US3737671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demand controller
Assignee: WELLS RE
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Filing: 1972-05-18
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Granted: 1973-06-05
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Expires: 1992-05-18
Abstract
Abstract A demand controller which allows the application of power to be units to be selectively disconnected so as to assure that the power demand does not exceed preset limits. Since electrical power companies bill on a basis such that additional charges are made for maximum demand rates occurring during monitored intervals, substantial savings in power bills can be made by limiting the maximum demand. The present invention monitors the actual demand and compares it with the theoretical ideal maximum demand and disconnects loads when the actual demand exceeds the theoretical ideal demand over a standard time period. Provisions are made for synchronizing the demand controller with the time interval utilized by the power company to assure accurate control of the billing rates.
Inventors
- 👤 B Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:36
CPC Classifications
G; G01; G01R; G01R11/00; G01R11/56; G01R11/60
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
195 words
Apparatus for synchronizing the demand period of a utility meter with a demand meter comprising: a demand meter with a clock motor; time interval contacts controlled by said clock motor; an ideal demand pointer driven by said clock motor and to periodically return it to an initial position; an actual demand pointer mounted in said demand meter; an incremental advance means connected to said actual demand pointer and energized by a signal indicative of power usage; a return to zero means for returning said actual demand pointer to an initial position; a pair of power terminals; a pair of synchronizing contacts in series with said clock motor between said power terminals; a synchronizing relay connected to said time interval contacts and to said pair of synchronizing contacts to open them when said synchronizing relay is energized; a pair of time interval signal contacts closed by a signal from said utility; and control means connected to said time interval signal contacts and first control contacts connected in circuit with said synchronizing relay and controlled by said control means to prevent energization of said synchronizing relay when said time interval occurs before said time interval contacts close.
Claim 2
Dependent Claim
195 words
Apparatus for synchronizing the demand period of a utility meter with a demand meter comprising: a demand meter with a clock motor; time interval contacts controlled by said clock motor; an ideal demand pointer driven by said clock motor and to periodically return it to an initial position; an actual demand pointer mounted in said demand meter; an incremental advance means connected to said actual demand pointer and energized by a signal indicative of power usage; a return to zero means for returning said actual demand pointer to an initial position; a pair of power terminals; a pair of synchronizing contacts in series with said clock motor between said power terminals; a synchronizing relay connected to said time interval contacts and to said pair of synchronizing contacts to open them when said synchronizing relay is energized; a pair of time interval signal contacts closed by a signal from said utility; and control means connected to said time interval signal contacts and first control contacts connected in circuit with said synchronizing relay and controlled by said control means to prevent energization of said synchronizing relay when said time interval occurs before said time interval contacts close.
Claim 3
Dependent Claim
83 words
Apparatus according to claim 1 wherein said control means comprises: a latch relay with a latch relay winding and a latch release winding; said latch relay winding receiving a signal from said utility indicative of the utility time interval and controlling said first control contacts to open them when energized; and a second pair of control contacts closed when said latch relay winding is energized and connected in series between said power terminals with said latch release winding and said time interval contacts.
Claim 4
Dependent Claim
82 words
ApParatus according to claim 2 wherein said control means includes: a time delay relay with a winding and time delay contacts; a third pair of control contacts closed when said latch relay winding is energized and connected between said power terminals in series with said winding of said time delay relay; a first pair of time delay contacts closed by said time delay relay a predetermined time after said relay is energized; and a lock-out circuit controlled by said time delay contacts.
Claim 5
Dependent Claim
13 words
Apparatus according to claim 3 wherein said lock-out circuit comprises a lock-out relay.
Claim 6
Dependent Claim
44 words
Apparatus according to claim 3 comprising a second pair of time delay contacts connected in series with said latch release winding, said second pair of control contacts and said time interval contacts and opened a predetermined time after said time delay relay is energized.
Claim 7
Dependent Claim
67 words
Apparatus according to claim 3 comprising: a fourth relay energized by a signal from said utility indicative of utility time interval and controlling a fourth pair of control contacts in series with said latch relay winding to energize it when said fourth relay is energized; and a fifth pair of control contacts in series with said latch release winding and opened when said fourth relay is energized.
Claim 8
Dependent Claim
35 words
Apparatus according to claim 6 including lock-out contacts controlled by the relative positions of said ideal demand pointer and said actual demand pointer and connected between said power terminals in series with said lock-out relay.
Claim 9
Dependent Claim
89 words
Apparatus according to claim 7 comprising: a fifth relay with its winding connected in series with said time interval contacts and said second pair of control contacts; a sixth relay with one side of its winding connected to one of said time interval contacts; sixth and seventh control contacts connected in parallel between the other side of the winding of said sixth relay and one of said power terminals with the sixth control contacts controlled by said sixth relay; and the seventh control contacts controlled by said fifth relay.
Claim 10
Dependent Claim
22 words
Apparatus according to claim 8 comprising eighth control contacts controlled by said sixth relay and connected in circuit with said synchronizing relay.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |