US4625309A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monitoring circuit with power-up interval safeguard for a microcomputer
Assignee: Robert Bosch GmbH
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Filing: 1983-11-03
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Granted: 1986-11-25
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Expires: 2003-11-03
Abstract
Abstract A capacitor (12) which, by its charge or discharge, times the interval between successive signals at a computer output point which is being monitored so as to provide a reset signal to the computer when the interval exceeds a predetermined normal value, is held in a charge condition which produces a reset signal to the computer component, for a predetermined time after power is turned on. In one embodiment a transistor in circuit with resistances and another capacitance is used for that function and in another embodiment an additional comparator responsive to the rise of the supply voltage up to a threshold value provides that function. The circuit can be designed to provide reset signals of either logic value (0 or 1).
Inventors
- 👤 Werner Nitschke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:11
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0703; G06F11/0751; G06F11/0754; G06F11/0757
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
155 words
Electric circuit apparatus for monitoring an electronic computer component which provides periodic signals at one of its outputs during normal operation, including a capacitor connected to a charge/discharge circuit controllable by said periodic signals and connected also to a comparator in such a manner that when the charge of said capacitor reaches a predetermined voltage value, said comparator provides a reset signal for said computer component, said apparatus including the improvement which comprises: circuit means (26,33) for maintaining said very same capacitor (12) at a condition of charge which corresponds to the provision of a reset signal at the output of said comparator (15), regardless of any signal at said output of said computer component, during a period beginning with the turning on of a supply voltage both for said apparatus and for said computer component and ending at a time dependent upon the value of said supply voltage and independent of said periodic signals.
Claim 2
Dependent Claim
155 words
Electric circuit apparatus for monitoring an electronic computer component which provides periodic signals at one of its outputs during normal operation, including a capacitor connected to a charge/discharge circuit controllable by said periodic signals and connected also to a comparator in such a manner that when the charge of said capacitor reaches a predetermined voltage value, said comparator provides a reset signal for said computer component, said apparatus including the improvement which comprises: circuit means (26,33) for maintaining said very same capacitor (12) at a condition of charge which corresponds to the provision of a reset signal at the output of said comparator (15), regardless of any signal at said output of said computer component, during a period beginning with the turning on of a supply voltage both for said apparatus and for said computer component and ending at a time dependent upon the value of said supply voltage and independent of said periodic signals.
Claim 3
Dependent Claim
30 words
Circuit apparatus according to claim 1 in which said circuit means comprise a semiconductor switch (26) controlled by the value of the supply voltage through a resistance-capacitance circuit branch (27-29).
Claim 4
Dependent Claim
46 words
Circuit apparatus according to claim 2 in which said semiconductor switch (26) is connected in parallel with said capacitor (12) and is connected to said resistance-capacitor circuit branch (27-29) in such a way that said semiconductor switch (26) becomes nonconducting after a prescribed period of time.
Claim 5
Dependent Claim
98 words
Circuit apparatus according to claim 1 in which said circuit means comprises a second comparator (33) having its inputs connected in a resistive circuit connected to said supply voltage such that the output condition of said second comparator (33) changes when the supply voltage reaches a predetermined voltage threshold, the output of said second comparator being connected to said capacitor in such a way that upon the switching on of the supply voltage, said capacitor (12) is at first short-circuited by the output of said second comparator (33) and remains short-circuited until the supply voltage reaches said threshold.
Claim 6
Dependent Claim
111 words
Circuit apparatus according to claim 4 in which a voltage divider (37,38) for the supply voltage is provided having a tap connected to one input of said second comparator and connected to a circuit branch (30, 31) connected to the output of said first comparator in such a way that when the supply voltage is less than said predetermined threshold voltage after the output of said first comparator produces a reset signal, said capacitor (12) is put, by means of its connection to said second comparator (33), in the charge condition which produces a reset signal at the output of said first comparator (15) until the supply voltage reaches said threshold.
Claim 7
Dependent Claim
46 words
Circuit apparatus according to claim 5 in which through an element (30) of said circuit branch (30,31) said reset signal at the output of said first comparator (15) is furnished as a null signal through a resistance (31) to the tap of said voltage divider (37,38).
Claim 8
Dependent Claim
22 words
Circuit apparatus according to claim 6 in which a Zener diode (36) is interposed in series with or in said voltage divider.
Claim 9
Dependent Claim
28 words
Circuit apparatus according to claim 6 in which the part (38) of said voltage divider which is connected to ground is bridged by a second Zener diode (39).
References Cited (Backward Citations)
US4282574A
Cited
US4245315A
Cited
US4255789A
Cited
US4338599A
Cited
GB2035633A
Cited
US4418398A
Cited
US4400783A
Cited
US4399537A
Cited
US4541050A
Cited
US4528629A
Cited
US4433413A
Cited
US4512019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |