Patent US4902565A successfully refreshed from Google Patents.
Patent US3866587A successfully refreshed from Google Patents.
US3866587A
Expired / Lapsed
US
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Automotive fuel heating control system
Assignee: Robert Bosch GmbH
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Filing: 1973-04-02
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Granted: 1975-02-18
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Expires: 1993-04-02
Abstract
Abstract To provide for predetermined heating of fuel applied to an automotive internal combustion engine, in spite of widely varying supply voltages, a heating resistance is connected, together with a reference resistance, in a bridge circuit which is connected across the power supply; the measuring diagonal of the bridge is connected to an operational amplifier, the output of which controls a variable resistance, such as a transistor, connected in series with the heating resistance to maintain current flow through the heating resistance at a uniform level.
Inventors
- 👤 Heinrich Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:09
CPC Classifications
F; F02; F02M; F02M31/00; F02M31/02; F02M31/12; F02M31/125; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
176 words
Automotive fuel heating control system, to control the heating effort of heating resistors (1, 2, 3, 11) located in the path of fuel flow to the internal combustion engine, comprising at least one heating and heat sensing resistor (11) exposed to the fuel to be heated; a reference resistance element (12); an operational amplifier (16); and two connecting resistors (13, 14), the reference resistance and the heating resistor being connected in one branch of a bridge circuit, the connecting resistors forming the other branch thereof, the operational amplifier being connected to the diagonal formed by the common junction of the reference resistance (12) and the heating and sensing resistor element (11) to sense unbalance of the bridge and to provide a resulting output signal; means (4, 8) providing a supply voltage; and means (15, 19) connected to and responsive to the output signal of the operational amplifier (16) to control the voltage being supplied from the voltage supply means to the bridge circuit, and hence the voltage applied to the heating and sensing resistor element (11).
Claim 2
Dependent Claim
176 words
Automotive fuel heating control system, to control the heating effort of heating resistors (1, 2, 3, 11) located in the path of fuel flow to the internal combustion engine, comprising at least one heating and heat sensing resistor (11) exposed to the fuel to be heated; a reference resistance element (12); an operational amplifier (16); and two connecting resistors (13, 14), the reference resistance and the heating resistor being connected in one branch of a bridge circuit, the connecting resistors forming the other branch thereof, the operational amplifier being connected to the diagonal formed by the common junction of the reference resistance (12) and the heating and sensing resistor element (11) to sense unbalance of the bridge and to provide a resulting output signal; means (4, 8) providing a supply voltage; and means (15, 19) connected to and responsive to the output signal of the operational amplifier (16) to control the voltage being supplied from the voltage supply means to the bridge circuit, and hence the voltage applied to the heating and sensing resistor element (11).
Claim 3
Dependent Claim
80 words
System according to claim 1, wherein the internal combustion engine has a throttle control; the system further comprises a differentiating network (23, 25) connected to sense change in position of the throttle control and providing an output signal to the voltage supply control means (15, 19) to modify the control effect thereof and provide rapid increase in supply voltage to the heating and sensing resistor element (11) upon sudden change in throttle position in direction of opening of the throttle.
Claim 4
Dependent Claim
48 words
System according to claim 2, wherein the differentiating network comprises a capacitor (23) and a potentiometer (25) having its slider electrically connected to the capacitor and its terminals connected across the supply voltage source, and its slider mechanically connected to the throttle control of the internal combustion engine.
Claim 5
Dependent Claim
25 words
System according to claim 1, wherein the voltage supply control means connected to the output of the operational amplifier (16) comprises an amplifier (15, 19).
Claim 6
Dependent Claim
74 words
System according to claim 4, wherein the amplifier comprises a first transistor (19) having its control electrode connected to the output of the operational amplifier (16); and a second transistor (15) having its control electrode connected to the output electrode of the first transistor, the second transistor having its emitter-collector path connected in series between the heating and sensing resistor element (11) in the bridge circuit and the source of supply voltage (4, 8).
Claim 7
Dependent Claim
20 words
System according to claim 1, further comprising an R/C network (21, 22) in the feedback path of the operational amplifier.
Claim 8
Dependent Claim
118 words
System according to claim 1, further comprising means (9, 10) sensing the voltage being supplied to the bridge circuit and hence to the heating resistance, under control of said voltage supply control means; at least one additional heating resistor (1, 2, 3) and a current supply control means (5, 6, 7) in series with each respective resistor, the series circuits formed of the current supply control means and the heating resistor being connected across the voltage source; and a connection from said voltage sensing means (9, 10) to the control terminal of the current supply control means (5, 6, 7) to control current flow through said series connection and hence through the additional heating resistors (1, 2, 3).
Claim 9
Dependent Claim
31 words
System according to claim 7, wherein the current supply control means comprises a transistor (5, 6, 7), each, the bases of the transistor, or transistors being controlled by said sensing means.
Claim 10
Dependent Claim
55 words
System according to claim 7, wherein said sensing means comprises a transistor (9) having its base connected to the junction of the heating and sensing resistor element (11) and the reference resistance 12, and its emitter-collector path connected across the supply voltage, The sensed output being taken from one of said emitter or collector terminals.
Claim 11
Dependent Claim
52 words
System according to claim 9, wherein the emitter-collector path of the sensing means transistor (9) is connected to the supply voltage source through a resistor (10); the junction of the resistor and the respective transistor electrode being connected to the base, or bases, of the additional transistor, or transistors (5, 6, 7).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |