JPS58209633A - Lamp disconnection detection device - Google Patents

Abstract

PURPOSE:To accurately detect disconnection when at least a single disconnected lamp of a number of lamps is detected while the lamps light out by providing a constant current circuit that supplies the constant current for detecting disconnection to the lamps instead of the resistors for detecting disconnection. CONSTITUTION:This disconnection detector circuit that detects the disconnection of a lamp 8 which is a tail lamp and a strap lamp contains a lighting lamp disconnection detector circuit A that detects the disconnection of the lamp 8 when the tail lamp switch S1 is ON. Besides, the circuit is provided with a constant current circuit C that supplies the constant current for detecting heat insulation to the lamp 8 when the lamp 8 lights off and detects the disconnection of the lamp 8 through a lighting-out lamp disconnection detector circuit D by the supply of the constant current when the lamp lights out. Furthermore, when the high level signal is output by each of the said disconnection detector circuits A and D while disconnection is being detected, an indicator lamp 9 lights after a preset delay time in a delay hold display circuit B and the generation of the disconnection is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to, for example, a lamp breakage detection device for a vehicle, and in particular to a lamp breakage detection device that detects a breakage of at least one lamp among a plurality of lamps when the rung is turned off (not in use). Regarding equipment.

Conventionally, as a disconnection detection device for a vehicle lamp, as shown in FIG. 1, a detection resistor R3 is connected in series with the lamp circuit.
When the lamp is turned on, the terminal voltage VL of the lamp 7 is detected, and this voltage VL is compared with the reference value. Detection of disconnection of lamp 7 to notify that lamp 7 is disconnected when the voltage is 1 compared to the normal condition.
3A placement is proposed.

However, when this type of lamp disconnection detection device attempts to detect a disconnection when a rung is turned off, the following problem occurs.

1) According to the graph in Figure 2, the detection range of the normal lamp and the disconnected part will change as the power voltage changes. In the graph (Curve 1 is the lamp power 1 when run 17 is lit normally with 4 lights on)
1--Current Tokutake curve, Curve 2 is the state where one run I is disconnected, that is, in the case of three lamps. resistance for detection R3
(for example, 17.IQ), the power supply 1" is 12V,
M in this case changes to 8V, i6V? ,! I and C are on the straight line. From these graphs, it can be seen that when 1 of the rungs is constantly lit, C is hot (, if 12 V is normally lit, 1 is +
1! The detection point is the intersection a of the J line 3 and curve 1, and when the normal power supply voltage is 12V when one Lannor lamp is disconnected, the detection point is the intersection co of the 1 line 3 and curve 2, but when the power supply When the voltage drops to 8V, these detection points become the intersections a1 and C1 of the white line 4, and in history, the power type [is 1
When 1-1 is applied to 6V, these detection points become the intersection points a2 and C2 of the curve 5) and change. Therefore, as can be seen from the graph, as the power supply type IE changes, the detection points CQ, C1, etc. at the time of disconnection, y, ", Xao,
There are cases where A- varies in the voltage j-1 region such as a2, and in this case, a stabilized power supply with a high 1ifi degree or a u
A table-type L1 circuit is essential.

2) In order to sufficiently detect the variation in the terminal voltage VL that occurs when the lamp is disconnected, it is necessary to make the value of the detection resistor Rs quite small.On the other hand, if it is made too small, the lamp may turn off. The lamp remains dimly lit. Therefore, one unit of the detection resistor R3 is approximately 1
It is necessary to use a large amount of setting power, and therefore a device with a relatively large power rating must be used.

3) Furthermore, as can be seen from the graph in Fig. 12, the detection range of the nonp m+ line, that is, 1
al, a 2. , and detection of disconnection r+';', c o
, CI, and C2 are relatively narrow, and there have been problems such as erroneous detection is likely to occur.The present invention is achieved by replacing the detection resistor Rs with a constant current circuit. To solve the problems described in 1-1-1 and 1.1, we provide a non-wire disconnection detection system that can easily and accurately detect the wire at which the lamp is turned off. There are things.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.13 Figure 3 shows an electric circuit of a lamp burnout detection device for detecting burnout of a 7-le lamp during automatic operation. +
2.1-3.14 There is a lamp C consisting of a square-shaped light bulb, which can be used as a car's sol lamp and a stop lamp.
- Run/disconnection detection circuit is connected to the Rou 21 circuit, which will be described later.
Detects a disconnection of the lamp ε3 at l(1)/in ■, r. Lamp disconnection detection circuit A when lit, disconnection from inverter 11 through die A-D4. Inputs the high level signal at the time of detection and a high level signal from a lamp breakage detection circuit for turning off the light, which will be described later, and turns on the indicator lamp 9 after a predetermined delay time and holds it. Constant current circuit C1 supplies a constant current for detecting disconnection to the run 18 when the lamp 8 is turned off.
To detect the end of the lamp 8'f voltage VL, the reference voltage 1-
1-Which comparison is used to detect lamp breakage? 11.
1 lamp disconnection detection circuit D and i-le lamp switch S
The detection prohibition circuit prohibits the disconnection detection operation of the run/disconnection detection circuit when the stop lamp switch 82 is turned on or when the stop lamp switch 82 is turned on, and when the light is turned off for a predetermined period after the stop lamp switch 82 is turned on.

Lamp burnout detection operation 8 during lighting is performed by passing lamp current through resistor R1 for detection 1, and increasing the voltage ffV on the negative electrode side of resistor R1.
L is detected and compared with the reference weight 1 by the comparator 11, and when the detected voltage VL rises above the reference voltage j1 when the lamp 8 is disconnected, a high level signal is output from the LO comparator]1, and this No. 18 is 4-1 to 1) are arranged to be sent to the delay hold display circuit [3 through 4-C.

The delay hold display circuit 13 is operated by human power (i is applied to I, 1 heran sister lr2, etc., 1 heran sister 1-r2 is connected to 2 ructors), NO
A node C2 for delay time connected between the output side of the gate N O'l and the gate N O'l and the j' gate.
, with the output side of Tsutoku 1~N01? Jji Genma Tsunol
Leak the indicator runno 9 connected through the gate NOR, input the high level signal detected at the time of disconnection to the /゛\-base of the transistor D'rz, and change it to a high level after the not gate time, Furthermore, Noagu h N 01
Change the output side of < to low level and run the indicator.
) lights up. Ignition connected to power supply E3aN
J N Mei FSA becomes A no, keep the lights on',
) is in operation.

Redundant current circuit 0 connects Turlington io) 1 to non-sister 1ra and this transistor 1 to 3.
1-1, comprising a 1-element comparator 13,
The reference voltage from the constant voltage 11 circuit having the two-way die A-do/1 is input to the inverting input terminal 33.

Historically, this constant current circuit C applies the voltage drop caused by the change in the load current IS of the resistor R2 connected to the collector of the transistor Tra to the non-inverting input terminal of the comparator 13, and compares it with the reference voltage. A differential voltage of 1 to C is applied to the bases of transistors R3 and Q operates to send a constant load current IS to the lamp 8.

The lamp disconnection detection circuit when the lamp is turned off is equipped with a =1 inverter 14, and the terminal voltage VL of the lamp 8 is applied to the non-inverting input terminal of the comparator 4, and the terminal voltage VL of the lamp 8 is applied to the inverting input terminal r of the comparator 4. The non-inverting input voltage 1) of the comparator node 14 is higher than the reference voltage. level 1
5 is output, and in response to lamp burnout (s, ti), this is sent to C delay hold display circuit [3] via diode D5, which is connected to J, .

The detection prohibition 11 circuit F is used when the i-le lamp mate 81 or the stop lamp switch S2 is switched on (and when the light is turned off for a few seconds, for example, at a constant voltage of 1 after non-lighting). Prohibit the disconnection detection operation of the lamp disconnection detection circuit [)11-
This is the lJth circuit that allows This means that when lamp 8 flashes, the end of the lamp Y'14L is near the power supply r+ or C1
This electric II is the light-out exit, and the r lamp disconnection detection circuit [
]' is applied to the 11 extreme r of comparator 4 and is applied to 6 /Komenikoko/JI L et I! 'i-line detection (the bow is output to the display circuit [3) (used to prevent it from being put away, and in history, after the non-f8 or i lights up, the lamp E' (
(Even when only the stop lamp is turned on, the tail lamp is affected by the heat.) The resistance value at lamp 8 is large, and the resistance value at lamp 8 is large.
Since the terminal constant voltage It' V L is higher than normal (and it is difficult to distinguish between wire breakage and other conditions), the wire breakage detection operation at this time is prohibited. When the lamp switch S2 is turned on at two o'clock (through the diode []9), a voltage 11 is applied to the bases of the transistors 1-rl through the diode Dg, 1, which is connected to the lamp disconnection detection circuit when the lamp is turned off.
It is configured to suck in the high level output from 4 through the diode O2, and the t-lamp switch S1 and the t-lamp switch S1 to the t-lamp main fS2 switch from A to A.
) to absorb the high level signal for 1 second after J's detection inhibit circuit 11 r' l, Z li
The comparator 15 is installed, and after this number of seconds, the output side of the comparator 15 is reduced to a low level, and the high level 11 from the 1 lamp disconnection detection circuit is sucked in through the diode D3. It is composed of =
] A constant voltage circuit including a Zener diode Z3 is connected to the inverting input terminal of the converter 15, and a constant voltage tl+ is applied to the ground, and the non-inverting input terminal is connected to a timer capacitor C1 connected between the ground. Pancreatic TN pressure L
As a result, the inverter 15 operates to absorb the high level for 10 seconds after the switch S1 or S2 is turned on.

Next, add 21 W '7 r for stop lamp to lamp 8.
5W-Noisymen l-4'
b゛) Using a double Noirament bulb, constant current circuit C
From run to 8! T11. 1゜Ignition Mates fS 3 A to J, constant current circuit C to tie A-t” I) 7 to eaves Z0
．． When a constant current to 65 is passed through the lamp 8, the terminal voltage VL of one terminal of the lamp 1 becomes about 09V as shown at the intersection aO of the curve 6 and the curve 1 in Fig. 1. becomes. Then, one of the lamps 11 to 14 of the lamp 8 is broken, and the electric current 11. at the end of the lamp is broken as shown at the intersection bo of the white line 6 and the curve 2 in Figure 1. V L is about 2,3 V nil 袢”lru.
+7), I:: rf? L//1. : Input voltage n゛ based on power 11 goes out 1・r Symb disconnection detection circuit l) -
”The smell of the generator 14 (compared with the reference voltage 1.6V, human power electric [[Ka uiv-electric!
” A high-level Shinkyu can be output from the Embalerator 1/I. This height is l\rujT+ ”; L yo Guiod D
Light C slow court hall 1! Transistor off of display circuit 13'
It is applied to the base of r2, transistors]1 and 2 are conductive, and the collector potential of
The output side of I is connected to capacitor c2 by J, <) and becomes a high level due to the extended time contact, and the output side of NOAR game 1-NOR becomes a low level, and a current flows to the indicator lamp 9 from the non-electronic side. The burnout of the lamp 8 is notified.This lighting is maintained until the light switch 3 is turned off.

On the other hand, when the tail lamp is lit, the voltage drop of the lamp circuit A is detected by the detection resistor R1.
If any of the 7-- and 1-2 volts is connected to the linear g (if any), the voltage on the negative electrode side of 1 will rise in the detection resistor 1, and the voltage applied to the 11-pole terminal of the comparator 11 to the lamp burnout detection circuit during lighting will increase. Since the voltage exceeds the reference voltage, the output side of the 21 comparator 11 rises to a high level, and the diode D4
A high level signal is applied to the penis of delay bold display circuit B 1 to transistor 11゛2 through oJ, teL
Same as above [・Syndistor 1r2 is conductive, and the horn is closed.
Since the output side of -NOR is at a low level, a current flows through the indicator lamp 9, indicating that the lamp 8 is disconnected.

When the sol lamp is lit, it is passed from the T-ru lamp make fs+ to the die Δ- 9 - (and when the stop lamp switch S2 is turned on, it is passed from the stop lamp switch S2 to the tie/I-1・[) 8 10 detection prohibited. +11i';
A cell is applied to the base of transistor 1-rl of path 1 to make it conductive. Therefore, when lamp 8 is lit (
J end A In this case, this high-level signal is sucked into the transistor 11-1 through the die A-1'D2, and the lamp disconnection detection circuit O(
7) Erroneous detection operations can be prevented (-).Furthermore, immediately after the lamp and sol lamps are extinguished, the lighting of the filament lamp heats up and the power bar is turned off. Although it is higher than usual, at this time, the output side of the comparator 5 is turned off by the series C1 (J is lowered to a low level, and the light indicated by L is turned off via the diode D3. By absorbing the high level YES signal output from the target rung disconnection detection circuit 1,
After the lamp is turned off, the detection of 1lit6A by this detection circuit I is prohibited for a predetermined period of time, for example, several seconds, to prevent false detection.
I'm here.

As shown in Fig. 4, the constant current circuit C is equipped with an f-jumping circuit F, and the constant current circuit C (!- operates intermittently. The operating time t of the constant current circuit C on the other hand is determined by taking into consideration the rising time of the voltage II-vL of the lamp 8 and the delay time of the delay hold display circuit B, for example, approximately Set it to about 4 seconds.

Further, the operation cycle] is, for example, about 1 minute.

As described above, the present invention is a lamp breakage detection device that detects a breakage in at least one of N number of lamps when the lamps are turned off, and includes a constant current that supplies a constant current for burnout detection to the lamp. Manually compare the terminal voltage of the lamp that occurs in the circuit and the constant current with V
It is equipped with an IJ lamp disconnection detection circuit and an IJ lamp disconnection detection circuit.

Therefore, as shown in the graph of FIG. f is less sensitive than -, and the difference between the detected voltage when the lamp is in normal condition and when the lamp is disconnected is less sensitive, so if the setting range of the standard 11ifT is wide < 4C, j(,
It is possible to easily and accurately determine the disconnection (・
Monkey. Therefore, compared to the conventional detection N path, it is possible to integrate the base current LI generation circuit etc. into the cylinder, and the variation in characteristics of each component can be avoided.
b Sufficient M' (can be accommodated.Furthermore, the conventional disconnection detection U8]1
If you connect the 0 line to a lamp circuit used in a -C circuit, the resistance for detecting the rated power will not reach the rated power.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional disconnection detection circuit, and Fig. 2 is an explanatory diagram of a conventional disconnection detection circuit.
Current characteristics: Fig. 3 shows an embodiment of the present invention; Fig. 4 shows the configuration of the main parts of another embodiment; Ramp 11.13.14.15...-' Ramp 11.13.14.15...-'
・J-le lamp switch SL...Stop lamp switch A...Lighting switch disconnection detection circuit B...Delay hold display circuit C...Constant current circuit 1)...Lamp disconnection detection circuit when turned off E...Detection prohibited l] Circuit [...Chi31 Tsubing circuit attorney Patent attorney 1 Tsutomu Adachi

Claims (1)

[Claims] At least 101 of the plurality of lamps when the lamp is turned off
This is a lamp burnout detection device that detects burnout of a lamp.It inputs a constant current circuit that supplies a constant current for burnout detection to the lamp, and the terminal voltage of the lamp generated by the constant current and compares it with a reference voltage. 1. A lamp breakage detection device comprising: a lamp breakage detection circuit when the lamp is turned off;