US3846641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for a plurality of loads
Assignee: Hochiki Corp
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Filing: 1973-09-10
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Granted: 1974-11-05
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Expires: 1993-09-10
Abstract
Abstract In a control system wherein a plurality of loads are sequentially connected in parallel across supply conductors, each load is connected across the supply conductors through a switching circuit which is closed a predetermined interval after the application of an operating voltage, the loads in the second and succeeding stages are connected across the supply conductors through transfer switches which are operated in response to the operation of the loads in the preceding stages, a relay contact is connected in parallel with each transfer switch, and relay means is provided for each stage for opening the contact when the load and the switching circuit in that stage are energized, and for closing the contact after a predetermining interval. For the purpose of performing a conduction test of the whole system, the supply conductors are terminated with an impedance element, and a test voltage lower than the operating voltage is connected to the supply conductors at the time of the conduction test.
Inventors
- 👤 Y Eguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:20
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/04; G05B19/07; H; H03; H03K; H03K17/00; H03K17/28; H03K17/292
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
166 words
A control system for sequentially operating a plurality of loads connected in parallel across supply conductors, said control system comprising a plurality of switching circuits for respective loads, each one of said switching circuits being closed a predetermined interval after the application of the operating voltage for connecting the associated load to said supply conductors, a plurality of transfer switches for connecting the loads to said supply conductors in the second and succeeding stages, means responsive to the operation of the load in the preceding stage for operating the transfer switch of the succeeding stage to connect the load of said succeeding stage across said supply conductors, a plurality of relay contacts respectively connected in parallel with said transfer switches, relay means connected in preceding stages for opening said contacts when the loads and said switching circuits in the preceding stages are energized, and for closing said contacts after a predetermined interval, and a terminal impedance element connected across the end terminals of said supply conductors.
Claim 2
Dependent Claim
166 words
A control system for sequentially operating a plurality of loads connected in parallel across supply conductors, said control system comprising a plurality of switching circuits for respective loads, each one of said switching circuits being closed a predetermined interval after the application of the operating voltage for connecting the associated load to said supply conductors, a plurality of transfer switches for connecting the loads to said supply conductors in the second and succeeding stages, means responsive to the operation of the load in the preceding stage for operating the transfer switch of the succeeding stage to connect the load of said succeeding stage across said supply conductors, a plurality of relay contacts respectively connected in parallel with said transfer switches, relay means connected in preceding stages for opening said contacts when the loads and said switching circuits in the preceding stages are energized, and for closing said contacts after a predetermined interval, and a terminal impedance element connected across the end terminals of said supply conductors.
Claim 3
Dependent Claim
73 words
The control system according to claim 1, which further comprises a first source for supplying a normal operating voltage for said loads, a second source having a test voltage lower than said normal operating voltage, a transfer switch for selectively connecting said supply conductors across either one of said first and second said sources, and a meter for measuring the current flowing through said supply conductors when said second source is connected thereto.
Claim 4
Dependent Claim
75 words
The control system according to claim 2 wherein, each one of said respective switching circuits comprises a silicon controlled rectifier connected in series with one load, a Zener diode connected to supply a gate voltage to said silicon controlled rectifier, a CR time constant circuit for applying a driving voltage for said Zener diode a predetermined interval after energization of the switching circuit, said Zener diode not becoming conductive when supplied with said test voltage.
Claim 5
Dependent Claim
162 words
The control system according to claim 3 which, further comprises a plurality of protective circuits, each connected parallel with the serially connected with one load and one switching circuit and comprising a relay coil for operating said contact, a transistor connected in series with said relay coil, and a CR time constant circuit and a Zener diode which are connected in series for applying a control current to said transistor, said last-named Zener diode becoming conductive when applied with said operating voltage for rendering conductive said transistor within the delay time of said switching circuit, said Zener diode becoming not conductive when applied with said test voltage which is lower than said operating voltage, and said last-named CR time constant circuit having a time constant which is predetermined such that said control current for said transistor is maintained for a interval somewhat longer than the operating time of said load and is then decreased to a value sufficient to interrupt said transistor.
References Cited (Backward Citations)
US3566147A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |