EP0049633B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in and relating to electrical inverters
Assignee: Texas Instruments Ltd
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Filing: 1981-10-06
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Granted: 1985-07-10
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Expires: 2001-10-06
Abstract
No abstract record available.
Inventors
- 👤 Jeffrey Ian Robinson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 09:08
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3385; H02M3/33507; Y; Y02; Y02B; Y02B70/00; Y02B70/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
282 words
An inverter arranged to convert d.c. electrical energy into alternating electrical energy including:- (i) a resonant circuit (3, 4 ^ -Fig. 1) arranged to store electrical energy and to generate sinusoidal electrical oscillations, (ii) switch means having enabled and disabled states for effecting when in an enabled state charging of the resonant circuit (3, 4) with electrical energy from a d.c. electrical supply (1, 2), (iii) control means (8-Fig. 1) arranged to enable the switch means (5) to charge the resonant circuit (3, 4) periodically in synchronism with and to reinforce oscillations in the resonant circuit (3, 4) and to disable the switch means to stop charging of the resonant circuit (3, 4), and (iv) output circuit means (9, 10-Fig. 1) coupled to the resonant circuit (3, 4) arranged to supply electrical energy to a load circuit coupled to the output circuit (9, 10), characterised in that charging of the resonant circuit (3, 4) is effected by current-limiting switch means (5) capable of conducting current up to a set limit and of holding the current at the set limit and monitoring means (6, 7, 11-Fig. 1) are arranged to monitor the voltage across the current-limiting switch means (5) and conditions in the resonant circuit (3, 4) and to cause the control means (8) to enable the current-limiting switch means (5) only while the said voltage lies between first and second limits and is changing in a predetermined sense, and the monitoring means (6, 7,11) are arranged to cause the control means (8) to disable the current-limiting switch means (5) when the said voltage reaches the second limit consequentto current flow being held at the set limit by the current-limiting switch means (5).
Claim 2
Dependent Claim
282 words
An inverter arranged to convert d.c. electrical energy into alternating electrical energy including:- (i) a resonant circuit (3, 4 ^ -Fig. 1) arranged to store electrical energy and to generate sinusoidal electrical oscillations, (ii) switch means having enabled and disabled states for effecting when in an enabled state charging of the resonant circuit (3, 4) with electrical energy from a d.c. electrical supply (1, 2), (iii) control means (8-Fig. 1) arranged to enable the switch means (5) to charge the resonant circuit (3, 4) periodically in synchronism with and to reinforce oscillations in the resonant circuit (3, 4) and to disable the switch means to stop charging of the resonant circuit (3, 4), and (iv) output circuit means (9, 10-Fig. 1) coupled to the resonant circuit (3, 4) arranged to supply electrical energy to a load circuit coupled to the output circuit (9, 10), characterised in that charging of the resonant circuit (3, 4) is effected by current-limiting switch means (5) capable of conducting current up to a set limit and of holding the current at the set limit and monitoring means (6, 7, 11-Fig. 1) are arranged to monitor the voltage across the current-limiting switch means (5) and conditions in the resonant circuit (3, 4) and to cause the control means (8) to enable the current-limiting switch means (5) only while the said voltage lies between first and second limits and is changing in a predetermined sense, and the monitoring means (6, 7,11) are arranged to cause the control means (8) to disable the current-limiting switch means (5) when the said voltage reaches the second limit consequentto current flow being held at the set limit by the current-limiting switch means (5).
Claim 3
Dependent Claim
49 words
An inverter as claimed in claim 1, wherein the monitoring means (6,7, 11) is so arranged that when, in operation, the oscillations are of sufficient amplitude to cause zero potential difference to exist periodically across the current-limiting switch means (5), the said first limit potential difference is substantially zero.
Claim 4
Dependent Claim
115 words
An inverter as claimed in claim 2, wherein the monitoring means (6,7, 11) includes a first comparator (6) arranged to change its output state abruptly between two levels when the potential difference across the current-limiting switch means (5) passes through the second limit, a second comparator (7) arranged to change its state abruptly between two levels when the current in the resonant circuit (3, 4) reverses direction, and the control means (8) includes an AND gate controlled by the comparators (6, 7) arranged to enable the current-limiting switch (5) means only when the current flow from the electrical supply would be in such a sense as to reinforce oscillations in the resonant circuit (3, 4).
Claim 5
Dependent Claim
163 words
An inverter as claimed in claim 2, wherein the monitoring means (27 to 30,36 to 40i--Fig. 5) includes a first comparator (27, 36 to 40) arranged to change its output state abruptly between two levels when the potential difference across the current-limiting switch (12, 15, 18-Fig. 5) passes through the second limit, a second comparator (30) arranged to change its state abruptly between two levels when the potential difference across the current-limiting switch (12,15,18) means passes through zero, and control means (28, 29) controlled by the comparators (27,30,36 to 40) arranged to close the current-limiting switch means (12, 15, 18) while the potential difference lies between zero and the said second limit, wherein the current-limiting switch means (12, 15, 18) and the control means (28, 29) are so arranged that the current-limiting switch means (12, 15, 18) remains enabled after closure only when the voltage across the resonant circuit (3, 4) changes to be of the same sense as the electrical supply voltage.
Claim 6
Dependent Claim
102 words
An inverter as claimed in any one of claims 1 to 4, wherein, the current-limiting switch means (5) includes a charging transistor (12-Fig. 3) arranged to charge the resonant circuit (3,4), means arranged to block reverse current in the transistor (16-Fig. 3), a bleed transistor (15-Fig. 3) arranged to control operation of the charging transistor (12), and a current monitoring circuit (13, 14-Fig. 3) arranged to monitor current flow in the charging transistor (12) and to hold the charging current at the set current limit of the switch, the current monitoring circuit (13, 14) being arranged to control the bleed transistor (15).
Claim 7
Dependent Claim
35 words
An inverter as claimed in any one of claims 1 to 5, including means (17-Fig. 3) arranged to adjust the current limit of the current-limiting switch means in order to compensate for output voltage changes.
Claim 8
Dependent Claim
37 words
An inverter as claimed in any one of claims 1 to 6, including a start-up circuit (24-Fig. 4) which is arranged to be switched off by the operation of the current-limiting switch means (12, 15, 18-Fig. 4).
Claim 9
Dependent Claim
32 words
An inverter as claimed in any one of claims 1 to 8, wherein the resonant circuit (3, 4) includes an inductor (3) which is a primary winding of a transformer (3-Fig. 5).
Claim 10
Dependent Claim
22 words
An inverter as claimed in any one of claims 1 to 8, wherein the resonant circuit (3, 4) is a series-connected circuit.
Claim 11
Dependent Claim
15 words
A Power supply including an inverter as claimed in any one of the preceding claims.
References Cited (Backward Citations)
US4196469A
Cited
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