to FIGS. 3 and 5, there is shown a programmable lamp
illumination computer designed in accordance with the present
invention. FIG. 3 is a block diagram of the computer switching unit
500. The output of the unit 500 (FIG. 3) comprises 40 output leads
M 1 through M 20 and N 0 through N 19. The switching circuitry of
FIG. 3 first energizes the lead N 0 and sequentially energizes each
of the leads M 1 through M 20. The lead N 1 is then energized and
the leads M 1 through M 20 are again sequentially energized. This
process continues until all of the leads have been sequentially
energized.
FIG. 5 shows the programming logic used to interconnect the
40-output leads from the computer switching unit 500 (FIG. 3) and
the lamps or sources of illumination. In FIG. 5, the M-output leads
are represented by horizontal lines, and the N-output leads are
represented by vertical lines. At each location where an M-line
crosses an N-line, one or more lamps wired in series with diodes
are connected between the N-line and the M-line. These lamps or
groupings of lamps have been given numbers 101 through 124 in FIG.
5. The lamp 101 is energized when the lines M 1 and N 0 are
energized. The lamp 102 is energized when the lines M 2 and N 0 are
energized. In a similar manner, all of the other lamps are also
energized when their corresponding pairs of lines are energized.
Since the entire sequence of M-lines is energized each time a
single N is energized, the lamps are illuminated in the same order
as they are numbered, that is, lamp 101 is illuminated first, then
lamp 102, then lamp 103, and so forth to lamp 124. These lamps can
be thought of as connected to their corresponding two lines by a
form of AND circuit which requires both of the corresponding lines
to be energized before a lamp is energized. This is not precisely
true, since the M-lines are energized by a positive potential
whereas the N-lines are energized by a negative potential. The lamp
diode circuits thus comprise a very simple form of logic circuit
for indicating when a particular pair of lines are both
energized.
More complicated logic circuits can also be used to illuminate a
particular lamp at more than one time. For example, the lamp 152 is
illuminated whenever the lamps 106, 107, 108, or 112 are
illuminated. A transistor 150 illuminates the lamp 152 whenever one
of the lamps 106 to 108 is illuminated. The transistor 150 conducts
whenever its emitter, which connects to the line N 1, is negative,
and simultaneously its base is positive. The base of the transistor
150 is connected through a resistor 163 and diodes 160 to 162 to
the three lines M 2 to M 4. Thus, whenever the line N 1 is negative
and one of the three lines M 2 to M 4 are positive, the transistor
150 conducts and illuminates the lamp 152. The elements 150, 160,
161, 162, and 163 comprise a diode-transistor NOR gate that is
activated when the line N 1 is negative. The lamp 152 is also
illuminated when the transistor 151 conducts. The transistor 151
conducts whenever both the line N 2 and the line M 4 are energized,
and thus illuminates the lamp 152 whenever the lamp 112 is
illuminated. The transistor 151 and the associated circuitry
comprise an inverting or NOT gate, and the connection between the
collectors of the transistors 151 and 152 is equivalent to an OR
logic gate.
Another lamp 154 is illuminated in a manner similar to the way in
which the lamp 152 is illuminated. A transistor 156 illuminates the
lamp 154 whenever the line M 3 supplies a positive potential to the
emitter of the transistor 156, and one of the lines N 3 through N 5
supplies a negative potential through one of the diodes 170 through
172 and a resistor 173 to the base of the transistor 156. A second
transistor 155 illuminates the lamp 154 whenever the line M 4 is
positive and the line N 5 is negative. The elements 156 and 170-173
comprise a NAND gate activated by the line M 3. The transistor 155
and the associated circuitry comprises an inverting or NOT gate
enabled by the line M 4. The interconnection between the collectors
of the transistors 155 and 156 is equivalent to an OR logic gate,
so either transistor can illuminate the lamp 154.
A lamp 153 is arranged to be illuminated whenever the line M 1 is
positive and one of the four lines N 2 through N 5 are negative.
The diodes connecting the lamp 153 to the four lines N 2-N 5
comprise an AND gate or inverted signal OR gate that passes a
negative signal to the lamp 153 whenever any of the lines are
negative. Another lamp 180 is energized whenever the line N 0 is
negative and one of the four lines M 1 to M 4 is positive. This
lamp is connected in a manner similar to the way the lamp 153 is
connected, except that the diodes are reversed to compensate for
the change in the polarity of the energized lines. The set of
diodes associated with the lamp 180 comprise an OR logic gate.
The lamps shown in FIG. 5 are arranged so that when any one M-line
receives a positive potential and any one N-line receives a
negative potential, two and only two lamps are energized. For
example, when the lines M 1 and N 0 are energized, lamps 101 and
180 are illuminated. When the lines N 1 and M 1 are energized, the
two lamps 105 are illuminated. One of these lamps in assumed to be
located adjacent the wire storage receptacle 10 (FIG. 1) where a
wire of the proper length is stored. The other lamp is located in
the wiring harness assembly area and serves as a guide to the
assembler as to the placement of the wire. It is understood that
more than one lamp may be required to indicate where a wire is to
be placed, and that extra lamps may be connected in parallel or in
series with the lamps shown in FIG. 5 as may be convenient.
Referring now to FIG. 3, the computer switching unit 500 for
sequentially energizing the M- and N-lines in FIG. 5 is shown in
block diagram form. This circuit includes two stepping relay
switches, SM and SN. The switches themselves are not shown in FIG.
3, but all of the wiper arms and contacts associated with the
switches are shown in FIG. 3. The two stepping relay switches SM
and SN each include four wiper arms labeled respectively A, B, C,
and D. The A- and B-wiper arms each have 26 sequential contacts--a
home (H) contact, and contacts labeled 1-25. The A-wiper arms (SMA,
SNA) are used to control the slewing of the two stepping relay
switches, as will be explained. The B-wiper arms (SMB, SNB) are
respectively used to energize the M- and N-series of output leads.
The M-series of output leads are successively connected to a
positive potential by the wiper arm SMB of the stepping relay
switch SM, and the N-series of output leads are successively
grounded by the wiper arm SNB of the stepping relay switch SN. The
C-wiper arms, (SMC, SNC) of each stepping relay switch are in the
position shown in FIG. 3 only when the associated stepping relay
switches are in the home position. At all other times, the C-wiper
arm is in the opposite state from that shown in FIG. 3. The D-wiper
arms (SMD, SND) are in the position shown whenever the associated
stepping relay switch is at rest. When a stepping relay switch is
energized, the D-wiper arm shifts momentarily into the other
position. A relay coil is associated with each of the stepping
relay switches. A coil KM is associated with the switch SM, and a
coil KN is associated with the switch SN.
When the switch 502 is closed, a power supply 504 is energized to
maintain a potential between a ground node 506 and a B+ node 508.
When a start pushbutton 510 is depressed by the cable assembler,
the positive potential from the B+ node 508 is applied to the wiper
arm SNA. Positive current flows through this wiper arm, the contact
H, the wiper arm SND, and energizes the relay coil KN and causes
the stepping switch relay SN to advance 1 position. The wiper arm
SNA is now touching its associated first contact, and the wiper arm
SNB is now grounding its associated first contact. Since the first
contact associated with the wiper arm SNB connects to the N 0
output line, that line is now energized with a ground level
negative potential. The switch SNC now shifts to the opposite
position from its position as shown in FIG. 3 and connects the B+
node 508 to a node 512. Positive current now flows from the node
512 to the wiper arm SMA, and through a diode 514 to the wiper arm
SNA. The two wiper arms SMA and SNA remain connected to the B+ node
508 until the computer switching unit 500 has operated through an
entire illumination cycle. The node 512 is also connected to the
wiper arm SMB by a circuit breaker 516. The wiper arm SMB remains
continuously supplied with a positive potential until the computer
switching unit 500 has operated through an entire illumination
cycle, and the wiper arm SNB remains continuously grounded. The
wiper arm SMB now sequentially energizes the leads M 1 to M 20, and
the wiper arm SNB sequentially energizes the leads N 0 through N 19
as explained above.
The positive potential on the wiper arm SMA causes a current to
flow through the contact H, a diode 520, an AND-gate 522, the wiper
arm SMD, and into the relay coil KM. This current energizes the
stepping switch relay SM and causes it to advance the wiper arms
SMA and SMB to their respective first contact positions, thus
energizing the line M 1. Simultaneously, the wiper arm SMC changes
its state and supplies a positive potential to a pacer 524. The
pacer 524 is a pulse generator that generates a pulse every 5 to 90
seconds, depending upon how it is set up. Connected to the pacer
524 is an external advance switch 526, usually a foot switch that
can be depressed by the cable assembler whenever it is desired to
have the pacer generate a pulse prematurely. Periodically the pacer
524 generates a pulse which passes through a wiper arm 528B of a
slew switch 528 and activates a one-shot 530. The one-shot 530
applies a surge of current through the wiper arm SMD to the
stepping switch relay coil KM. This surge of stepping switch relay
SM to advance one position. Thus, the wiper arm SMB is periodically
advanced so as to energize each of the lines M 1 through M 20. In
this manner, all of the lines M 1 through M 20 are sequentially
energized.
When the wiper arms SMA and SMB reach their respective contacts 21,
a current path is established from the positive potential node 512
through the wiper arm SMA, the contacts 21-24, the diode 520, the
AND-gate 522, and the wiper arm SMD to the relay coil KM. This
current causes the relay SM to slew until the wiper arms SMA and
SMB reach their respective contacts 25. A current path is now
established from the positive potential node 512, through the wiper
arm SMA and the contact 25 to a pulse former 532. This pulse former
supplies a single pulse to a one-shot 534 and causes the one-shot
534 to supply a current pulse through the wiper arm SND to the
stepping switch relay coil KN. This current pulse advances the
stepping switch relay SN so that the wiper arms SNA and SNB advance
to their respective second contacts. As noted above, the wiper arm
SND momentarily toggles to its alternate position while the
stepping switch relay SN advances. When this happens, a low-level
residual current flows from the one shot 534 through the wiper arm
SND and the slew switch wiper arms 528C and 528B and into the
one-shot 530. This residual current fires the one-shot 530 and
causes a current pulse to be applied to the relay coil KM, thus
advancing the stepping switch relay SM to the home position. As
explained above, the stepping switch relay SM immediately advances
the wiper arms SMA and SMB to their respective first contact
position thus energizing the line M 1 once again. At this point in
time the lines M 1 and N 1 are both energized, and they illuminate
the lamps 105 shown in FIG. 5. The pacer 524 continues to generate
pulses, and these pulses cause the stepping switch relay SM to
advance the wiper arm SMB so that is once again sequentially
energizes all of the lines M 1 through M 20. This causes the lamps
105 to 108 and all lamps similarly connected to the line N 1 to be
sequentially energized.
In a like manner, each of the lines N 0 to N 19 is sequentially
energized with a ground level signal by the wiper arm SNB. Each
time one of these lines is energized, the entire sequence of lines
M 1 through M 20 are sequentially energized with a positive
potential by the wiper arm SMB. This causes all of the lamps shown
in FIG. 5 to be illuminated in the manner explained above. The
total number of possible illumination patterns that can be
generated by this arrangement is equal to the number of M-lines
multiplied by the number of N-lines, in this case 400. The time
duration of each illumination pattern is determined by the spacing
between the pulses generated by the pacer 524. As mentioned above,
the assembler can shorten a time duration by depressing the
external advance switch 526 and forcing the pacer 524 to generate a
pulse prematurely.
A slew switch 528 allows the assembler to advance either of the
stepping switch relays SM or SN manually. When the slew switch 528
is placed in the M-position, the stepping switch relay SM advances
sequentially. When the slew switch 528 is placed in the N-position,
the stepping switch relay SN advances sequentially. When the slew
switch 528 is placed in either the N- or a M-position, the wiper
arm 528A greatly accelerates the rate at which the pacer 524
generates pulses. If the switch 528 is in the M-position, these
pulses are applied to the one-shot shot 530 by the wiper arm 528 B,
and cause current pulses to be applied to the relay coil KM
associated with the stepping switch relay SM. If the switch 528 is
in the N- position, the pulses from the pacer 524 pass through the
wiper arm 528B to the one-shot 534 and result in current pulses
being applied to the relay coil KN associated with the stepping
switch relay SN. When the stepping switch relay SN is being slewed,
the wiper arm 528C opens and prevents current from the one-shot 534
from passing through the wiper arm SND and back to the wiper arm
528B.
After the entire sequence of illumination patterns has been
completed, the wiper arms SMA and SMB are adjacent their respective
contacts 21, and the wiper arms SNA and SNB are adjacent their
respective contacts 20. The stepping switch relay SM now slews
until the wiper arms SMA and SMB are adjacent their respective
contacts 25, in the same way that it slews past the home position
H. A positive potential current now flows from the node 512 through
the wiper arm SMA and the associated contact 25 into the pulse
former 532, and causes the stepping switch relay SN to advance the
wiper arms SNA and SNB to their respective contacts 21. A positive
potential path is now established from the positive potential node
512 through the diode 514, the wiper arm SNA, contacts 21 through
25, a diode 536, and the wiper arm SND to the relay coil KN.
Current flows over this current path and causes the stepping switch
relay SN to slew past the contacts 21 through 25 and back to the
home position. While this is happening, the wiper arm SND sends
current from the one-shot 534, through the wiper arms 528C and 528B
of the slew switch, and into the one-shot 530, thus causing the
stepping switch relay SM to advance the wiper arms SMA and SMB back
to their respective home positions. When the wiper arms SMA and SMB
reach the home position, the wiper arm SMC returns to the position
shown in FIG. 3 and cuts off power to the one-shot 530. This
prevents the one-shot 530 from supplying any more current pulses to
the relay coil KM. The only remaining path whereby current could
flow to the relay coil KM is through the AND-gate 522, but this
path is broken by a disabling signal supplied to the AND-gate 522
by an invertor 538. This invertor 538 is energized by the potential
appearing upon the contacts 21 through 25 associated with the wiper
arm SNA. The stepping switch relay SM is therefore locked in the
home position until the stepping switch relay SN slews past the
contacts 21-25 and also returns to the home position. When the
stepping switch relay SN reaches its home position, the wiper arm
SNC returns to the position shown in FIG. 3 and cuts off the supply
of positive potential to the node 512. This disables the computer
switching unit 500 and terminates the sequential lamp illumination
process.
As mentioned above, it is possible to adjust the stepping switch
relays SM and SN so that they automatically slew past any number of
contacts. This is done with the assistance of two shorting
switches, not shown in FIG. 3. A first shorting switch is connected
to a terminal Z (connected to terminal 21, wiper arm SMA), and is
arranged to connect the terminal Z to any desired number of the
terminals labeled X (connected to terminals 2-20, wiper arm SMA). A
second shorting switch is connected to a terminal W (connected to
contact 21, wiper arm SNA), and is arranged to connect the terminal
W to any desired number of the terminals labeled Y (connecting to
contacts 2-20, wiper arm SNA). Adjustment of these two shorting
switches allows any desired number of additional contacts to be
added to the two parallelly connected strings of slewing contacts
labeled 21-24. Thus, the two shorting switches allow the two
stepping switch relays to be set up to slew past any desired number
of contacts.
In addition to the outputs M 1 to M 20 and N 0 to N 19, the
computer switching unit 500 has four other outputs. Two of these
additional outputs are merely sources of operating current for
external devices, such as the logic gates shown in FIG. 5. A B+
output 540 connects to the B+ node 508, and a ground output (not
shown) connects to the ground node 506. Two additional outputs are
provided to facilitate the process of sorting and arranging the
wires in a multiconductor cable. The first of these outputs is
called the C+ output 542, and the second is called the G-output
544. When the stepping switch relay N is in the home position, the
wiper arms SNC and SNB respectively energize C+ output 542 and the
G-output 544 with positive and negative level signals. The outputs
542 and 544 are thus energized when the computer switching unit 500
is in the standby condition before the beginning of or after the
termination of an illumination sequence, the usual times when a
multiconductor cable is added to a wiring harness.
Referring now to FIG. 6 there is shown an example of how the lamp
illumination computer can be programmed so as to assist an
assembler in positioning the leads from a typical multiconductor
cable. The leads from such a cable cannot be individually placed in
the compartments 10 (FIG. 1) so special arrangements are required.
The leads comprising the cable are numbered 602-608, and are
assumed to be terminated by a plug or connector 610. A plug or
connector of the opposite sex 612 is positioned permanently in the
harness assembly area at a convenient location where the plug 610
can be connected to it. The harness assembler grasps a probe 614
and touches it to the exposed end of one of the conductors 602.
This causes one or more lights to be illuminated in the assembly
area. The lights indicate where this particular conductor is to be
positioned. The assembler places this wire in the position
indicated by the lamps, and then touches the probe 614 to the
exposed end of the next conductor 604. This process is repeated
until all of the conductors are properly positioned in the harness.
The probe 614 is connected to the C+ output of the computer
switching unit 500, and is therefore energized only during standby
periods either before the commencement of a lighting sequence or
after the end of a lighting sequence. These are the times when
multiconductor cables are most usually incorporated into a wiring
harness. During this same period, the G-output 544 also energizes
and supplies a negative potential to one side of a pair of lamps
620 and 622. These are the lamps which are respectively illuminated
when the probe 614 is touched to the exposed ends of conductors 606
and 608. The G-output terminal 544 is also connected by two diodes
624 and 626 to the output lines N 1 and N 2. This allows lamps
connected to these two output lines to be used in guiding the
placement of connectors from a multiconductor cable. In particular,
a lamp 210 is used to indicate the placement of the conductor 602
and a lamp 212 is used to indicate the placement of the conductor
604. Diodes 211 and 273 prevent the lamps 204 and 205 from
receiving power when the lamp 210 or the lamp 212 is illuminated.
In this manner, lamps included in the various normal lighting
sequences can also be used to guide the assembler in the placement
of the conductors in a multiconductor cable.
The switches SNB, SNC and SMB (FIG. 3) are duplicated in FIG. 6 and
are shown in the positions which they occupy when the leads of a
multiconductor cable are being placed into a harness. The wiper arm
SNC supplies B+ potential to the C+ output 542 and the wiper arm
SNB supplies a ground level potential to the G-output, 544. When
the assembler is finished positioning the leads of the
multiconductor cables, the assembler depresses the pushbutton 510
(FIg. 3) and initiates the lamp illumination sequence. The wiper
arm SNC then changes its position and supplies positive current to
the wiper arm SMB. The wiper arms SMB and SNB also change their
positions and begin the process of sequentially energizing the
lines M 1 through M 20 and N 0 through N 19. The lamps 201 through
206 and all other lamps which might be included in the programming
sequence are then sequentially illuminated in the same manner as
were the lamps shown in FIG. 5.
FIGS. 4A and 4B, when placed side by side, form a detailed
schematic diagram of the computer switching unit 500. Since this
diagram has already been explained for the most part in connection
with FIG. 3, it is only necessary now to describe those features of
the diagram which are represented as blocks in FIG. 3.
The power supply 504 is conventional in every respect. It includes
two parallelly connected transformers 550 having their respective
input windings connected in parallel for 110 volts or in series for
220 volts. The output voltage is stabilized by a filter capacitor
552, and a leakage resistor 554 is provided to discharge the
capacitor 552 when the unit 500 is turned off.
The pacer 524 comprises basically a unijunction transistor
oscillator. When a positive potential is supplied to a node 558 by
the wiper arm SMC, this unijunction transistor oscillator generates
periodic pulses which appear at the wiper arm 528B. A capacitor
560, a resistor 562, and a variable resistor 564 determine the time
delay between output pulses. The variable resistor 564 is adjusted
to give the desired rate of operation. When the capacitor 560 is
charged up to a level higher than the threshold voltage of a
unijunction transistor 556, the capacitor 560 is discharged through
the diode 564, the unijunction transistor 556, and resistor 566,
thus producing an output voltage pulse at the wiper arm 528B. When
the slew switch 528 is in either the M- or the N-position, a
resistor 568 is connected in parallel with the resistors 562 and
564 in the circuit. The resistor 568 has a low ohmic value and
therefore greatly accelerates the pulse repetition rate. The
external advance switch 526 causes a pulse to appear at the wiper
arm 528B prematurely by connecting a capacitor 572 to the emitter
of the unijunction transistor 556. The capacitor 572 is normally
charged to a positive potential by current flowing through a
resistor 570. When the external advance switch 526 is closed, the
capacitor 572 discharges through the unijunction transistor 556.
Only one pulse appears at the wiper arm 528B, because the resistor
570 has a low ohmic value to maintain the unijunction transistor
556 in a conducting state so long as the external advance switch is
held closed, but does not have so low an ohmic value as to produce
a substantial voltage across the resistor 566.
The pacer 524 includes a two position switch 565 which can decouple
the resistor 564 from the timing capacitor 560 and disable the
pacer circuit. This switch is thrown to the manual or MAN position
whenever it is desired to have the light pattern changed only when
the external advance switch 526 is depressed. Normally this switch
is in the automatic or AUTO position, and the pacer 524 operates as
explained above.
The one-shots 530 and 534 are identical, so a description of the
one-shot 530 will suffice as a description of the one-shot 534.
Basically, the one-shot 530 comprises silicon-controlled rectifier
574. This silicon-controlled rectifier 574 connects the wiper arm
SMD to the positive potential point 558. When a positive pulse
appears on the wiper arm 528B, this positive pulse is fed by a
resistor 578 to the trigger input of silicon-controlled rectifier
574, and causes the rectifier 574 to conduct. A resistor 576
prevents low-level voltage pulses from firing the
silicon-controlled rectifier 574. The silicon-controlled rectifier
574 remains in a conducting state until the wiper arm SMD breaks
the circuit and allows the rectifier to turn off.
Elements 580, 582, and 584 prevent the silicon-controlled rectifier
574 from firing when the wiper arm SMC applies power to the
one-shot circuit 530. Elements 586 and 588 suppress the transient
which otherwise would occur between the wiper arm SMD and its
respective contact. Diode 590 suppresses arcing of the stepping
switch relay coil KM. The corresponding elements associated with
the one-shot circuit 534 perform equivalent functions.
The inverter 538 includes a transistor 701 and two resistors 700
and 702. The input resistor 700 connects to the base of the
transistor 701, and the resistor 702 connects the collector of the
transistor 701 to the cathode of the diode 520. When no positive
voltage is applied to the resistor 700, the transistor 701 does not
conduct and the collector of the transistor 701 floats to the
potential of the diode 520. When a positive signal is applied to
the resistor 700, the transistor 701 conducts and pulls its
collector to ground potential. The AND-gate 522 comprises the
transistor 703. The output of the AND gate is the emitter of this
transistor. The inputs are the collector and the base elements of
this transistor. The emitter output element is positive only when
both the base and the collector elements of this transistor are
positive. This occurs only when the cathode of the diode 520 is
positive, and simultaneously the transistor 701 is rendered
nonconductive by a ground level signal applied to the resistor
700.
The pulse former 532 is designed around a unijunction transistor
591. This circuit generates a single high-current pulse in response
to a rising potential applied to a resistor 596. Normally, the
unijunction transistor 591 is nonconductive. A capacitor 594 is
charged by resistors 597 and 598 to a potential slightly below the
firing or threshold potential of the unijunction transistor 591.
When a positive potential is applied to the resistor 596, the
current flowing through the resistor 596 renders the unijunction
transistor 591 conductive between the emitter electrode and the
lower base electrode. A conducting path is thus established from
the nongrounded end of the capacitor 594, through the diode 595,
the unijunction transistor 591, and a resistor 593 back to the
grounded end of the capacitor 594. The capacitor 594 quickly
discharges over this path and produces a voltage pulse which
appears across the resistor 593. This voltage pulse is the output
of the pulse former 532. After a single pulse has been delivered,
current through the resistor 596 keeps the unijunction transistor
591 in a conducting state. So long as the unijunction transistor
591 continues to conduct, a conduction path is formed from the
positive node 512 through the resistor 598, the diode 595, the
unijunction transistor 591, and the resistor 593 to ground. Since
the last three portions of this conducting path are of low ohmic
value, these last three elements maintain the capacitor 594 in a
discharged state. Only a small potential appears across the
resistor 593. This small potential is not large enough to trigger
the one-shot 534 a second time. Thus, the pulse former 532
generates a single pulse in response to a rising level input
signal.
The circuit breaker 516 is not shown in detail in FIG. 4B. The
purpose of this circuit breaker is to prevent dangerous shocks or
excessive heating during the experimental period when the computer
is being programmed. Preferably it should be a mechanical,
fast-acting circuit breaker of a type that can be easily reset
after it has been triggered by an overload. Such devices are
readily obtainable.
Referring once again to FIG. 2, the front panel of the computer
switching unit is shown in detail. The various controls are
assigned index numbers corresponding to the numbers assigned to
their schematic representations in FIGS. 3 and 4. The element 714
is a pilot lamp that is illuminated whenever a switch 502 is in the
ON position. The switches 710 and 712 are the shorting switches
used to control the slewing of the stepping switch relays SM and SN
as explained above. The AUTO-MAN pacer switch 565 (shown in FIG.
4A) can be included as an electrical switch associated with the
variable resistor 564. Alternatively, the switch 565 can be placed
on the back panel of the computer switching unit 500. A jack for
the external advance switch 526 is also conveniently located on the
back of the switching control unit 500.
The following are the values of the components used in the computer
switching circuit 500:
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Element No. Name of Element Value
__________________________________________________________________________
514 diode 1N2070 520 diode 1N2070 536 diode 1N2070 552 capacitor
2,500 micro- farads 554 resistor 10.000 ohms 556 unijunction
transistor 2N1671B 559 resistor 470 ohms 560 capacitor 150 micro-
farads 562 resistor 33,000 ohms 564 variable resistor 500,000 ohms
566 resistor 15 ohms 567 resistor 220 ohms 568 resistor 4,700 ohms
570 resistor 470 ohms 572 capacitor 150 micro- farads 574 silicon
con- trolled rectifier C6F 576 resistor 10,000 ohms 578 resistor
22,000 ohms 580 resistor 470 ohms 582 capacitor 1 microfarad 584
diode 1N483 586 resistor 50 ohms 588 capacitor 1 microfarad 590
diode 1N2070 591 unijunction transistor 2N1671B 592 resistor 220
ohms 593 resistor 100 ohms 594 capacitor 1 microfarad 595 diode
1N483 596 resistor 3,300 ohms 597 resistor 100,000 ohms 598
resistor 150,000 ohms 700 resistor 68,000 ohms 701 transistor
2N3566 702 resistor 470 ohms 703 transistor 2N1613 714 pilot lamp
NE51H (for 110v.) NE58 (for 220v.)
__________________________________________________________________________
In the programming circuitry shown in FIGS. 5 and 6, any switching
transistors and any diodes or any equivalent logic circuits having
breakdown ratings in excess of the voltage generated by the power
supply 504 can be satisfactorily used. The lamps used in
conjunction with this invention should have voltage requirements
which match the output voltage of the power supply 504. Any
suitable power supply 504 can be used in conjunction with this
invention. In the preferred embodiment, a 20 volt power supply is
used. The present invention can be modified to drive 6 volts lamps
either by choosing a lower voltage power supply 504 and modifying
the logic and relay circuits to operate with the lower voltage
power supply, or else by replacing the circuit breaker element 516
with a separate low voltage power supply connected between the
wiper arm SMB and the ground potential node 506.
The discrete component logic circuits shown in the figures. can be
replaced, if desired, by integrated circuit logic elements, which
may be powered by a separate power supply. In addition to the logic
programming shown, other arrangements may be used. For example, a
flip-flop can be arranged to illuminate a lamp during one lighting
sequence and to extinguish the lamp during a later lighting
sequence. Such a flip-flop could be set by the transistor 151 (FIG.
5) and cleared by the transistor 155, for example. A lamp connected
to the output of such a flip-flop would remain illuminated from the
time when the lines N 2-M 4 are energized until the time when the
lines N 5-M 4 are energized. Any desired sequential lamp
illumination scheme can thus be obtained by proper logic
programming.
* * * * *