US5341282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for detecting short-circuiting of inductive load drive devices
Assignee: STMicroelectronics SRL
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Filing: 1992-04-08
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Granted: 1994-08-23
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Expires: 2012-04-08
Abstract
Abstract An inductive load drive device which has a switch defining an output terminal connectable to an inductive load between the output terminal and a reference potential line is provided. A first current recirculating branch is connectable parallel to the load and a control opens and closes the switch so that the load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase. The device detects a short-circuit between the output terminal of the control device and the reference potential line with a first current sensor for detecting current flow in the first recirculating branch during the first recirculating phase. A fault signaling circuit connected to the first current sensor produces a short-circuit signal in the absence of current in the first recirculating branch during the first recirculating phase.
Inventors
- 👤 Massimiliano Brambilla
- 👤 Giampietro Maggioni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:12
CPC Classifications
H; H01; H01H; H01H47/00; H01H47/22; H01H47/32; H01H47/325; H02; H02H; H02H3/00; H02H3/08; H02H9/00; H02H9/04; H02H9/045; H02H9/047
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
125 words
A circuit for detecting short-circuiting in an inductive load drive device having a switch defining an output terminal connectable to an inductive load between said output terminal and a reference potential line; at least a first current recirculating branch connectable parallel to the load; control means for opening and closing said switch, so that said load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase; said circuit comprising means for detecting a short-circuit between said output terminal of said switch and said reference potential line, said detecting means having a first current sensor for detecting current flow in said first recirculating branch during said first recirculating phase.
Claim 2
Dependent Claim
125 words
A circuit for detecting short-circuiting in an inductive load drive device having a switch defining an output terminal connectable to an inductive load between said output terminal and a reference potential line; at least a first current recirculating branch connectable parallel to the load; control means for opening and closing said switch, so that said load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase; said circuit comprising means for detecting a short-circuit between said output terminal of said switch and said reference potential line, said detecting means having a first current sensor for detecting current flow in said first recirculating branch during said first recirculating phase.
Claim 3
Dependent Claim
38 words
A circuit as claimed in claim 1, further comprising fault signaling means connected to said first current sensor for producing a short-circuit signal in the absence of current in said first recirculating branch during said first recirculating phase.
Claim 4
Dependent Claim
107 words
A circuit as claimed in claim 2 wherein said inductive load drive device has a second recirculating branch controlled by said control means in such a manner that said load, following said first recirculating phase, is supplied with current rising to a third predetermined value and falling in a second recirculating phase; and said detecting means further having a second current sensor for detecting current flow in said second recirculating branch during said second recirculating phase; said second current sensor being connected to said fault signaling means for producing said short-circuit signal in the absence of current in said second recirculating branch during said second recirculating phase.
Claim 5
Dependent Claim
46 words
A circuit as claimed in claim 2, wherein said first recirculating branch forms part of a recirculating loop comprising a recirculating line connecting said reference potential line to said switch, and said first sensor comprises a current mirror circuit in the path of said recirculating line.
Claim 6
Dependent Claim
68 words
A circuit as claimed in claim 4 wherein said current mirror circuit comprises a first diode-connected transistor connected between said reference potential line and said switch; and a second transistor having its base and emitter terminals connected respectively to the base and emitter terminals of said transistor, and its collector terminals connected to means for producing a first logic signal indicating the presence or absence of recirculating current.
Claim 7
Dependent Claim
37 words
A circuit as claimed in any one of the foregoing claims from 3 to 5, said second current sensor comprises a detecting line connected parallel to said second recirculating branch and comprising a second current mirror circuit.
Claim 8
Dependent Claim
62 words
A circuit as claimed in claim 6, wherein said second recirculating branch comprises a voltage-controlled switch having an enabling terminal receiving an enabling signal from a control element; and said detecting line comprises a controlled switch element having a control terminal connected to said control element and receiving said enabling signal; said switch element being series-connected to said second current mirror circuit.
Claim 9
Dependent Claim
68 words
A circuit as claimed in claim 6, said second current mirror circuit comprises a third diode-connected transistor in the path of said detecting line; and a fourth transistor having its base and emitter terminals connected respectively to the base and emitter terminals of said third transistor, and its collector terminals connected to converting means for producing a second logic signal indicating the presence or absence of recirculating current.
Claim 10
Dependent Claim
68 words
A circuit as claimed in claim 7, said second current mirror circuit comprises a third diode-connected transistor in the path of said detecting line; and a fourth transistor having its base and emitter terminals connected respectively to the base and emitter terminals of said third transistor, and its collector terminals connected to converting means for producing a second logic signal indicating the presence or absence of recirculating current.
Claim 11
Dependent Claim
16 words
A circuit as claimed in claim 2, wherein said fault signaling means comprises a delay element.
Claim 12
Dependent Claim
54 words
A circuit as claimed in claim 10, wherein said delay element comprises a capacitive element connected to a first input of a comparator for omparing the voltage of said capacitive element with a reference value, and for producing said short-circuit signal in the event said voltage of said capacitive element matches said reference value.
Claim 13
Dependent Claim
74 words
A circuit as claimed in claim 11 further comprising first logic means for producing a third recirculating logic signal indicating said first recirculating phase; said fault signaling means having a first logic circuit receiving said first and third recirculating logic signals and output connected to said capacitive element said first logic circuit producing a charge enabling signal in the absence of said first logic signal and in the presence of said third logic signal.
Claim 14
Dependent Claim
76 words
A circuit as claimed in claim 11 or 12 further comprising second logic means for producing a fourth recirculating logic signal indicating said second recirculating phase; said fault signaling means having a second logic circuit receiving said second and fourth recirculating logic signals and output connected to said capacitive element; said second logic circuit producing a charge enabling signal in the absence of said second logic signal and in the presence of said fourth logic signal.
Claim 15
Dependent Claim
116 words
An inductive load drive device comprising a switch defining an output terminal connectable to an inductive load between said output terminal and a reference potential line; at least a first current recirculating branch connectable parallel to the load; control means for opening and closing said switch, so that said load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase; and a detecting circuit for detecting a short-circuit between said output terminal and said reference potential line; said detecting circuit having a first current sensor for detecting current flow in said first recirculating branch during said first recirculating phase.
Claim 16
Dependent Claim
116 words
An inductive load drive device comprising a switch defining an output terminal connectable to an inductive load between said output terminal and a reference potential line; at least a first current recirculating branch connectable parallel to the load; control means for opening and closing said switch, so that said load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase; and a detecting circuit for detecting a short-circuit between said output terminal and said reference potential line; said detecting circuit having a first current sensor for detecting current flow in said first recirculating branch during said first recirculating phase.
Claim 17
Dependent Claim
41 words
A device as claimed in claim 14, wherein said detecting circuit comprises fault signaling means connected to said first current sensor, for producing a short-circuit signal in the absence of current in said first recirculating branch during said first recirculating phase.
Claim 18
Dependent Claim
102 words
A device as claimed in claim 15, further comprising a second recirculating branch controlled by said control means in such a manner that said load, following said first recirculating phase, is supplied with current rising to a third predetermined value and then decreasing in value during a second recirculating phase; said detecting circuit comprising a second current sensor for detecting current flow in said second recirculating branch in said second recirculating phase; said second sensor being connected to said fault signaling means for producing said short-circuit signal in the absence of current in said second recirculating branch during said second recirculating phase.
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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) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-22 | 2002-02-21 | 2002-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-22 | 2006-02-21 | 2006-08-23 | $7700.00 | Window Closed / Lapsed |