JPS643692B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle flashing device mainly used as a direction indicator of a vehicle.

As part of measures to prevent large vehicle left turn accidents, the Ministry of Transport has mandated that more turn signal lights be used, and social conditions have led to a wide variety of needs, including the number of turn signal lamps, the load current of the lamps, and the conditions under which they can be installed on vehicles. There is a need for a disconnection detection device for flashers to meet these needs.

Figure 1 is an example of a typical circuit of an existing transistor type flasher with disconnection detection. The current system shown in Figure 1 only detects the disconnection of one light, and cannot distinguish between the disconnections of two or more lights.

In the event of a disconnection failure, the present invention can notify the driver of the extent of the failure, that is, whether it is one light disconnection or two or three more lights, and prompts the driver to take appropriate measures. It is an object of the present invention to provide a flashing device for a vehicle that can be used in a vehicle, whose characteristics do not vary greatly due to temperature changes, and whose characteristics can be easily adjusted.

Examples of the apparatus of the present invention will be described below.

In FIG. 2 showing the first embodiment, 1 is a battery that serves as an in-vehicle power supply, 2 is a vehicle fuse, 3 is a flasher body, 4 is a turn signal switch, and 5 is a
is a hazard switch, and 6a to 6d and 7a to 7d are lamp groups on the right and left side of the flasher lamp. Reference numeral 8 denotes a blinking section of the flasher, which is formed by turning on and off a relay coil 9 and a contact 10 using a blinking capacitor 11 and transistors 12 and 13. 24 is a resistor for detecting load current, 25 is a reference voltage circuit which includes a Zener diode 101 and a resistor 102,
103, 104, and 105 provide fluctuation characteristics based on the power supply voltage close to the lamp load current.

26 forms a comparison amplifier circuit. The PNP transistor 106 is a detection transistor, and its base potential is given by an emitter follower circuit including an NPN transistor 107 and a resistor 108.
Temperature compensation for V _BE (base-emitter voltage) of transistor 106 is given by V _BE of transistor 107. Adjustment resistor 109 is transistor 106
The resistor 110 controls the charging voltage of the flashing capacitor 11 when the transistor 106 is turned on, and the resistor 110 controls the charging voltage of the flashing capacitor 11 between the resistor 21 and the resistor 110.
Clamp at the partial pressure ratio of , and make it flash faster. The resistor 112 clamps the charging voltage of the blinking capacitor 11 and keeps it constant when the transistor 106 is OFF. As a result, the number of blinks can be increased, and the lighting rate does not change much. Note that L is a terminal, 14 and 20 are resistors, 22 and 23 are diodes, and 15 and 166 are capacitors.

Next, the operation will be explained. When turn signal switch 4 is turned on when the lamp load is normal, current flows from power supply 1 through resistors 16, 17, and 18, and resistor 1
When the voltage drops by 6, the transistor 12 turns on, and then the transistor 13 turns on, and the contact 10 closes and lights up. At this time, the capacitor 11 is charged from the power supply 1 via the resistors 16 and 17, the capacitor 11, the resistor 21, and the transistor 13. However, full charging of the capacitor 11 is suppressed by the voltage divided by the series resistance of the resistors 112 and 110 and the resistance of the capacitor 11.

When the capacitor 11 is completely charged, the transistors 12 and 13 are turned off, the contact 10 is turned off, and the lamp is turned off. When the transistor 12 is turned off, the capacitor 11 is connected to the resistors 17 and 16, the coil 9, and the resistor 2.
1. Discharge in the path of capacitor 11 and keep transistor 12 off. capacitor 11
When the discharge weakens, transistor 12 turns on again.
Then, it lights up again and blinks repeatedly. By providing the resistor 112, the electric potential on the left side of the capacitor 11 is raised, charging of the capacitor 11 is completed quickly, and the flashing is made faster than when the resistor 112 is not provided.

Next, let's talk about disconnection. Reference voltage circuit 25
In the standby mode, when the turn signal switch 4 is in the neutral state as shown in Fig. 2, no current flows through the current path of the power supply 1, fuse 2 terminal B, and terminal E, and the flasher but
When ON, that is, only when transistor 13 is ON,
A current flows through the reference voltage circuit 25 to make it work. The output of the reference voltage circuit 25 is approximated to the current characteristics of the lamp. The transistor 106 is connected to the voltage drop of the load current detection resistor 24 and the transistor 10
V _BE of 6 and the applied voltage of terminal B and transistor 10
It is controlled by the base voltage of 6 and turns on. Then,
Resistor 24, transistor 106, resistor 110,2
1. A current path is created for the transistor 13, and the charging voltage of the capacitor 11 is clamped according to the voltage division ratio of the resistors 110 and 21. This raises the potential on the left side of the capacitor 11 as described above, so that charging is completed quickly and the blinking is accelerated. Note that the voltage characteristics of the load current detection resistor 24 are canceled by the reference voltage circuit 25, and the voltage characteristics of the transistor 1
The voltage and temperature characteristics of V _BE of transistor 1
By canceling with _VBE of 0.07, a disconnection detection circuit with good voltage-temperature characteristics is formed.

