US4572966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Activity monitor, power-on clear circuit
Assignee: Boeing North American Inc
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Filing: 1983-12-22
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Granted: 1986-02-25
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Expires: 2003-12-22
Abstract
Abstract A power-on clear circuit is disclosed with a repetitive reset output for use with a microprocessor having a "heartbeat" activity monitor. The reset output is repeated at specified intervals until the activity monitor is sensed, at which time the reset output is disabled until the activity monitor is no longer detected.
Inventors
- 👤 Mark N. Hepworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:56
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/22; G; G06; G06F; G06F1/00; G06F1/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
A power-on clear circuit for an apparatus having an activity monitor capability comprising: a. a monostable multivibrator having a predetermined unstable timing characteristic, for monitoring activity of said apparatus; b. a first open collector comparator coupled to the output of said multivibrator for sensing its output; and c. a second open collector comparator coupled to the output of said first comparator and having a second timing characteristic for issuing a series of reset pulses at an output, the duration of each reset pulse a function of said second timing characteristic, and issuing during the stable condition of said monostable multivibrator; said reset signal input to said multivibrator for initializing said multivibrator, thereby allowing a full duration reset pulse to issue.
Claim 2
Dependent Claim
120 words
A power-on clear circuit for an apparatus having an activity monitor capability comprising: a. a monostable multivibrator having a predetermined unstable timing characteristic, for monitoring activity of said apparatus; b. a first open collector comparator coupled to the output of said multivibrator for sensing its output; and c. a second open collector comparator coupled to the output of said first comparator and having a second timing characteristic for issuing a series of reset pulses at an output, the duration of each reset pulse a function of said second timing characteristic, and issuing during the stable condition of said monostable multivibrator; said reset signal input to said multivibrator for initializing said multivibrator, thereby allowing a full duration reset pulse to issue.
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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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |