US3710186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal processing circuit
Assignee: US Philips Corp
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Filing: 1969-12-12
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Granted: 1973-01-09
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Expires: 1989-12-12
Abstract
Abstract A vehicle anti-lock brake control system includes a pick-up device that produces electric signals with a frequency proportional to the vehicle wheel speed. These signals are applied via an amplifier to a Frequency-D.C. converter that develops a voltage proportional to wheel speed. A signal processing circuit is responsive to this voltage to produce an output signal when the wheel deceleration rate exceeds a reference deceleration. The output of the signal processing circuit is applied via a power amplifier to energize a solenoid that initiates an anti-lock braking action. The signal processing circuit will subsequently deenergize the solenoid as a function of a given criterion related to the wheel movement, as determined by the voltage applied thereto from the converter. Possible criteria are that the reference deceleration is no longer exceeded, that the wheel has ceased to decelerate or has started to accelerate.
Inventors
- 👤 D Sharp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:11
CPC Classifications
B; B60; B60L; B60L3/00; B60L3/10; B60L3/106; B60L3/108; B60L3/102
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
264 words
A signal processing circuit comprising differentiating means for differentiating an applied electrical quantity which is a function of wheel rotational speed to produce a signal waveform which is a function of wheel deceleration, the signal processing circuit being responsive to produce an output signal when an instantaneous value of this signal waveform exceeds a reference value, determined by certain of the circuit parameter, said differentiating means comprising a first capacitor having an input side connected to a point of application in the circuit of an input voltage which is a function of wheel rotational speed an an output side connected to a base of a first, normally conductive, transistor, and a first resistor connected between said base and a voltage line, and also between the voltage line and said capacitor, the values of said first capacitor and first resistor determining said reference value and the arrangement being such that said first transistor is normally conductive due to the current flow in its base via said first resistor from the voltage line and that as the value of said input voltage at the input side of said first capacitor changes, due to increase in wheel deceleration, current through said first resistor is diverted from the base of said first transistor to the output side of said first capacitor until, when said reference value has been exceeded, so much of the current has been diverted that said first transistor is rendered nonconductive to cause a second, normally nonconductive, transistor to be rendered conductive to provide an output signal from the circuit at an output connection thereof.
Claim 2
Dependent Claim
264 words
A signal processing circuit comprising differentiating means for differentiating an applied electrical quantity which is a function of wheel rotational speed to produce a signal waveform which is a function of wheel deceleration, the signal processing circuit being responsive to produce an output signal when an instantaneous value of this signal waveform exceeds a reference value, determined by certain of the circuit parameter, said differentiating means comprising a first capacitor having an input side connected to a point of application in the circuit of an input voltage which is a function of wheel rotational speed an an output side connected to a base of a first, normally conductive, transistor, and a first resistor connected between said base and a voltage line, and also between the voltage line and said capacitor, the values of said first capacitor and first resistor determining said reference value and the arrangement being such that said first transistor is normally conductive due to the current flow in its base via said first resistor from the voltage line and that as the value of said input voltage at the input side of said first capacitor changes, due to increase in wheel deceleration, current through said first resistor is diverted from the base of said first transistor to the output side of said first capacitor until, when said reference value has been exceeded, so much of the current has been diverted that said first transistor is rendered nonconductive to cause a second, normally nonconductive, transistor to be rendered conductive to provide an output signal from the circuit at an output connection thereof.
Claim 3
Dependent Claim
49 words
The signal processing circuit of claim 1, wherein said processing circuit is arranged not to respond when said instantaneous value of the signal waveform exceeds said reference value until such value persists for longer than a predetermined period or varies in a sense denoting increasing deceleration over such period.
Claim 4
Dependent Claim
64 words
The signal processing circuit as claimed in claim 1, wherein said first transistor has its emitter connected to a base of a third transistor which is also normally conductive and is rendered nonconductive when said first transistor is rendered nonconductive, said second transistor having its base connected to a collector of said third transistor and being rendered conductive whEn the latter is rendered nonconductive.
Claim 5
Dependent Claim
33 words
The signal processing circuit as claimed in claim 3, wherein said second transistor is connected as an emitter follower transistor so as to provide the output signal from the circuit at its emitter.
Claim 6
Dependent Claim
58 words
The signal processing circuit as claimed in claim 3, wherein current through said first resistor is normally about 10 times the current needed to maintain said first and third transistors conductive, so that the predetermined value of wheel deceleration at which said second transistor becomes conductive is virtually independent of the gains of said first and third transistors.
Claim 7
Dependent Claim
90 words
The signal processing circuit as claimed in claim 1, further comprising a second resistor feeding the base of said first transistor, the value of said second resistor being so chosen that the voltage drop across it due to the current flow through it into the base of said first transistor determines a fixed amount of decrease in wheel speed by more than which a wheel is required to decrease its speed at a rate in excess of said predetermined value of wheel deceleration before said first transistor is rendered nonconductive.
Claim 8
Dependent Claim
18 words
The signal processing circuit as claimed in claim 1, wherein said voltage line is a stabilized voltage line.
Claim 9
Dependent Claim
59 words
The signal processing circuit as claimed in claim 1, wherein said first transistor is rendered conductive, after being rendered nonconductive, when the input voltage at the input side of said first capacitor next assumes the value indicative of said predetermined value of wheel deceleration whereby the output signal from the circuit is terminated when a second criterion is satisfied.
Claim 10
Dependent Claim
124 words
the signal processing circuit as claimed in claim 1, further comprising additional transistor means connected in parallel with said first transistor, said additional transistor means being normally nonconductive and being rendered partially conductive when said second transistor is rendered conductive, but not sufficiently so to render said second transistor nonconductive, the arrangement being such that said additional transistor means is rendered fully conductive to render said second transistor nonconductive when the input voltage at the input side of said first capacitor next assumes a value indicative of the start of wheel acceleration, or has exceeded a predetermined value, whereby the output signal from the circuit is terminated when a wheel starts to accelerate or exceeds a predetermined acceleration following initiation of an anti-lock action.
Claim 11
Dependent Claim
101 words
The signal processing circuit as claimed in claim 9, further comprising a potential divider connected in the emitter circuit of said second transistor to provide a bias current causing said transistor means to become partially conductive when said second transistor is rendered conductive, and a connection, including a capacitor, between the input side of said first capacitor and a base circuit of said additional transistor means, the latter being rendered fully conductive to render said second transistor nonconductive in response to the application to its base via said connection of input voltage, of a value indicative that wheel acceleration has started.
Claim 12
Dependent Claim
54 words
the signal processing circuit as claimed in claim 10, further comprising a bias resistor connected in the base circuit of said additional transistor means and modifying the response thereof, inaccordance with its value, such that said additional transistor means is rendered fully conductive to a value of input voltage indicative of a predetermined acceleration.
Claim 13
Dependent Claim
30 words
The signal processing circuit as claimed in claim 9, further comprising an emitter follower transistor through which said input voltage is applied to the input side of said first capacitor.
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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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |