GB1597210A - Apparatus for switching-off a direction indicator in a motor vehicle after cornering - Google Patents
Apparatus for switching-off a direction indicator in a motor vehicle after cornering Download PDFInfo
- Publication number
- GB1597210A GB1597210A GB16435/78A GB1643578A GB1597210A GB 1597210 A GB1597210 A GB 1597210A GB 16435/78 A GB16435/78 A GB 16435/78A GB 1643578 A GB1643578 A GB 1643578A GB 1597210 A GB1597210 A GB 1597210A
- Authority
- GB
- United Kingdom
- Prior art keywords
- output
- rotary direction
- discriminator
- switching
- threshold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
- B60Q1/00—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor
- B60Q1/26—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic
- B60Q1/34—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic for indicating change of drive direction
- B60Q1/40—Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor the devices being primarily intended to indicate the vehicle, or parts thereof, or to give signals, to other traffic for indicating change of drive direction having mechanical, electric or electronic automatic return to inoperative position
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Lighting Device Outwards From Vehicle And Optical Signal (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO APPARATUS FOR
SWITCHING-OFF A DIRECTION INDICATOR IN A MOTOR
VEHICLE AFTER CORNERING
(71) We, ROBERT BOSCH GMBH, a
German company of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The present invention relates to apparatus for switching-off a direction indicator in a motor vehicle after cornering.
According to the present invention there is provided apparatus for switching-off a direction indicator of a motor vehicle after cornering, in which two magnetic-fieldcontrolled sensors, which are disposed in fixed positions relatively to the vehicle steering column, are associated with at least one magnet on the steering column such that, for switching-off an actuated direction indicator, the sensors are operable successively upon rotation of the vehicle steering column back to or towards its normal or straight ahead position after cornering, the sequence of operation of the sensors being dependent on the direction of such rotation of the steering column, each sensor being connected between an operating voltage and earth, and in which a respective resistance-capacitance circuit in a rotary direction discriminator is connected between each sensor and an associated output, and a respective rectifier element reverse biassed by the operating voltage is connected between each sensor and the respective nonassociated output.
The term "magnetic-field-controlled sensor" as used in this specification and in the claiming clauses thereof is to be understood as meaning a circuit element which provides a change in output signal in response to a change in an applied magnetic field. Such a circuit element can be for example a reed switch, a Hall generator, a magnetoresistor.
a magnetodiode, a threshold value switch.
One advantage of apparatus embodying the present invention, especially when using reed switches as sensors, is that interconnected terminals of the sensors can be connected to earth potential directly at the place of installation without these terminals requiring a lead to the rest of the electron circuit. For triggering electronic circuit elements, particularly binary operating circuit elements, contacts of such reed switches can be connected in series with high-resistance series resistors and thereby are subjected to scarcely any power load, thereby promoting reliable switching behaviour and great durability. Furthermore, apparatus embodying the present invention does not require for each sensor, that is to say, for each channel of the rotary direction discriminator, two timing members adjusted to differing time constants for the purpose of triggering or blocking a transistor.Instead of this, the basic operation of apparatus embodying the present invention does not require active switching elements and only requires one timing circuit for each channel, namely a timing circuit used as a differentiating circuit, with an associated rectifier element which in practice, is an inexpensive commercially available diode.
Preferably an inverter is connected to the input of each resistance-capacitance circuit.
This addition to the circuit has the advantage of greater freedom from interference owing to the response threshold, determined by type, of an inverter of this type, and at the same time the steepness of the switching pulses is perceptibly improved.
Furthermore, such inverter prevents the producton of an output pulse when the steering wheel is turned from its normal position to commence cornering. If the output signals of the rotary direction discriminator are to be further processed with logic corresponding to the polarity of the operating voltage, this inverter at the same time has the further advantage of establishing, in this connection, coincidence between the polarities at the input and the output of the rotary direction discriminator.
Several inverters in the form of NOR gates or NAND gates can be combined in one housing, so that each individual, freely connectible inverter constitutes, from the viewpoint of the cost of material, a more advantageous solution than the use of an individual switching transistor, quite apart from the additional cost of wiring an individual transistor of this type.
Since the output signals of the rotary direction discriminator are differentiated voltage peaks of the resistance-capacitance circuits, it is advantageous to connect potential-controlled threshold stages to the output of the rotary direction discriminator in order to make defined binary switching states available in the further switching arrangement of the direction indicator. When the input stages of this further circuit of the direction indicator do not have the characteristic of potential-controlled threshold stages of this type owing to the characteristics of the components, it is sufficient to connect each output of the rotary direction discriminator to a gate of the COS-MOS type which, as is well known, has a pronounced response threshold which can be influenced by a voltage divider.
The invention will be further disclosed by way of example, with reference to the accompanying drawings in which a preferred embodiment of the invention is illustrated, and in which:
Figure 1 is a diagrammatic plan view of a steering wheel having a magnet mounted on its steering column and associated magneticfield-controlled sensors in the form of reed relays,
Figure 2 is a diagrammatic side elevation of the arrangement of Figure 1;
Figure 3 is a circuit diagram of an embodiment of the present invention having a rotary direction discriminator, and
Figure 4 shows two graphs for explaining the action of the rotary direction discriminator of Figure 3.
A preferably strip-shaped magnet 3 is secured, by for example an adhesive, to a motor vehicle steering column 2, provided with a steering wheel 1, which magnet extends over a circumferential angle a of, for example, approximately 45". The magnet 3 is magnetized in a horse-shoe pattern with poles extending in a radial direction so that the steel steering column 2 does not cause a magnetic short circuit. Two magnetic-field-controlled sensors K1 and K2 are mounted in front of the poles of the magnet 3 at a short dstance therefrom on, for example, a steering column lining 4, and, when the steering column 2 is in its normal position for straight ahead travel of the motor vehicle, are located within the circumferential angle a shown in Figure 1.
Thus, when the steering wheel 1 is is a position for straight ahead travel, the two sensors K1 and K2 are located in the magnetic field of the magnet 3, and the sensor contacts, which are preferably reed switch contacts, are closed.
As is shown in detail in Figure 3, one terminal of each sensor K1 and K2 is connected to earth potential which is available in the form of a part of the chassis of the motor vehicle at the location at which the sensors are mounted, without requiring longer connection leads to electronic subassemblies at another location on the motor vehicle. The other terminals of the contacts of each respective sensor K1 and K2 are connected to an operating voltage VBatt by way of respective series resistors Rv and
R'v, that is, in the illustrated embodiment, to the positive voltage of the battery of the motor vehicle.The series resistors Rv, R'v may be arranged separately in the course of the wiring accrding to the local conditions when using a device in accordance with the invention, or, as is shown in Figure 3, they may be component parts of a rotary direction discriminator 7 connected to the contacts of the sensors K1 and K2 by way of inputs 5 and 6 respectively.
In the illustrated preferred embodiment the input 5 is connected by way of a lead 8 to an inverter 79 whose output is connected to a resistance-capacitance circuit 80 (hereinafter referred to as an RC circuit) wired as a differentiating circuit. The output of the RC circuit 80 is connected to output 11 of the rotary direction discriminator 7 which is connected by way of a rectifier element, in the form of a diode D, to that input 6 of the rotary direction discriminator 7 which is associated with the other sensor K2, the diode D being connected such that it is reverse biassed by the operating voltage VBatt. A second channel which extends between the input 6 and output 12 of the rotary direction discriminator 7, and which is associated with the second sensor K2, is constructed in the same manner with the rectifier element. in the form of the diode
D'. mirror-symmetrically cross-coupled from the output 12 to the input 5. Therefore, the previously mentioned components provided within the rotary direction discriminator 7 have the same reference numer als, supplemented by an apostrophe in each case.
A direction indicator 13 is connected to the output of the rotary direction discriminator 7. The direction indicator essentially comprises two flip-flops- 14 and 15, a flasher unit 16, and flasher lights 17 and 18 for the respective directions of travel.
An input 19 of the flip-flop 14 and an input 20 of the flip-flop 15 are connected to the outputs 12 and 11 respectively of the rotary direction discriminator 7. The other inputs 21 and 22 of the respective flip-flops 14 and 15 are connectible to signal potential by way of respective push-button switches 23 and 24 Each flip-flop 14 and 15 is connected to a source of voltage. The push-button switches 23 and 24 can be in the form of capacitive sensors and they serve to initiate "flash right" and "flash left" respectively.
The outputs 25 and 26 of the respective flip-flops 14 and 15 are connected to the corresponding inputs 27 and 28 of the flasher unit 16 whose associated outputs 29 and 30 are connected to earth by way of the flasher lamps 17 and 18 respectively.
The mode of operation of the previously described device for "resetting the flasher" after travelling round a right-hand corner will now be described:
When travelling straight ahead, the contacts of the two sensors K1 and K2 are closed, that is, the inputs of the inverters 79, 79' are connected to earth potential i.e.
carry a logic 0 signal. Consequently, their outputs carry a logic 1 signal, and the outputs 11 and 12 of the rotary direction discriminator 7 carry earth potential when in the steady state, since the charging current for the capacitors C and C' of the respective
RC circuits 80, 80' has decayed. When the steering wheel 1 is turned to the right in accordance with the rotary direction arrow 31, the sensor K1 leaves the magnetic field of the magnet 3 first and its contacts are opened. Since the input of the inverter 79 now carried logic 1 potential, the capacitor
C is discharged, which, however, only leads at the output to a differential negative voltage charge which is not processed by the following switching arangement which is arranged for positive logic.Upon further rotation of the steering wheel 1 in the direction of the arrow 31, the contact of the second sensor K2 also finally opens and the capacitor C' in this channel is also discharged, and only a differential negative voltage pulse also appears at the output 12.
Thus, the two capacitors C,C' of the RC circuits 80, 80' are discharged when the steering wheel is in this turned position.
When the steering wheel 1 is returned to its normal or straight-ahead position after the motor vehicle has travelled round the corner, that is to say, when the steering wheel is turned to the left in the direction of the arrow 32, the second sensor K2 is the first to be affected by the magnetic field of the magnet 3 and its contacts are closed. The input of the inverter 79' of this second channel is thereby switched to logic 0 potential, so that a logic 1 signal appears at its output and, as a result of the charging current a position voltage momentarily appears across the resistor R'. This pulse appearing at the output 12 of the rotary direction discriminator 7 is shown in an ideally simplified form in the upper graph of
Figure 4.The time constant of the RC circuits 80,80' is chosen such that, with a normal rotational speed of the steering wheel 1, this positive voltage pulse, which is proportional to the recharging current has substantially decayed before the first sensor
K1 has also again entered the range of influence of the magnetic field of the magnet 3; otherwise, the output pulse would be automatically terminated upon the closing the contact of the first sensor K1. Since, in practice, a relatively long period of time elapses during the turning back of the steering wheel 1, the effective width of the output pulse can be predetermined within relatively wide limits by appropriate selection of the time constant of the RC circuits 80 and 80' in order to adapt the output pulse to the requirements of the following circuit in an optimum manner.
Since the input of the inverter 79 is also switched to logic 0 potential, charging of the capacitor C now takes place similarly in the channel of the rotary direction discriminator 7 associated with the first sensor Kl.
However, the voltage pulse previously described does not now appear at the output 11, since the diode D is connected in parallel with the charging resistor R by the contacts of the second sensor K2 which had previously entered the range of influence of the magnet 3 being already closed. Consequently, the charging current for the capacitor C essentially does not flow through the charging resistor R, but flows through the diode
D which is forward biased for this purpose, so that, during this charging operation, only a small momentary voltage rise (shown by a broken line in the upper graph of Figure 4), determined by the threshold voltage of the diode D, appears at the output 11 and, owing to its limited amplitude, is insufficient to trigger any switching operation in the direction indicator 13 connected on the output side.The value of 0.7,volts is given for this small voltage rise in Figure 4 since, in this instance, the rectifier elements are normally in the form of silicon diodes which have a pronounced threshold voltage lying at 0.7 volts.
Thus, a considerable positive voltage pulse has appeared only at the output 12 of the rotary direction discriminator 7 upon turning the steering wheel 1 from the right-hand lock back into the straight-ahead position or normal position. It may be advantageous to connect a potentialcontrolled switching or threshold stage to each output 11, 12 of the rotary direction discriminator 7 in order to have defined binary signals available for triggering the direction indicator 13 connected to the output of the rotary direction discriminator 7.Referring to Figure 3, threshold stages of this type are in the form of gates 81, 81', which are preferably of the COS-MOS type, that is, they have a defined response threshold of approximately 50% of the operating voltage VBatt. In the event that non-inverting gates 81, 81' are provided in this instance, the output signal shown in the lower graph of Figure 4 appears at the outputs of the said gates upon the appearance of a positive voltage pulse which exceeds the response threshold of the gates (upper graph of Figure 4).
When the push button 23 has been actuated and the flip-flop 14 has been set by a signal applied to its SET input 21, before the steering wheel 10 commences to be turned to the right, the flasher unit 16 is triggered by way of an output 25 of the flip-flop 14 and thus the flasher lights 17 are operated.
When, upon turning back the steering wheel 1 to the left, the previously described positive voltage pulse appears at the output 12 of the rotary direction discriminator 7 or at the output of the gate 81' connected on the output side and operating as a threshold value switch, the flip-flop 14 is reset by way of its RESET input 19, and the operation of the flasher unit 16, and thus of the flasher lights 17, is terminated. Thus it is ensured that, whenever the steering wheel 1 is turned back to the left, the only signal to appear at one of the outputs 11, 12 of the rotary direction discriminator 7 is a signal which cancels a previously initiated "flashing right" operation.
Similarly, as described above with reference to Figure 4, a positive voltage pulse appears at the other output 11 of the rotary direction discriminator 7 when, and only when, the steering wheel 1 is moved to the right back from a left lock position into the straight-ahead position, as is indicated by the rotary direction arrow 31 in Figure 3. If "flashing left" had previously been initiated by means of a push-button 24 applying a signal to its SET input 22, the associated flip-flop 15 is reset to its initial state by way of its RESET input 20 connected to the output 11.
The mode of operation of the rotary direction discriminator 7 does not change when sensors Kl and K2 of a different type, such as Hall generators, magnet resistors, magnet diodes or threshold value switches, are used instead of reed switches, it only being necessary, perhaps, to modify the wiring with series resistors Rv, Rv'. It is also of no importance to the essential feature of the invention whether a single magnet or a plurality of magnets are provided, if it is only ensured that the switching sequence of the sensors K1 and K2 leads to the reversal of the changes on the capacitors C, C' in the
RC circuits 80,80' in the manner previously described.If the direction indicator 13 is constructed with switching elements arranged for negative logic and whose inputs require a logic 0 signal for resetting the operation of the flasher, gates 81, 81' having inverting outputs (NOR or NAND gates) can be connected as potential-controlled threshold stages to the outputs 11, 12 of the rotary direction discriminator 7 in a simple manner.
WHAT WE CLAIM IS:
1. Apparatus for switching-off a direction indicator of a motor vehicle after cornering, in which two magnetic-fieldcontrolled sensors, which are disposed in fixed positions relatively to the vehicle steering column, are associated with at least one magnet on the steering column such that, for switching-off an actuated direction indicator, the sensors are operable successively upon rotation of the vehicle steering column back to or towards its normal or straight ahead position after cornering, the sequence of operation of the sensors being dependent on the direction of such rotation of the steering column, each sensor being connected between an operating voltage and earth, and is in which a respective resistance-capacitance circuit in a rotary direction discriminator is connected between each sensor and an associated output, and a respective rectifier element reverse biassed by the operating voltage is connected between each sensor and the respective non-associated output.
2. Apparatus as claimed in claim 1, in which an inverter is conncted to the input of each resistance-capacitance circuit.
3. Apparatus as claimed in claim 1 or 2, in which each rectifier element is a diode.
4. Apparatus as claimed in any of the preceding claims, in which a potentialcontrolled threshold stage is connected - to each output of the rotary direction discriminator.
5. Apparatus as claimed in claim 4, in which each threshold stage is a gate of the
COS-MOS type.
6. Apparatus as claimed in claim 4 or 5, in which each threshold stage is set to respond at approximately half the peak voltage of the voltage drop of the charging current in the respective resistancecapacitance circuit.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (7)
1. Apparatus for switching-off a direction indicator of a motor vehicle after cornering, in which two magnetic-fieldcontrolled sensors, which are disposed in fixed positions relatively to the vehicle steering column, are associated with at least one magnet on the steering column such that, for switching-off an actuated direction indicator, the sensors are operable successively upon rotation of the vehicle steering column back to or towards its normal or straight ahead position after cornering, the sequence of operation of the sensors being dependent on the direction of such rotation of the steering column, each sensor being connected between an operating voltage and earth, and is in which a respective resistance-capacitance circuit in a rotary direction discriminator is connected between each sensor and an associated output, and a respective rectifier element reverse biassed by the operating voltage is connected between each sensor and the respective non-associated output.
2. Apparatus as claimed in claim 1, in which an inverter is conncted to the input of each resistance-capacitance circuit.
3. Apparatus as claimed in claim 1 or 2, in which each rectifier element is a diode.
4. Apparatus as claimed in any of the preceding claims, in which a potentialcontrolled threshold stage is connected - to each output of the rotary direction discriminator.
5. Apparatus as claimed in claim 4, in which each threshold stage is a gate of the
COS-MOS type.
6. Apparatus as claimed in claim 4 or 5, in which each threshold stage is set to respond at approximately half the peak voltage of the voltage drop of the charging current in the respective resistancecapacitance circuit.
7. Apparatus for switching off a direc
tion indicator of a motor vehicle after cornering, constructed and arranged and adapted to operate substantially as hereinbefore particularly described with reference to and as illustrated in the accompanying
drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2725805A DE2725805C2 (en) | 1977-06-08 | 1977-06-08 | Device for switching off a direction indicator in a motor vehicle after cornering |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1597210A true GB1597210A (en) | 1981-09-03 |
Family
ID=6011011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB16435/78A Expired GB1597210A (en) | 1977-06-08 | 1978-04-26 | Apparatus for switching-off a direction indicator in a motor vehicle after cornering |
Country Status (5)
| Country | Link |
|---|---|
| DE (1) | DE2725805C2 (en) |
| FR (1) | FR2393700A1 (en) |
| GB (1) | GB1597210A (en) |
| IT (1) | IT1096546B (en) |
| SE (1) | SE419621B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2129218A (en) * | 1982-09-29 | 1984-05-10 | Electronic Components Ltd | Direction indicator cancellation device |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54144193A (en) * | 1978-05-01 | 1979-11-10 | Tokai Rika Co Ltd | Automotive direction indicator |
| DE2913008C3 (en) * | 1979-03-31 | 1984-10-25 | Fa. Leopold Kostal, 5880 Lüdenscheid | Device for the automatic resetting of a direction indicator in motor vehicles |
| FR2539360B1 (en) * | 1983-01-14 | 1987-09-18 | Dav Ind | DEVICE FOR DISCONNECTING A DIRECTION INDICATOR OF A MOTOR VEHICLE |
| DE10037760A1 (en) | 2000-08-03 | 2002-02-14 | Eaton Corp | Reset device for a switch of a motor vehicle |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2460918C2 (en) * | 1974-12-21 | 1983-06-01 | Robert Bosch Gmbh, 7000 Stuttgart | Device for switching off a direction indicator in a motor vehicle after cornering |
| DE2608865C2 (en) * | 1976-03-04 | 1984-03-01 | Robert Bosch Gmbh, 7000 Stuttgart | Device for switching off a direction indicator in a motor vehicle after cornering |
-
1977
- 1977-06-08 DE DE2725805A patent/DE2725805C2/en not_active Expired
-
1978
- 1978-04-26 GB GB16435/78A patent/GB1597210A/en not_active Expired
- 1978-04-28 FR FR787812833A patent/FR2393700A1/en active Granted
- 1978-05-29 SE SE7806135A patent/SE419621B/en unknown
- 1978-06-07 IT IT24312/78A patent/IT1096546B/en active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2129218A (en) * | 1982-09-29 | 1984-05-10 | Electronic Components Ltd | Direction indicator cancellation device |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2393700B1 (en) | 1983-12-09 |
| FR2393700A1 (en) | 1979-01-05 |
| DE2725805A1 (en) | 1978-12-14 |
| SE419621B (en) | 1981-08-17 |
| IT7824312A0 (en) | 1978-06-07 |
| DE2725805C2 (en) | 1984-02-23 |
| SE7806135L (en) | 1978-12-09 |
| IT1096546B (en) | 1985-08-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |