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According to another feature of the invention, means CONDITION-INITIATED LOAD CONTROL are provided to sequence the circuit controller so that
CIRCUIT it normally de-energizes the load.
According to another feature of the invention, these BACKGROUND OF THE INVENTION 5 means operate so that if the circuit controller is out of
This invention relates to circuit controls, and particu- sequence due to a loss of power, the switching action larly to circuit controllers of the kind which initiate a controlled by a reversal of the physical condition decontrolled action in response to a physical condition energizes the load.
such as illumination, temperature, humidity, baromet- According to another feature of the invention, the ric pressure, etc., and the control action is terminated 10 circuit controller timing is selected to be shorter than on the basis of time tne cycling time °f the physical condition. Thus the
A typical application for such a device occurs in difference in time can determine the rate per physical regulation of outdoor lighting equipment that is in- condition cycle at which the circuit controller resyntended to illuminate an area during its normally used 1S fhron.zes itself. Under any set of circumstances the evening or nighttime hours. One available type of de- 15 load 18 TMt energized for a period of time longer than . . . , , , iU „ -i- the operation of the physical condition controlled
vice is interposed between the current carrying lines switchin action
and a load. It is composed of a photosensitive element TManotheI feature of the invention facili
that causes a relay to permit actuat.on of the lights at ^ afg ... tQ tufn Qn ^ u ht dufi the eafl sunset m response to the d1m1mshingamb.ent sunlight. 20 mornj hours in ^ wimer momhs Jhese ... At sunrise the photocell responds to the increasing turn on the lights at a predetermined number of hours ambient light and causes the relay to cut off power to after sunsgt unti, ^unrise
the lighting equipment. Such devices are satisfactory These and other features of the invention are pointed but tend to waste substantial amounts of current during out in the daims other objects and advantages of the the early morning hours when the illuminated area is 25 invention will become evident from the following deunused. tailed description when read in light of the accompany
Other types of devices for actuating loads in response jng drawings, to physical conditions are illustrated in U.S. Pat. Nos.
3,091,723 and 3,350,581. One of these systems is capa- BRIEp DESCRIPTION OF THE DRAWINGS
ble of solving the problem of energy waste by energiz- 30 FIG. 1 is a circuit diagram of a system embodying ing the light only for a predetermined period of time features of the invention.
after sunset. However, such a system fails to consider FIGS. 2 through 6 are graphs illustrating the operatchanges in the times of sunrise and sunset throughout ing conditions, relative to time, of various members the year. If, during the summer, the timing mechanism utilized in FIG. 1.
used is set to turn off the lights 5 hours after a 9 P.M. 35 FIG. 7 is a graph illustrating the times of sunrise and
summer sunset, the same timing mechanism would sunset, as well as the operating time of a load in FIG. 1
extinguish the light 5 hours after a 5 P.M. winter sunset, during various months of the year.
namely at 10 P.M. Such a system is not completely FIG- 8 is a schematic diagram of another system
satisfactory if the illuminated facilities are to be used embodying features of the invention.
until 2 A.M. On the other hand, accommodating the 40 FIGS. 9 through 13 are respective graphs illustrating
timing mechanism to a 5 P.M. winter sunset, so that it the operating conditions, relative to time, of various
would extinguish the lights 9 hours later at the desired members in the system of FIG. 8.
time of 2 A.M., would result in illumination throughout FIG- 14 ,s a circuit diagram of still another system
the night and after sunrise during the summer months. eTM*°dcy,?l T^t £ invenut,on; . u .
An object of this invention is to improve condi- 45 fIGS- }S throuSh 20 are graphs illustrating the time tioninitiated load-controlling systems. » SeTSSIi F?G° ...
Another object of the invention is to alleviate the „,._ . e ■ c .t.
c J j-rr- i»- FIG. 21 is a circuit diagram of a variation of the
aforementioned difficulties. ■ ■» • ,a< c » * »l '•
A .i . r.. • x- ■ . j circuit in FIG. 14, also embodying features of the in
Another object of the invention is to provide means 50 ventjon. and
which can be added to existing means for controlling ^JJJ; JJ ... 2? are gfaphs ulustrating the time such Loads. relationships of the operation of various components of
SUMMARY OF THE INVENTION the system in FIG. 21.
According to a feature of the invention, these objects 55 DETAILED DESCRIPTION OF PREFERRED are attained in whole or in part, by causing a detector EMBODIMENTS to exhibit one mode in response to a cyclical physical In FIG ^ two power hnes L and N carrying electrical condition such as light or darkness, and another mode p0wer, serve to energize a load LD such as a bank of in response to absence of the condition in response to street lights. A conventional optical light control OLC one mode shifting a circuit controller from one mode to 60 an(j an intermediate regulating system RS, also eneranother, and then continuing the controller's second gjzed by the lines L and N through suitable plug or mode for a definite period of time less than the cycle socket connectors CC, intervene between the line L time, during which the load is energized only when and the load LD to allow the load to be energized only both the detector controlled by the change in physical during specified periods after sunset, condition and the circuit controller that is energized by 65 This embodiment of the invention particularly conthe detector are both in the second mode. The load is cerns energizing street lights in response to changes in de-energized by either the detector or the circuit drop- illumination. However, it should be recognized that the ping back into the first mode. same kind of system can be used for energizing any
type of load in which the control action is initiated in response to any type of physical condition, such as change in illumination, pressure, humidity, temperature, etc. Thus, the load can be in the form of a sprinkler system which responds to changes in humidity detected by a humidity sensitive device in place of the photosensitive device shown in FIG. 1.
In the control OLC, a photosensitive element P exhibits a low resistance in response to the light occurring during daylight hours so that lines L and N pass current through a winding kl of a relay. The current opens normally closed contacts kl of the relay as shown in FIG. 2. At the sunset, when daylight hours end, winding Kl is de-energized and contacts kl close.
During the daylight hours, with the regulating system RS the lines L and N rotate a motor M through normally closed contacts kl of a relay having a winding K2. For simplicity the windings Kl and K2 are also referred to as coils Kl and K2 or just relays Kl and K2. The "normally closed" condition refers to the fact that the contacts are closed for passage of current when the relay windings are unenergized. The coil K2 is de-energized during daylight hours as shown in FIG. 3 because during these hours the contacts kl are open.
The high portion of a motor latching cam CM1 rotated by the motor M is positioned relative to motor latching contacts Ml to close the contacts Ml shortly after closing of contacts K2 at sunrise has started the motor M as shown in FIG. 4. The contacts Ml keep the motor M running even after contacts kl open as shown in FIG. 4. The speed of the motor M and the high portion of the latching cam CM1 is selected to keep the motor running for a period of time less than the cycle between sunrise and sunrise.
A timing cam CM2 closes normally open timing contact M2 for a predetermined time period. This time period is selected to start with closing of the contacts Ml, namely shortly after sunrise, and to extend to anywhere between 10 p.m. and 2 a.m. as shown in FIG. 5. The lines L and N energize the load LD when both contacts kl and M2 are closed simultaneously. This occurs from sunset to the end setting from 10 p.m. to 2 a.m. determined by the cam CM2. The cams CM1 and CM2 are fixed relative to one another and driven by the motor M.
The system is initially set to operate so that the cams CM1 and CM2 cause the contacts to be open just before sunrise. The cams CM1 and CM2 are also set to cause the motor to turn on the contacts Ml shortly before the contacts M2 and to cause the contacts Ml to open after the contacts M 2.
Thus in operation, sunrise lowers the resistance of the element P enough to energize relay Kl, thereby opening contacts A:l. This allows relay K2 to permit contacts kl to close and start the motor M. After a short rotational delay, cam operated contacts Ml and M2 close. Contacts Ml latch the motor and keep it energized even after contacts kl have opened. Contacts M2 enable the load without energizing it. At sunset the impedence of the element P becomes sufficiently high to de-energize the winding Kl and allow contacts H to close. This energizes relay K2 thereby opening contacts kl. The closing of contacts kl energizes the load LD. Thus, the load which is in the form of a bank of lamps is lit at sunset.
The lamp load LD continues to be lit until the time set for extinction by the cam CM2. At that time, with the rotational delay determined by the speed of the
motor and the cam, the contacts M2 open and de-energize the load LD. After some rotational delay, the contacts Ml open, thereby de-energizing the motor. The circuit stays in this quiescent state until start of
5 operation of the next sunrise.
In this manner the lamps forming the load LD are lit from sunset to some specified hour during the night. If the power source supplying the lines L and N is disabled for a period of time, the motor remains in posi
10 tion while the physical conditions produced by sunrise and sunset continue. If power is restored within a time period less than the difference between 24 hours and the total cycle of the regulating system RS, the motor stops before the next sunrise. At the next sunrise the
15 system again starts in synchronism with the sunrise sunset sequence. Thus, even with normally expectable power failures, the system maintains its normal operating sequence. In unusual circumstances, the power failure may stop
2° the motor M long enough to keep the contacts Ml and M2 for a period of time beyond the next sunrise. Under these circumstances, the contacts kl keep energizing the motor M even after the contacts Ml have opened. Because the operating period of the contacts Ml are
25 longer than the period during which the contacts kl are open, the contacts Ml keep the motor operating even after the contacts kl open. During this malfunction, the contacts kl and M2 energize the load throughout the night from sunset to sunrise. This provides a fail-safe
30 system for maintaining lights, although considerable energy may be wasted because of the excessive use.
The continuous operation of the motor by virtue of the overlapping operation of the contacts kl and Ml, periodically opens the contacts Ml. Since the total
35 rotating cycle of the motor Ml is less than the 24 hour cycle from sunrise to sunrise, after a few cycles, the open condition of the contacts ml will coincide with the open condition of the contacts kl. The motor will then not restart until the next sunrise. In this way, the
40 motor resynchronizes itself to the physical condition actuating the system.
FIG. 7 illustrates the time period of sunrise and sunset for the months of the year (shown along the ordinate). The graph also shows the periods during which
45 the load is on during normal operation.
An advantage of the embodiment of the invention shown in FIG. 1, resides in the ability to insert the regulating system RS between a conventional outdoor lighting control OLC and its usual load connection
50 while imparting the operating abilities of the regulating system RS to the overall network.
FIG. 8 illustrates another embodiment of the invention. Here the lines L and N energize a direct current relay KA through a, rectifier bridge composed of diodes
55 Dl. The photoelectric element P again controls energization of the relay KA. In FIG. 8, instead of using two relays, the relay KA simultaneously operates normally open relay contacts Kla and normally closed relay contacts Klb. In normal operation just prior to sunrise,
60 the contacts K16 are closed, the contacts Kla are opened, and the contacts Ml and M2 of the cams CM1 and CM2 driven by the motor M are both open. At sunrise increasing current through the photosensitive element P energizes the relay KA. This opens contacts
65 Klfc and closes contacts Kla. The closed contacts Kla allow the lines L and N to energize the motor M. After a short rotational delay the cams CM1 and CM2 close the contacts Ml and M2. The contacts Ml latch the
5 6 motor M in its energized mode. The contacts M2 en- ceeds 12 hours, the cam CM2 closes the contact M2 12 able or set up the lamp load LD. At sunset, the high hours after sunset. Since this occurs before sunrise and impedance of the element P de-energizes the relay KA the contact Kl is closed, the load LD is activated until which in turn opens the contacts Kla and closes the sunrise when Kl opens.
contacts Klb. These then energize the load. The afore- 5 When the load LD is in the form of street lamps the mentioned operations can be seen from FIGS. 9, 10, circuit of FIG. 21 affords all the advantages of that in 11, 12, and 13. FIG. 14 with the additional capability of furnishing
As shown in FIG. 12, after the pre-established rota- light in the pre-sunrise hours. This ability is important tional delay, the contacts M2 open. This may, for ex- during yearround daylight savings time. In northern ample, occur at 1 A.M. Opening of the contacts M2 10 regions of the U.S. daylight does not begin until perde-energizes the load. After a further rotational delay haps 8 or 9 A.M. in mid-winter. Thus the additional contacts Ml open to stop the motor M. The circuit light helps early travellers, schoolchildren, and others, stays in this quiescent state until the start of operation This is especially important in the Western part of any at the next sunrise. time zone.
The circuit of FIG. 8 exhibits the advantages avail- 15 The invention effectively improves condition initiable from the circuit of FIG. 1. However, here, the ated load controlling systems. It avoids the waste of relay KA may be a simpler direct current relay rather energy inherent in failing to extinguish a load operation than that conventionally used for outdoor lighting con- when its use is no longer needed before a load reversal, trols. The bridge formed by diodes Dl and filter capaci- For example, it avoids the waste of energy during early tor, CI, serves to operate the relay KA. 20 morning hours when an illuminated area is not used. It
FIG. 14 illustrates another circuit utilizing a conven- also adjusts itself to changes in the cyclical pattern such tional outdoor lighting control OLC with a regulating as changes in sunrise and sunset throughout the year, system RS that serves as a timer adapter between the Thus in the wintertime the length of the illuminated normal load arrangement and the usual control OLC. period is increased, while during the summer the length In FIG. 14 the control action is initiated at sunset. At 25 of the illuminated period is decreased, sunset the high impedance of the photosensitive ele- The invention permits the system to return to its ment P de-energizes the coil Kl thereby closing the normal operating sequence even after it has been discontacts Kl. This passes current from the line L abled for a period of time. This is so even in the unusual through the contacts Kl and the contacts Mlb through circumstances where the power failure may extend the motor M to start it. The operation of contacts kl, 30 beyond one or more condition reversals. Mlb, Mia, and M, are illustrated in FIGS. 15, 16, 17, While embodiments of the invention have been deand 18. As shown in FIGS. 16 and 17, the contacts Mia scribed in detail, it will be obvious to those skilled in and Mlb are complementary. Thus during rotation the the art that the invention may be otherwise embodied contacts Mia are open when the contacts Mlb are without departing from its spirit and scope, closed and vice versa. The cam CM1 closes the 35 What is claimed is:
contacts Mia to latch the motor M in its operating 1. An apparatus for energizing a load from energy condition for a period less than the 24 hours, such as a carrying conductors, comprising detector means reperiod of 20 hours. sponsive to a cyclically recurring physical condition for
As shown in FIGS. 18,19 and 20, the timing contacts exhibiting a first mode in response to the physical conM2 are operated by the cam CM2 so that the contacts 40 dition and a second mode in response to the absence of M2 close before the motor stops, such as near noon, the condition, control means exhibiting a first mode and open some time between 9 P.M. and 1 A.M. Since and a second mode and coupled to said detector means the contacts M2 are closed at sunset, closing of the for shifting from the first mode to the second mode contacts Kl energizes the load at sunset, opening of the while the detector means is in the first mode, and for contacts M2 at their predetermined time between 9 45 shifting back to the first mode after a given time less P.M. and 1 A.M. de-energizes the load as shown in than the period of the cyclically recurring physical FIGS. 19 and 20. condition, and circuit means for coupling the detector
FIG. 21 illustrates a circuit corresponding to that in means and the conductors and the control means and FIG. 14. The circuit of FIG. 21 differs from that in FIG. the load in circuit relationship; said circuit means being 14 in that cam CM2 includes a second rise R2. The 50 responsive to said control means being in the second latter is positioned relative to the cam CM1 so that the mode, and said detector means simultaneously being in rise R2 closes the contacts M2 a predetermined num- the second mode in response to the absence of the ber of hours, e.g. 12 hours, after the cam CM1 closes condition, for connecting the lines across the load, the contacts Mia at sunset. It holds the contacts M2 2. An apparatus as in claim 1, wherein said control closed for about five hours. Thus with one exception 55 means shifts from the first to the second mode in rethe circuit of FIG. 21 operates the same as that of FIG. sponse to the detector means entering the first mode. 14. FIGS. 22 to 27 illustrate the operation of members 3. An apparatus as in claim 1, characterized in that Kl, Mlb,.Mla, M, M2, and LD respectively. However, said control means includes a motor responsive to the in FIG. 21, as shown in FIGS. 26 and 27, the contacts first of said signals, cam means coupled to said motor, M2 are closed 12 hours after sunset for a period of 60 contact means responsive to the cam means for latchabout 5 hours. ing the motor so it remains energized and second
In operation, during the summer months when the contact means responsive to the cam means for maininterval between sunset and sunrise is less than 12 taining the control means in its second mode for the hours, the second rise R2 in the cam CM2 and the given time, said cam means when moved by the motor operation of M2 have substantially no effect upon the 65 having a period less than the cyclically recurring physiload LD. This is so because the contact Kl opens be- cal condition so that the motor is latched for a period of fore the contact M2 in series therewith closes. In the time less than the cyclically recurring physical condiwinter months, when the sunset to sunrise interval ex- tion.
4. An apparatus as in claim 2, characterized in that said control means includes a motor responsive to the first of said signals, cam means coupled to said motor, contact means responsive to the cam means for latching the motor so it remains energized and second contact means responsive to the cam means for maintaining the control means in its second mode for the given time, said cam means when moved by the motor having a period less than the cyclically recurring physical condition so that the motor is latched for a period of time less than the cyclically recurring physical condition.
5. An apparatus as in claim 1, wherein said detector means includes a photosensitive element and the physical condition to which said detector means exhibits its first mode is darkness.
6. An apparatus as in claim 1, wherein said detector means includes a photosensitive element and the physical condition to which said detector means exhibits its first mode is light.
7. An apparatus as in claim 1, wherein said detector means includes an alternating current actuable relay having contacts.
8. An apparatus as in claim 1, wherein said detector means includes a direct current relay and a rectifying circuit for energizing the relay.
9. An apparatus as in claim 1, characterized in that said detector means includes a detector and a relay responsive to said detector, said relay having contacts, said control means including a motor responsive to the first of said signals, cam means coupled to said motor contact means responsive to the cam means for latching the motor so it remains energized for a given period, and second contact means responsive to the cam means for maintaining the control means in its second mode for a given time.
10. An apparatus as in claim 7, characterized in that the contacts of the relay of said detector means are connected in series with the second contact means of said control means.
11. An apparatus as in claim 1, wherein the control means includes means for again shifting to the second mode after the shift back to the first mode and a predetermined period after the detector means shifts to the second mode.
12i An apparatus for regulating the current flow to a load from a power line through a detector switch which assumes alternate switching modes in response to a cyclically recurring physical condition, comprising a control switch, circuit means for connecting the control switch to the load and to the detector switch, an actuable clocking device, a first timing switch connected to the clocking device, a second timing switch connected to the clocking device, and coupling means coupling said first timing switch to said circuit means and said control switch to said clocking device, said coupling means causing said first timing switch to actuate said clocking device in response to one of two current flow statuses in said circuit means and causing the second timing switch to latch the clocking device in the actuated condition for a predetermined period extending into the second of the two current flow statuses of said circuit means and closing the control switch in response to operation of the clocking device for a second predetermined period during actuation of the clocking device.
13. An apparatus as in claim 12, wherein the first of the two statuses of current flow in said circuit means is
a flow of current and the second status is the absence of current.
14. An apparatus as in claim 12, wherein the first of the two statuses of current flow in said circuit means is
5 the absence of current and the second of the two statuses is the presence of current.
15. An apparatus as in claim 12, wherein two conductors are adapted to be connected to power lines and said first timing switch and said second timing switch
10 when respectively closed connect said clocking device between said conductors.
16. An apparatus as in claim 15, wherein the first current status of said circuit means is the absence of current and said coupling means includes a relay coil
15 which when unactuated closes the first timing switch, said coupling means including a time actuated switch closer responsive to said clocking means for closing said second timing switch while said first timing switch actuates said clocking mechanism and for retaining the
20 second timing switch closed for a predetermined period from the actuation of said clocking device, said coupling means including a second time actuated switch closer responsive to said clocking device for closing the control switch for the second predetermined time dur
25 ing closure of the control switch.
17. An apparatus as in claim 16, wherein said clocking device is a motor and said switch closers are cams coupled to the motor.
18. An apparatus as in claim 12, wherein said first 30 current status is the absence of current and wherein
said first timing switch connects said clocking mechanism to said circuit means, further comprising a conductor adapted to be connected to the line, said second timing switch when closed connecting said clocking
35 mechanism to-the conductor, said coupling means including a first time controlled switch closer for alternately closing said first and second timing switches so that said first timing switch is closed during the first status and remains closed through a portion of the
40 second status and said second timing switch is closed during other times, said coupling means setting said closers so that said clocking mechanism starts during the second current status and ends partially through the first current status, said coupling means including a
45 third switch closer closing said control switch during the time that said second timing switch is closed and during the first status, said third closer closing said coupling means for the second predetermined time.
19. An apparatus as in claim 18, wherein said third 50 closer closes said control switch a third given period
after actuation of said clocking device for a supplemental given time period in addition to the second predetermined period.
20. An apparatus as in claim 19, wherein said clock55 ing device is a motor and said coupling means include
21. An apparatus as in claim 12, wherein the coupling means is adapted to close the second timing switch for a time less than a cycle of the cyclically
60 recurring physical condition.
22. An apparatus for energizing light from energy carrying conductors, comprising light detector means responsive to cyclically recurring daylight for switching into a nonconductive open mode in response to day
65 light and a conductive closed mode in response to the absence of daylight, a control switching arrangement exhibiting a nonconductive open mode and a conductive closed mode and coupled to said detector means