In addition, when the transistor 106 is in the active region (amplification region), the resistor 109 causes a current to flow through the resistor 109, and a voltage drop occurs in the resistor 109 according to the amount of current flowing through the resistor 109. Therefore, the rise characteristic during switching becomes gradual. The characteristics are inclined to . For this reason, the slope characteristics are appropriately adjusted by selecting the resistor 109 to an appropriate value, and when one lamp is disconnected, the transistor 106 is placed in the active region (amplification region), and when two lamps are disconnected, the transistor 106 is placed in the saturated state, for example. If you set it to ) The number of blinks can be determined by the number of broken lamps.

Next, in FIG. 3 showing the second embodiment, a reference voltage circuit 25 is composed of resistors 201, 202, 203, 205 and a diode 204.

This generates a reference voltage matched to the lamp current and operates in the same way as the first embodiment.

Next, the third embodiment is as shown in FIG.
The flashing circuit is different. In this case, when waiting,
Unlike the first embodiment, the capacitor 11 is fully charged. Further, 22a is a diode.

As described above, in the present invention, the PNP transistor 106 and the NPN transistor 107 are connected in a complementary manner so as to cancel out the characteristic fluctuations caused by the ambient temperature. Failures can be prevented, and the failure state of the lamps can be accurately recognized even if there is a temperature change in a device like the present invention, where the blinking cycle changes depending on the number of broken lamps. In addition, the PNP transistor 106
Since the adjustment resistor 109 is provided between the emitter of the PNP transistor 106 and the load current detection resistor 24, the output characteristics of the PNP transistor 106 can be adjusted, and the comparison amplifier circuit 2
Since the slope characteristic of the output No. 6 can be set arbitrarily, the blinking characteristic can be set according to the vehicle type. Furthermore,
It is possible to tell whether one, two, or more lamps are broken by the number of flashes, and the driver can be prompted to take appropriate measures, instead of the conventional method where multiple lamps are broken. It is possible to prevent the vehicle from driving without any treatment.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram of a conventional device, Fig. 2 is an electric circuit diagram showing a first embodiment of the device of the present invention, and Figs. 3 and 4 show second and third embodiments of the device of the present invention. A partial electrical circuit diagram. 3... Flasher body, 6a to 6d, 7a to 7d
...Flash lamp, 24...Resistor for load current detection, 25...Reference voltage circuit, 26...Comparison amplifier circuit,
106...PNP transistor, 107...NPN transistor, 109...adjustment resistor.

Claims (1)

[Claims] 1. Vehicle flash lamps 6a to 6d, 7a to
A load current detection resistor 24 that converts the magnitude of the lamp load current flowing through the terminal 7d into a voltage, and a reference voltage circuit 25 that generates an output voltage that approximates the fluctuation of the lamp load current when the vehicle power supply voltage fluctuates. , the first output voltage of the reference voltage circuit 25 and the second output voltage of the load current detection resistor 24 are compared, and the larger the second output voltage is than the first output voltage, the higher the own output voltage. a comparison amplifier circuit 26 which increases in size and operates to detect at least one lamp disconnection failure in the amplification region; and a comparison amplifier circuit 26 whose blinking cycle becomes shorter in approximately proportion to the magnitude of the output voltage of the comparison amplifier circuit 26, which causes the flashing lamps 6a to 6d, It includes a flasher body 3 that blinks 7a to 7d, and the flasher lamps 6a to 6d, 7a to 7d.
As the number of broken wires increases, the blinking period of some of the flasher lamps 6a to 6d, 7a to 7d that are not broken is shortened approximately proportionally, and the comparison amplifier circuit 26 reduces the output voltage of the load current detection resistor 24. is connected to the emitter of the PNP transistor 106, the collector of which constitutes the output of the comparison amplifier circuit 26, the output voltage of the reference voltage circuit 25 is connected to its base, and the emitter of the PNP transistor 106 is connected to the base of the PNP transistor. A flashing device for a vehicle, comprising an NPN transistor 107 and an adjustment resistor 109 provided between the emitter of the PNP transistor 106 and the load current detection resistor 24.