US4064546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protection circuits
Assignee: Orkem SA
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Filing: 1976-06-16
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Granted: 1977-12-20
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Expires: 1996-06-16
Abstract
Abstract A protection circuit is provided which incorporates a reed relay whose contacts form the circuit breaker of an electrical appliance. The winding of the reed relay is supplied with a rectified alternating current derived from a current transformer coupled to the supply line to the appliance. In order to avoid periods of zero current in the winding, the winding is also supplied with a rectified alternating current from a source which is out of phase with that supplying the supply line. Failure of the current on the line will cause the contacts to open. Preferably the relay has a set of self latching contacts to prevent re-energization of the winding once de-energized. A manually operable reset switch is provided in series with the self latching contacts.
Inventors
- 👤 Thadee Domanski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:40
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/027; G; G01; G01R; G01R19/00; G01R19/165; G01R19/16504; G01R19/16509; H02H3/12; H02H3/13
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
234 words
A protection circuit for protecting an electric appliance supplied through a power supply line, comprising a reed switch having a set of magnetizable contact members, a set of contacts, each contact being mounted on a respective one of the contact members, a capsule housing the contact members and the set of contacts, and winding means supported by the capsule and energizable to produce a magnetic field for causing relative movement of the two contact members between first and second relative positioned settings, generating means coupled to the power supply line to generate a current in response to the current drawn by the appliance through the power supply line, first rectifying means electrically connected to the generating means for rectifying the generated current and supplying the rectified current to energize the winding means, means supplying a current out-of-phase with the current generated by the generating means, and second rectifying means connected to the current supply means to rectify the out-of-phase current and supplying the current to the winding means in a sense to produce a magnetic field assisting that produced by the generating means, whereby the composite magnetic field generated will maintain the set of contacts in the said first setting while the supply of both currents to the winding means is sustained but will switch the contacts to the second setting when the supply of one of said currents to the winding means fails.
Claim 2
Dependent Claim
234 words
A protection circuit for protecting an electric appliance supplied through a power supply line, comprising a reed switch having a set of magnetizable contact members, a set of contacts, each contact being mounted on a respective one of the contact members, a capsule housing the contact members and the set of contacts, and winding means supported by the capsule and energizable to produce a magnetic field for causing relative movement of the two contact members between first and second relative positioned settings, generating means coupled to the power supply line to generate a current in response to the current drawn by the appliance through the power supply line, first rectifying means electrically connected to the generating means for rectifying the generated current and supplying the rectified current to energize the winding means, means supplying a current out-of-phase with the current generated by the generating means, and second rectifying means connected to the current supply means to rectify the out-of-phase current and supplying the current to the winding means in a sense to produce a magnetic field assisting that produced by the generating means, whereby the composite magnetic field generated will maintain the set of contacts in the said first setting while the supply of both currents to the winding means is sustained but will switch the contacts to the second setting when the supply of one of said currents to the winding means fails.
Claim 3
Dependent Claim
70 words
A circuit according to claim 1, wherein the winding means comprises a first winding having two coils, and the first rectifying means comprises two diodes, one diode being connected to one said coil to supply alternate half cycles of the current from the generating means to the said one coil, and the other diode being connected to the other said coil to supply the other coil with intervening half cycles.
Claim 4
Dependent Claim
37 words
A circuit according to claim 2, wherein the power supply line comprises one phase of a polyphase supply and the means supplying the out-of-phase current comprises second generating means coupled to another phase of the polyphase supply.
Claim 5
Dependent Claim
182 words
A protection circuit for protecting an electrical appliance connected to a polyphase supply, comprising: means coupled to each phase of the polyphase supply to generate currents corresponding to the currents drawn by each phase of the polyphase supply, rectifying means connected to each generating means rectifying the current generated thereby, and a reed relay having a set of contacts connected as a circuit breaker for the appliance, and winding means connected to the rectifying means to receive the rectified currents, the rectified currents supplied to the winding means all assisting in the generation of a magnectic field to close the set of contacts whereby in the event of current failure in one or more phases of the supply, the magnetic field will drop sufficiently to allow the contacts to open and so break the circuit of the appliance, and wherein the winding means comprises one coil for each phase of the polyphase supply, each coil being connected to receive the current from a corresponding said rectifying means, and wherein the rectifying means comprises a diode connected in a series with each coil.
Claim 6
Dependent Claim
182 words
A protection circuit for protecting an electrical appliance connected to a polyphase supply, comprising: means coupled to each phase of the polyphase supply to generate currents corresponding to the currents drawn by each phase of the polyphase supply, rectifying means connected to each generating means rectifying the current generated thereby, and a reed relay having a set of contacts connected as a circuit breaker for the appliance, and winding means connected to the rectifying means to receive the rectified currents, the rectified currents supplied to the winding means all assisting in the generation of a magnectic field to close the set of contacts whereby in the event of current failure in one or more phases of the supply, the magnetic field will drop sufficiently to allow the contacts to open and so break the circuit of the appliance, and wherein the winding means comprises one coil for each phase of the polyphase supply, each coil being connected to receive the current from a corresponding said rectifying means, and wherein the rectifying means comprises a diode connected in a series with each coil.
