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US3899718A
Expired / Lapsed
US
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Method and arrangement for limiting the power dissipated in electronic components
Assignee: Siemens AG
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Filing: 1974-01-28
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Granted: 1975-08-12
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Expires: 1994-01-28
Abstract
Abstract A method and apparatus for limiting the dissipated power of an electronic component in case of excessive load current, in which the load current is first allowed to remain switched on as it increases above a threshold, the current then limited to a maximum value and the load current switched off, only if it remains above the threshold value for a predetermined period of time and after a second time interval, the current is automatically switched on again.
Inventors
- 👤 Ulrich Schafe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:03
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/025; H02H3/06; Y; Y10; Y10S; Y10S323/00; Y10S323/908
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
Apparatus for limiting the power dissipation of an electronic component coupled to a power source in the case of excessive load current comprising: a. means to detect a load current exceeding a predetermined threshold value and to provide a first output signal indicative thereof; b. means responsive to said first output signal to provide, after a first predetermined first time delay, a second output signal; c. said means further adapted to remove said output signal after a second predetermined time interval; d. means arranged between said power source and said electronic component responsive to said second output signal for interrupting the load current supplied to said component when said second output signal is present; and e. means interposed between said power source and said component to limit the maximum current flowing during said first predetermined time interval.
Claim 2
Dependent Claim
137 words
Apparatus for limiting the power dissipation of an electronic component coupled to a power source in the case of excessive load current comprising: a. means to detect a load current exceeding a predetermined threshold value and to provide a first output signal indicative thereof; b. means responsive to said first output signal to provide, after a first predetermined first time delay, a second output signal; c. said means further adapted to remove said output signal after a second predetermined time interval; d. means arranged between said power source and said electronic component responsive to said second output signal for interrupting the load current supplied to said component when said second output signal is present; and e. means interposed between said power source and said component to limit the maximum current flowing during said first predetermined time interval.
Claim 3
Dependent Claim
123 words
The arrangement according to claim 1 wherein said means responsive to said first output signal comprise: a. a bistable multivibrator having an adjustable automatically switching upper and lower switching threshold adapted to provide said second output signal when said upper threshold is reached and for removing said second output signal when said lower switching threshold is reached after said upper threshold has first been reached; b. a capacitor coupled between one side of said power source and the input to said multivibrator; c. means responsive to said first output signal to couple the other side of said power source to said capacitor to cause it to charge; and d. means responsive to the output of said second output signal to discharge said capacitor.
Claim 4
Dependent Claim
68 words
The arrangement according to claim 2 wherein said multivibrator coMprises first and second transistors having their emitters tied together and further including a first switch driven by said first transistor and adapted to change the threshold voltage present at the base of said first transistor between said upper and said lower threshold and a second switch driven by the second transistor and coupled to switch said load current.
Claim 5
Dependent Claim
39 words
The arrangement according to claim 2 wherein said means for detecting comprise a measuring resistor in the load circuit, the voltage drop of which is coupled to the base of a third transistor which is coupled to said capacitor.
Claim 6
Dependent Claim
30 words
The arrangement according to claim 4 wherein the discharge path of said capacitor contains a fourth transistor and a series resistor, said transistor and series resistor forming a current sink.
Claim 7
Dependent Claim
18 words
The arrangement according to claim 5 and further including means to cause said fourth transistor to always conduct.
Claim 8
Dependent Claim
17 words
The arrangement according to claim 6 wherein said first and second switches comprises fifth and sixth transitors.
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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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |