GB2177515A

GB2177515A - Warning lamp checking circuit

Info

Publication number: GB2177515A
Application number: GB08612536A
Authority: GB
Inventors: Tetuo Yamashita
Original assignee: Suzuki Motor Corp
Current assignee: Suzuki Motor Corp
Priority date: 1985-06-04
Filing date: 1986-05-22
Publication date: 1987-01-21
Also published as: DE3618722C2; GB2177515B; DE3618722A1; FR2582600B1; CA1261019A; JPH049228Y2; JPS61199439U; GB8612536D0; FR2582600A1

Abstract

In a warning lamp checking circuit for use in vehicles having at least one condition warning lamp (19, 22) which can be operative or inoperative, closing a main switch (4), a starter switch (5) and a clutch switch (6) causes the warning lamp to light for about one second if the lamp is operative irrespective of the state of a condition switch (21), thereby allowing the operability of the warning lamp to be checked each time the starter switch is closed. After one second the warning lamp lights only if the condition switch (21) is closed. As shown, a time switch (7) applies ground potential to a terminal (7c) for a period of about one second after application of the full battery potential to an input terminal (7a), but thereafter it applies the full battery potential instead. <IMAGE>

Description

SPECIFICATION Vehicle warning lamp checking circuit Field of the invention The present invention relates to a warning lamp checking circuit designed to determine the operabil- ityofa variety of warning lamps frequently used on vehicles. One such lamp is that which warns that a motorcycle kickstand is still set when the rider attempts to start the motorcycle.

Description ofthepriorart Vehicles, such as automobiles and motorcycles, are commonly provided with several kinds of warning lamps in addition to the kickstand warning lamp referred to above. These lamps are lighted to inform the operator of the vehicle of the existence of a state that is inappropriate for operation of the vehicle.

Since they are provided for informing some abnormality by lighting, these lamps are not lighted when devices to which the warning lamps are connected operate normally or when these devices are set artificially in appropriate conditions. However, if a condition responsive lamp remains unlit,there are two possibilities. The first possibility is that the condition is normal. The second possibility is that the lamp is inoperative. The lamp may be inoperative for a wide variety of reasons. It may be burned out. It may be unscrewed in its socket. It may be in a broken circuit.

Consequently, there is the possibility that an unlit inoperative lamp will convey misinformation tothe vehicle operator.

One ofthe prior art circuits used to solve the abovestated problem relies on the oil pressure lamp circuit.

The oil pressure lamp is lighted for only a brief period until the oil pressure rises afterthe main switch is turned on. This feature is utilized so that warning lamps responsiveto other conditions are lighted simultaneously with the oil pressure lamp. The use of such a circuit is confusing because two lamps respon sive to two quite differentconditions are lighted and extinguished simultaneously. It can be considered, in this relation,thata contactforchecking is provided at the main switch so as to check up the operability of a condition-responsive lamp when the main switch is operated. However, this requires a main switch of special specifications which increases manufacturing costs.

An object of the present invention is to provide a circuitfor checking the operability of warning lamps of vehicles in which the above-stated problems are solved.

Summary of the invention In orderto solve the aforesaid problems, the present invention uses a publicly-known timer-switch having two output terminals, each with a different output voltage profile. In one output terminal, the voltage is ground voltage for a certain time from the moment of impression of a voltage on the inputterminal and then increasestoinputvoltageafterthe passage of said time using also a construction in which abnormalitywarning lamps of various devices and a diode being forward in the direction from a power source to the output terminal of said timerswitch, are connected in series between said output terminal of the timer and the power source.

According to this circuit, the abnormality warning lamps are lighted only for a certain time after the start of an engine. Operability ofthe lamps is determined only bytheconfirmation ofthe lighting ofthese lamps, and thus reliability on normal functions can be put on the related devices when the lamps are not lighted.

Moreover, the aforesaid object can be attained only by providing an additional circuitwithoutanyremod- eling ofothercomponentssuchasthe main switch.

This makes it easy to manufacture the circuit of the present invention and also makes it possible to attach this circuit to existing vehicles.

Briefdescription ofthe drawings Figure 1 is a circuit diagram of an embodiment of the present invention; and Figure2 is a graph showing the change in voltage overtimeatan inputterminal 7a of atimer7; and Figure 3 is a graph showing the change in voltage overtime at an output terminal 7c ofthetimer-switch 7; and Figure 4 is a graph showing the change in voltage overtime at an output terminal 7b of the timer-switch.

Description ofthe preferred embodiment Since the present invention uses a timer-switch employed in a publicly-known decompression device, the whole of the decompression device is also disclosed in Figure 1 showing one embodiment of the present invention. This decompression device operate to lead the function of a device which temporarily reduces the pressure in a combustion chamber of an engine when the starter motor is operated.

A description will be made on the aforesaid decompression device priortothe description on the present invention. Numeral 1 denotes a battery (power source) which is mounted on a vehicle (not shown) and grounded (body-grounded, and so forth) on the negative pole side. The positive pole side of the battery 1 is connected to fuses 2 and 3. The other end of the fuse 2 is connected to a source terminal 7a of a timer-switch 7 through a series circuit composed of a main switch 4, a starter switch 5 and a clutch switch 6.

The timer-switch 7 has outputterminals 7b and 7c and a ground terminal 7d.Thevoltage atthe output terminal 7c is ground voltage, namely, zero for a certain time, e.g., for 1.0 seconds as shown in Figure 3. Time zero begins with the moment of impression of a constant voltage on the source terminal 7a as shown in Figure 2. Afterthe passage of this switching time, the voltage becomes equal to the input voltage.

As for the output terminal 7b, the i nput voltage is maintained for a certain time, e.g., for 0.5 seconds as shown in Figure 4. Time zero begins with the moment of impression of avoltage onthe sourceterminal 7a.

After the passage of said period of time, the voltage becomes zero.

A circuit for operating the decompression device including the aforesaid timer-switch 7 is constructed in the following way. The coil 9 of a relay8 is connected between the fuse 3 and the outputterminal 7b ofthe timer-switch 7. The normally-open contact 10 ofthe relay 8 and the coil 12 of a starter motor relay 11 are connected in series between the fuse 3 and the ground. The normally-open contact 13 ofthestarter motor relay 11 is connected between the battery 1 and a starter motor 14, one pole of which is grounded.

The starter motor is adapted to turn the main drive shaft of an internal combustion engine (not shown).

The coil 16 of a relay 15 is connected betweenthefuse 3 and the output terminal 7c of the timer-switch 7. The normally-open contact 17 of this relay 15and a de compression device 18 are connected in series be tween the fuse 3 and the ground.

The above-described circu it functions as follows.

When the main switch 4 is closed for starting an engine and then the starter switch 5 is closed for a prescribed time, a current from the battery 1 flows to the source terminal 7a of the timer-switch 7 through the clutch switch 6. The clutch switch 6 is closed when the clutch pedal (not shown) is depressed. Thereby, the timer-switch 7 starts a time-limiting operation.

When the source terminal 7a ofthetimer-switch 7 is inthisstate, a source voltage (e.g.,a voltage of 12 volts) given by the closure ofthe main switch 4takes placeattheoutputterminal 7b onlyfora definitetime (e.g., for 0.5 seconds) afterthe starter switch 5 is closed, as shown in Figure 4. Therefore, no current flows through the coil 9ofthe relay 8 during thistime, and consequently, the normally-open contact 10 re mains open. Thus, the starter motor 14 does not ro tate.

After 0.5 seconds, current flows through the coil 9 ofthe relay 8 and the starter motor 14 rotates. Mean while, current passes through the coil 16 of the relay 15, 0.5 seconds earlierthan said excitation, and it continues to a point in time 0.5 seconds later than the pointin time atwhich the startermotor 14startsto rotate. Consequently,thepressureinsidethecom- bustion chamber of the engine is lowered during this time, facilitating starting.

Next, a description will be made of the construction ofthe present invention in which the timer-switch 7 in the aforesaid circuit is used. In this construction, a kickstand lamp 19, as one example of warning lamps, and a diode 20 being forward in the direction from the power source side (the main switch 4 side) toward the outputterminal 7care connected in series between the node of the main switch 4 and the starter switch 5 and the output contact 7c ofthe timer-switch 7.

Moreover, a kickstand switch 21 is connected be tween the node of the kickstand lamp 19 and the diode 20 and the ground.

The kickstand switch 21 is closed whenever the kickstand 24 (see Figure 5) is away from the side ofthe vehicle whether drawn out completely to be set on the lateral side of the vehicle body for parking or held back incompletely. Accordingly, warning is required when said switch 21 is closed, and therefore, the kickstand lamp 19 is lighted by the circuit shown.

When the main switch 4 is closed for starting the engine, a current is caused to flow to the kickstand lamp 19, even with the kitckstand switch 21 opened, bythe output terminal 7cwhose potential is zero at that point in time. Consequently, the kickstand lamp 19 continuesfor1 .0 seconds in a mannersimilarto that of decompression device 18. By this lighting, operability of the kickstand lamp 19 is confirmed.

Referring now to Figure 5 there is shown a vehicle in the form of a motorcycle 22 having a kickstand 24 carried bytheframe 26. An engine 28 is also carried bytheframe26. As shown in Figure 5the kickstand 24 is in the down position. The switch 21 is,therefore, closed as shown in Figure 5. When the kickstand 24 is in the up position,the switch 21 would be open as shown in Figure 1.

The circuit ofthe present invention can be used with a wide variety of vehicles as long as they are powered by one or more internal combustion engines. Examples of vehicles include automobiles, trucks, locomotives, motorcycles and motortricycles.

The same object can be attained, in the present invention, by providing in parallel an open doorwarning lamp 22, a diode 23 and a switch 24, forinstance, in the same way as the circuit of the lamp 19, the diode 20 and the switch 21 provided between the intermediate point ofthe main switch 4 and the star- terswitch 5 and the output terminal 7c ofthetimer. By providing likewise in parallel a plurality ofwarning lamps which are lit in response to various functions of a vehicle, any inoperability of the warning lamps is automatically checked when the engine is started.

Claims

1. Avehiclewarning lamp checking circuitcomprising a timer-switch having a terminal whereby a voltage impressed from a starter switch of an engine connected to a power source is grounded for a certain timefromthemomentofimpressionofthevoltage,a warning lamp and a diode being forward in the direction from the power source side to said terminal which are connected in series between the intermediate point of said power source and the starter switch and the aforesaid terminal, and a second switch for detecting a defective state which is provided between the intermediate point of said warning lamp and the terminal and the ground.

2. A circuit of Claim 1, constructed by connecting in parallel a plurality of series circuits each of which comprises the aforesaid warning lamp and diode.

3. A motorcycle comprising: A. a frame; and B. a battery having a positive terminal and a negative terminal, wherein the negative terminal is grounded to the frame; and C. a kickstand carried by the frame; and D. a main switch in series with the positive terminal ofthe battery; and E. a starter switch in series with the main switch; and F. a timer-switch having an inputterminal in series with the starter switch; said timer-switch further comprising a time-delay output terminal whose output potential remains at zero for about one second after an increase in the potential atthe inputterminal ofthe timer-switch; and G. akickstand warning lamp capable of being both operative and inoperative and having an outputterminal and an input terminal; wherein the inputterminal is in series with the main switch; and H. a kickstand position switch carried by the frame wherein the kickstand position switch is in series with the output terminal ofthe kickstand warning lamp; said kickstand position switch being closed when the kickstand is away from the frame and being otherwise open; and I. a diode, one terminal of which is in series with the output terminal ofthe kickstand warning lamp; the otherterminal of which is in series with thetimedelay output terminal of the timer-switch; and wherebyclosing both the main switch and the starterswitch causesthe kickstand warning lamp to light for about one second if the kickstand warning lamp is operative irrespective ofthe position ofthe kickstand, thereby giving any operator ofthe motorcycle an opportunity to observe the operative nature of the kickstand warning lamp each time the starter switch is closed; and whereby after about one second the kickstand warning lamp lights if, and only if, the kickstand switch is closed thereby indicating that the kickstand is away from the frame.

4. Avehicle having a condition responsivewarning lamp designed to light in responseto an unsafe conditions; said vehicle comprising: A. a frame; and B. a battery having a positive terminal and a negative terminal, wherein the negative terminal is grounded to the frame; and C. a kickstand carried by the frame; and D. a main switch in series with the positive terminal of the battery; and E. a starter switch in series with the main switch; and F. a timer-switch having an inputterminal in series with the starter switch; said timer-switch further comprising a time-delay output terminal whose output potential remains at zero for about one second after an increase in the potential at the input terminal ofthe timer-switch; and G. acondition responsive warning lamp capable of being both operative and inoperative and having an output terminal and an input terminal; wherein the inputterminal isin series with the main switch; and H. a condition responsive position switch carried by theframewhereinthe kickstand position switch is in series with the output terminal of the condition re sponsivewarning lamp; said condition responsive position switch being closed when the condition is safe and being closed when the condition is unsafe; and I. a diode, one terminal of which is in series with the output terminal of the condition responsive warning lamp; theotherterminal of which is in series with the time-delay outputterminal ofthetimer-switch; and whereby closing both the main switch and the starter switch causes the condition responsive warning lamp to lightforaboutonesecond if the condition responsive warning lamp is operative whetherthe condition is safe or unsafe, thereby giving any operatorofthevehicleanopportunitytoobservetheoperative nature ofthe condition responsive warning lamp eachtimethe starterswitch is closed; and whereby after about one second the condition re sponsivewarning lamp lights if, and only if, the condition responsive switch is closed thereby indicating that the condition is unsafe.

5. Avehiclewarning light checking circuit as claimed in claim 1 and substantially as described with reference to and as illustrated in the accompanying drawings.

6. Each and every novel feature herein setforth taken either separately or in combination.