Claim 7
Dependent Claim
14 words
A circuit according to claim 4, wherein the coils are interconnected in star configuration.
Claim 8
Dependent Claim
63 words
A circuit according to claim 5, including a light emitting diode for each phase of the polyphase supply, and means connecting the diodes in star configuration and connecting the diode star configuration to receive the rectified current generated for each phase, whereby the failure of a diode to light is indicative of the current failure in a corresponding phase of the polyphase supply.
Claim 9
Dependent Claim
23 words
A circuit according to claim 4, wherein the winding means comprises a single coil connected to receive the sum of the rectified currents.
Claim 10
Dependent Claim
28 words
A circuit according to claim 4, including a variable resistor connected in series with the winding means to vary the level of current drawn by the winding means.
Claim 11
Dependent Claim
235 words
A protection circuit for protecting an electrical appliance connected to a polyphase supply in the event of a current failure in one or more phases of the polyphase supply, the circuit comprising: a relay switch having energizing winding means and a set of contacts connectable as a circuit breaker for the appliance and actuable in response to energization of the winding means, current transformer means coupled to each phase of the supply for detecting the presence of a current in each phase of the said supply, rectifying means connected to each current transformer means for rectifying the output of the current transformer means, and means feeding the currents from the rectifying means to the winding means in a sense to assist each other in producing a magnetic field for actuating the set of contacts, whereby the failure of current in at least one of the phases of the supply will cause at least a partial current failure in the winding means and therefore de-actuation of the contacts, and wherein the relay switch includes a second set of contacts connected by the feeding means in series with the winding means and the rectifying means, the second set of contacts constituting a self-latching set of contacts for the relay switch, whereby failure of current in at least one of the phases of the supply will interrupt the current path between the rectifying means and the winding means.
Claim 12
Dependent Claim
235 words
A protection circuit for protecting an electrical appliance connected to a polyphase supply in the event of a current failure in one or more phases of the polyphase supply, the circuit comprising: a relay switch having energizing winding means and a set of contacts connectable as a circuit breaker for the appliance and actuable in response to energization of the winding means, current transformer means coupled to each phase of the supply for detecting the presence of a current in each phase of the said supply, rectifying means connected to each current transformer means for rectifying the output of the current transformer means, and means feeding the currents from the rectifying means to the winding means in a sense to assist each other in producing a magnetic field for actuating the set of contacts, whereby the failure of current in at least one of the phases of the supply will cause at least a partial current failure in the winding means and therefore de-actuation of the contacts, and wherein the relay switch includes a second set of contacts connected by the feeding means in series with the winding means and the rectifying means, the second set of contacts constituting a self-latching set of contacts for the relay switch, whereby failure of current in at least one of the phases of the supply will interrupt the current path between the rectifying means and the winding means.
Claim 13
Dependent Claim
19 words
A circuit according to claim 9, including a resistor is connected in parallel with the second set of contacts.
Claim 14
Dependent Claim
39 words
A circuit according to claim 9, including a reset switch connected in parallel with the second set of contacts and operable to temporarily short-circuit the said second set of contacts in order to enable re-energization of the winding means.
Claim 15
Dependent Claim
127 words
A circuit according to claim 11, including a thyristor having a control electrode and an anode-cathode path, the anode-cathode path being connected in shunt with the said second set of contacts, a third set of relay contacts included in the relay switch means connecting the control electrode in series with the third set of contacts and connecting the winding means in series with the anode cathode path of the thyristor whereby when the winding means are de-energized the third set of contacts are open and the thyristor is capable of conducting currents from the rectifying means in a sense to cause energization of the winding means, whereafter, in response to energization of the winding means the third set of contacts are closed and the thyristor rendered non-conductive.
Claim 16
Dependent Claim
78 words
A circuit according to claim 9, including a charge/discharge circuit, and means connecting the charge/discharge circuit in parallel with the winding means, the charge/discharge circuit being chargeable when the winding means is energized and dischargeable through the winding means in the absence of any other energizing current, whereby to maintain the winding means energized during temporary discontinuities in the currents of the power supply and thus render the protection circuit substantially insensitive to transients in the power supply.
Claim 17
Dependent Claim
64 words
A circuit according to claim 13, whereby the charge/discharge circuit comprises a resistor, a capacitor, a diode, and means connecting resistor and capacitor in series across the winding means and connecting the diode in parallel with the resistor in such a sense that the charging of the capacitor takes place through the resistor but the discharging of the capacitor takes place through the diode.
Claim 18
Dependent Claim
75 words
A circuit according to claim 14, wherein the relay means includes a fourth set of contacts controlled by the winding means, and means connecting the fourth set of contacts in shunt with the capacitor to provide a discharge path for the capacitor, the set of contacts being closed in response to the current supplied to the winding means exceeding a predetermined level, thereby to prevent the capacitor charging while the current exceeds the predetermined level.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |