US4710645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for monitoring the state of an electric switch or an electric relay
Assignee: Societe des Telephones Ericsson SA
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Filing: 1986-05-28
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Granted: 1987-12-01
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Expires: 2006-05-28
Abstract
Abstract A device for monitoring the state of a relay comprises an electrical insulation transformer whose secondary winding is connected, through a rectifier, to the output terminals of the relay. The primary winding of the transformer is in series with an oscillator having an impedance greater than that of the primary winding when the relay is closed. A transistor receives a signal from the primary winding and delivers an on-off output signal representing the impedance across the terminals of the relay.
Inventors
- 👤 Pierre O. Doittau
- 👤 Herve Moal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:56
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/18; H01; H01H; H01H9/00; H01H9/16; H01H9/167; H03K17/08; H03K17/082; H03K17/0826; H01H47/00; H01H47/002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
119 words
A device for monitoring an operating state of an electrical switch having a pair of output terminals, said switch, when in a closed state, having an impedance across terminals thereof lower than the impedance when said switch is in an open state by several orders of magnitude, comprising: an insulating transformer having a first winding and a second winding; rectifier means for connecting the first winding across said terminals of the switch; oscillator means having an impedance substantially higher than that of said second winding when said switch is in closed condition and in electric series relation with said second winding; and analysing means connected to said second winding and responsive to a signal received from said second winding.
Claim 2
Independent Claim
119 words
A device for monitoring an operating state of an electrical switch having a pair of output terminals, said switch, when in a closed state, having an impedance across terminals thereof lower than the impedance when said switch is in an open state by several orders of magnitude, comprising: an insulating transformer having a first winding and a second winding; rectifier means for connecting the first winding across said terminals of the switch; oscillator means having an impedance substantially higher than that of said second winding when said switch is in closed condition and in electric series relation with said second winding; and analysing means connected to said second winding and responsive to a signal received from said second winding.
Claim 3
Dependent Claim
22 words
A device according to claim 1, wherein said oscillator has an oscillation frequency higher than the maximum switching frequency of said switch.
Claim 4
Dependent Claim
49 words
A device according to claim 1, wherein said second winding has an end terminal connected to said oscillator and a second end terminal connected to a reference potential and wherein said analysing means are connected to that end terminal of the second winding which is connected to the oscillator.
Claim 5
Dependent Claim
109 words
In combination with a solid state relay including a solid state switch having a control electrode and a control circuit having an oscillator connected to said control electrode through rectifying means, a switch operating state monitoring device comprising: an insulating transformer having a first winding and a second winding; rectifier means for connecting the first winding across said terminals of the switch; means having an impedance substantially higher than that of said second winding when said switch is in closed condition for continuously delivering a RF voltage to said second winding; and analysing means connected to said second winding and responsive to a signal recieved from said second winding.
Claim 6
Dependent Claim
109 words
In combination with a solid state relay including a solid state switch having a control electrode and a control circuit having an oscillator connected to said control electrode through rectifying means, a switch operating state monitoring device comprising: an insulating transformer having a first winding and a second winding; rectifier means for connecting the first winding across said terminals of the switch; means having an impedance substantially higher than that of said second winding when said switch is in closed condition for continuously delivering a RF voltage to said second winding; and analysing means connected to said second winding and responsive to a signal recieved from said second winding.
Claim 7
Dependent Claim
86 words
A static relay-monitoring device combination according to claim 4, wherein said oscillator of the control circuit also constitutes said oscillator means of the monitoring circuit and wherein said oscillator is connected to deliver two identical signals in phase opposition to the end terminals of the primary winding of a control transformer whose secondary winding is connected via rectifying means to said control electrode, said primary winding having a midpoint connected to control means for selectively insulating said midpoint or bringing said midpoint to a reference voltage.
Claim 8
Dependent Claim
31 words
A static relay-monitoring device combination according to claim 4, wherein said control circuit has an oscillator distinct from the oscillator of the monitoring system and which directly drives said control transformer.
Claim 9
Dependent Claim
24 words
A static relay-monitoring device combination according to claim 5, wherein said oscillator of the control circuit has a frequency in the hundred kHz range.
References Cited (Backward Citations)
US4438356A
Cited
US4634903A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-30 | 1991-06-01 | 1991-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-30 | 1995-06-01 | 1995-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-30 | 1999-06-01 | 1999-12-01 | $7700.00 | Window Closed / Lapsed |