JPS63170144A - Flasher device - Google Patents

Abstract

PURPOSE:To make no current detecting resistance required, by enabling the disconnection of a lamp filament to be determine by variation in speed during the operation of a driving switch for the condensed voltage of a capacitor connected to a series circuit comprising a plural number of lamps such as a direction indicator lamp, and a starter switch. CONSTITUTION:Turning on of a starter switch 2 causes the output voltage of a voltage regulator 13 to flow to an earth, for instance, via direction indicator lamps 1L. Then, a switch operation detection circuit 14 is caused to operate to activate a oscillator 15, and an oscillation signal therefrom causes a transistor 5 controlling a relay switch 4 via a divider 16 to turn on and off, flashing the direction indicator lamps. In this case, the disconnection of a filament in one of the direction indicator lamps 1L results in a slower speed of reduction in the terminal voltage of a condenser 21 compared with that before disconnection and a greater counted value by a count 27 than a reference value, and thereby a change-over switch 17 is changed over via a comparison circuit 30. Hence, the flashing frequency of the lamps 1L will be greater and the disconnection will be alarmed.

Description

[Detailed description of the invention] Technical field The present invention relates to a flasher device.

BACKGROUND TECHNOLOGY The first example of a conventional flasher device is an in-vehicle direction indicating device.
As shown in the figure. In this device, two left and right direction indicator lamps IL and IR are provided, and are selectively selected by operating a flasher activation switch 2. The activation switch 2 has an intermediate position in which it is in a non-selected state, and direction indicator lamps IL and IR are connected to its fixed contacts. A power supply voltage vB is supplied to the movable contact of the starting switch 2 via a current detection resistor 3 and a relay switch 4. Relay switch 4 is turned on when relay coil 5 is excited. A power supply voltage VB is supplied to one end of the relay coil 5, and the other end is grounded via the collector and emitter of the switching transistor 6. An oscillator 8 is connected to the base of the transistor 6 via a resistor 7. On the other hand, the voltage across the current detection resistor 3 is supplied to a discrimination circuit 9 consisting of a comparator. The discrimination circuit 9 outputs two direction indicating blocks IL from the voltage across the current detection resistor 3.
%IR filament breakage is determined and the determination result is supplied to the oscillator 8. When the start switch 2 is turned on, the oscillator 8 starts an oscillation operation by, for example, a switch linked thereto and generates an oscillation signal to the transistor 6, and the oscillation frequency changes according to the determination result of the determination circuit 9. It has become.

In this configuration, when the starting switch 2 is operated and turned on from the intermediate position to one of the fixed contacts, the oscillator 8 starts oscillating, and the oscillation signal is supplied to the base of the transistor 6 via the resistor 7. be done. As a result, the transistor 6 starts to turn on and off, and the voltage VS is intermittently applied to the relay coil 5 at the oscillation frequency of the oscillator 8.

Therefore, since the relay switch 4 turns on and off, the voltage VB
The current flows intermittently to ground through the resistor 3, relay switch 4, starting switch 2, direction indicator lamp IL% or IR, and causes the direction indicator lamp IL1 or IR to blink. At this time, the current flowing through the direction indicator lamp IL or IR is detected by the resistor 3 as a voltage across both ends. When the terminal voltage of the resistor 3 drops below a predetermined voltage when the transistor 6 is turned on, the discrimination circuit 9 inverts the output from a low level to a high level. The oscillator 8 changes its oscillation frequency in response to this high level output. For example, if the filament of one lamp breaks when two direction indicator lamps IL are flashing, the resistor 3, relay switch 4,
Since the current flowing through the series circuit of the starting switch 2 and the other direction indicator lamp IL decreases to about 172, the voltage across the resistor 3 drops below a predetermined voltage, and the oscillation frequency of the oscillator 8 increases. Therefore, the other direction indicator lamp IL
blinks faster, informing the driver that the filament of one of the direction indicator lamps IL is broken.

In addition, such a flasher device is, for example,
It is disclosed in Japanese Patent No. 7-50690.

However, in such a flasher device, it is necessary to provide a current detection resistor in the current path of the direction indicator lamp, and if this current detection resistor has a large value, the illuminance of the direction indicator lamp will be reduced, resulting in poor power consumption efficiency. There was a problem with that.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a flasher device that can obtain good power consumption efficiency and reliably change the blinking frequency of at least two lamps when the filament of one lamp is broken. It is to be.

The flasher device of the present invention includes a plurality of lamps, a capacitor connected to a series circuit consisting of a starting switch, and a drive switch such as a relay switch that turns on and off and responds to the rate of change in the voltage stored in the capacitor when the drive switch is activated. The device is characterized in that it has a driving means for changing the on/off frequency of the driving switch.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 and 3.

In the vehicle-mounted direction indicating flasher device which is an embodiment of the present invention shown in FIG. 2, the same parts as the device shown in FIG. A power supply voltage Ve (for example, 12V) is applied to the series circuit of the lamps IL%IR. A voltage Vc is applied to the connection point between the relay switch 4 and the starting switch 2.
e (for example, 5V) is a resistor 11 and a diode 12
is fed through in the forward direction. Voltage Vcc is power supply voltage V
It is obtained by making B constant voltage by the voltage regulator 13. A switch operation detection circuit 14 is connected to the connection point between the resistor 11 and the anode of the diode 12 in order to detect the ON operation of the starting switch 2. The detection circuit 14 is composed of a flip-flop, a counter, etc., and generates a high level output in response to the fall of the input signal, and returns to the low level output when this state continues for a predetermined time or more after the input signal rises. An oscillator 15 is connected to the output of the detection circuit 14. The oscillator 15 performs oscillation only while the high level output of the detection circuit 14 is supplied.

A frequency divider 16 is connected to the oscillator 15, and the output signal of the oscillator 15 and the output signal of the frequency divider 16 are alternatively selected by a changeover switch 17. A movable contact at the selection output end of the changeover switch 17 is connected to the base of the transistor 6 via a resistor 7.

Further, a capacitor 21 is connected in parallel to the series circuit of the starting switch 2 and the direction indicator lamp IL%IR, and the voltage across the capacitor 21 is supplied to a voltage comparison circuit 22. The comparator circuit 22 is supplied with a voltage divided by the resistors 23 and 24 of the voltage Vs as a reference voltage Vr. An AND circuit 25 is connected to the output of the comparison circuit 22, and the AND circuit 25 calculates the logical product of the output signal of the comparison circuit 22 and the inverted signal of the selection output signal of the changeover switch 17 by the inverter 26.

A digital counter 27 is connected to the output of the AND circuit 25, and the counter 27 counts clock pulses output from the clock generation circuit 28 in accordance with the output signal of the AND circuit 25.

The count value of the counter 27 is supplied to a digital comparison circuit 30 via a latch circuit 29, and is compared with a reference value output from a memory 31 such as a ROM.

The latch circuit 29 reads the count value of the counter 27 in response to the fall of the output signal of the AND circuit 25, and holds and outputs the count value. The output signal of the comparator circuit 30 is transferred to the selector switch 1.
7 and controls the selection operation of the selector switch 17.

Although not shown, a circuit is provided between both terminals of the relay coil 5 to absorb back electromotive force generated between both terminals of the relay coil 5 when the transistor 6 is turned off.

In the flasher device according to the present invention having such a configuration,
As shown in FIG. 3(a), at time t1, the start switch 2
is operated to turn on one fixed contact from the intermediate position, current flows from the output of the voltage regulator 13 to ground via the resistor 11, diode 12, start switch 2, and direction indicator lamp IL% or IR. . Therefore, the input voltage of the switch operation detection circuit 14 is as shown in FIG.
), the voltage Vee decreases to a predetermined voltage or less. When the switch operation detection circuit 14 detects this falling voltage, it supplies a high level output to the oscillator 15 indicating that the starting switch 2 is turned on. As a result, the oscillator 15 starts its oscillation operation and generates a first oscillation signal (for example, 170 cp) as shown in FIG. 3(c). This first oscillation signal is frequency-divided by the frequency divider 16 to become a second oscillation signal (for example, 85 cp) as shown in FIG. 3(d). When the output level of the comparison circuit 30 is low level, that is, the direction indicator lamp I L selected by the start switch 2
When no filament breakage occurs in s or IR, the selector switch 17 relays the second oscillation signal output from the frequency divider 16 to the base of the transistor 6 via the resistor 7, as shown in FIG. 3(e). do. Transistor 6 is the second
The current is intermittently supplied to the relay coil 5 by turning on and off according to the oscillation signal. Therefore, since the relay switch 4 is turned on and off, the current due to the voltage VB is intermittently applied to the relay switch 4, the starting switch 2, and the direction indicator lamp LL% or IR.
It flows to ground through the circuit, causing the direction indicator lamp IL1 or IR to blink.

As shown in FIG. 3(f), the terminal voltage of the capacitor 21 becomes equal to the voltage Ve when the relay switch 4 is on.
When the relay switch 4 is turned off, the accumulated charge flows as a current through the starting switch 2 and then through the direction indicator lamp IL or IR and is discharged, so that the electric charge gradually decreases. When the terminal voltage of the capacitor 21 is higher than the reference voltage Vr, the output level of the comparator circuit 22 becomes a high level as shown in FIG. 3(g). Furthermore, since the output level of the inverter 26 is an inverted signal of the signal output from the selector switch 17 as shown in FIG. 3(h), the output level from the AND circuit 25 is as shown in FIG.
A high level pulse representing a transient state of the terminal voltage of the capacitor 21 is generated as a time signal as shown in FIG. In response to the generation of this pulse, the counter 27 is reset and counts clock pulses from the initial value. When the high level pulse disappears, the counter 27 stops counting and the count value is held in the latch circuit 29. The count value C held in the latch circuit 29 is compared with the reference value Cr in the comparison circuit 30. If the filament of the selected direction indicator lamp IL% or IR is normal and not broken, the terminal voltage of the capacitor 21 will drop rapidly, so the count value C
becomes smaller than the reference value Cr. Therefore, as described above, the output level of the comparator circuit 30 becomes a low level.

Assuming that the direction indicator lamp IL is selected by the activation switch 2, the direction indicator lamp I is selected at time t2.
In the case of an abnormality in which one of the filaments of L is broken, the load on the capacitor 21 is reduced, so the accumulated charge is turned off by turning off the relay switch 4, and the accumulated charge flows as a current only through the starting switch 2 and the other direction indicator lamp IL. Discharge. At this time, the rate of decrease in the terminal voltage of the capacitor 21 is slower than before the filament is disconnected, and after the relay switch 4 is turned off, the terminal voltage decreases to the reference voltage Vr.
Since the time it takes to reach Cr, that is, the time width of the high-level pulse output from the AND circuit 25, becomes longer, the count value C of the counter 27 becomes larger than the reference value Cr. Therefore, the output level of the comparator circuit 30 becomes a high level as shown in FIG. 3(j), and this high level causes the changeover switch 17 to
is driven and relays the first oscillation signal from the oscillator 15 to the base of the transistor 6 via the resistor 7.

Since the transistor 6 turns on and off in response to the first oscillation signal and intermittently supplies current to the relay coil 5, the blinking frequency of the other direction indicator lamp IL becomes higher (e.g., twice as high), giving direction indications to the driver, etc. This will notify you of a break in the filament of the lamp IL. This operation is the same even when one of the filaments of the direction indicator lamp IR is disconnected.

On the other hand, when the start switch 2 is turned off to the intermediate position,
The input voltage of the switch operation detection circuit 14 continues to be equal to the voltage Vcc. The switch operation detection circuit 14 changes from a high level output to a low level output when the input voltage remains equal to the voltage Vcc for a predetermined period of time (for example, 1.5 times the period of the second oscillation signal) after the input voltage rises. Since the signal is reversed, the oscillation operation of the oscillator 15 is stopped.

In the embodiment of the present invention described above, all operations are performed by hardware, but the terminal voltage of the capacitor 21 is A/D converted and supplied to the microprocessor, and the microprocessor performs a predetermined process. By repeatedly executing the program, it is also possible to obtain the operation of supplying the first oscillation signal or the second oscillation signal to the base of the transistor 6 via the resistor 7 in the same manner as described above.

Furthermore, in the embodiment of the present invention described above, when the filament of one lamp is broken, the lamp blinking frequency increases, but it may be lowered or the lamp may stop blinking and remain lit. .

Furthermore, in the above-described embodiment of the present invention, disconnection of the lamp filament is determined from the time it takes for the terminal voltage of the capacitor 21, that is, the stored voltage, to drop to the reference voltage Vr during the off period of the relay switch 4. but,
The present invention is not limited to this, and filament breakage may be determined from the voltage drop of the terminal voltage of the capacitor 21 per unit time.

Further, in the above-described embodiment of the present invention, it has been explained that filament breakage is determined according to the rate of decrease in the stored voltage of the capacitor, but as shown in FIG. It is also possible to connect the capacitor 21 in series with the I or IR series circuit, and determine whether or not the filament is broken according to the rate of increase in the charging voltage of the capacitor 21 when the transistor 6 is on. In the circuit shown in FIG. 4, the transistor 35
turns on when transistor 6 is off, and capacitor 21
It is provided to discharge the stored electric charge.

Effects of the Invention As described above, in the flasher device of the present invention, disconnection of the lamp filament can be detected from the rate of change of the stored voltage of the capacitor connected to the series circuit consisting of a plurality of lamps and the starting switch when the drive switch is activated. Since the current can be determined, there is no need to provide a current detection resistor in the current path of the lamp. Therefore, since power can be effectively supplied to the lamp, the illuminance of the lamp can be improved.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional example of a flasher device, Fig. 2 is a circuit diagram showing an embodiment of the present invention, Fig. 3 is a waveform diagram showing the operation of each part of the device shown in Fig. 2, and Fig. 4 is a circuit diagram showing a conventional example of a flasher device. FIG. 3 is a circuit diagram showing another embodiment of the present invention. Explanation of symbols of main parts IL, IR...Direction indicator lamp 2...
Starting switch 3... Current detection resistor 4... Relay switch 5... Relay coil 8.15... Oscillator

Claims (1)

[Claims] A flasher start switch connected in series to a plurality of parallel-connected lamps, a drive switch connected in series to the start switch, and a voltage applied to a series circuit consisting of the plurality of lamps, the start switch, and the drive switch. a capacitor connected to a series circuit consisting of the plurality of lamps and the starting switch; and a capacitor for repeatedly turning on and off the driving switch when the starting switch is on and storing electricity in the capacitor when the driving switch is activated. A flasher device comprising a drive means for changing the on/off frequency of the drive switch according to the rate of change of voltage.