JPS58167236A - Switch circuit for car room lamp - Google Patents

Abstract

PURPOSE:To obtain a simplified protector circuit which assures less surgings for input signals, by forming a switching circuit with a T-flipflop and an R-S-flipflop and by interposing a door switch circuit between the emitter of output transistor and the ground. CONSTITUTION:When voltage of a voltage stabilizing circuit 13 is supplied, a T-FF (flip-flop) 1 and an R-S-FF (flip-flop) 2 will be reset in the initial period. When a manual operational switch 3 thereafter is given a push, the Q terminal of T-FF 1 is turned to H to light up a room lamp 10. If another push is applied, the Q terminal is turned to L and the lamp 10 will be put out. When by contrast a door-interlocked operational switch 4 is given a push, the Q terminal of P-S-FF 2 is turned to H, but the lamp 10 is not lighted up because a door switch 7 between the transistor 6 and ground is off in the initial period. If the switch 7 is turned on, the lamp will now be lighted up, which is put out by pushing the switch 4 again. Accordingly input signals to electronic circuits have less trouble about being mixed with surger noises to assure a simplified protector circuit as well as a reduced space for the reset circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electronic switch that selects whether to turn on and off a room lamp manually or by opening and closing a door, and turns it on and off when it is manual by operating a button on the switch. The present invention relates to a switch circuit for an automobile room ring.

In general, a car room lamp will always turn on if you turn on the ``@0N-Door-OFF'' selector switch installed inside the room lamp's lighting fixture.
”, the light will turn on when the door is opened and turn off when the door is closed, @O
The circuit is configured so that the light is always turned off when set to ``FF'', and normally the changeover switch is set to ``Door'' and the light is turned on and off when the door is opened and closed.

Conventionally, in the switch circuit for such a room lamp, a rotating or sliding mechanical switch is used as the changeover switch, and the rung current is directly turned on by this switch and the door switch.

There are some that turn off and then turn on and off. Although such conventional circuits have the advantage of being extremely simple in configuration, they do not allow direct ON/OFF of the lamp current using a mechanical switch.
This causes various problems such as deterioration of the switch contacts and the generation of noise.Furthermore, the switch cannot be operated with one touch, and the switch lever must be rotated or slid, which is cumbersome. . (In this specification, one-touch operation literally refers to one contact operation using a touch switch, and also includes one suppressing operation 4 using a bushing switch.) Therefore, recently, conventional circuits such as those described above have been developed. In order to solve these problems, and in conjunction with the trend toward electronic circuits for other automobile control circuits, it has been considered to use electronic switch circuits for room lamp switch circuits.

This can be turned on with a one-touch operation as an operation switch.
In addition to using a touch switch to turn off, a push switch is used, and a conductor switch is used to turn ON and OFF the current of the amplifier, and most of the circuits between the operation switch and the amplifier are integrated into ICs. However, in this type of switch circuit that has been considered so far, the door switch is completely OFF, that is, the door switch is ON.

It is not possible to manually turn off the room lamp by turning off the circuit that turns the room lamp on and off from OFF K. Therefore, such a switch circuit can be used as the above-mentioned general '0N
-Door-OFF" changeover switch was not completely achieved.Also, since the door switch is connected to the input side of the switch circuit, the door switch itself and the circuit provided for the door switch, For example, surges or noise from other circuits, such as a circuit to prevent forgetting to turn off a room lamp, are easily mixed in, and therefore, a sufficient protection circuit is required to protect electronic circuits such as ICs from these surges.Furthermore, , a C-R integral type circuit is used for the reset circuit that resets the switch circuit in the initial state, and it is configured to reset according to the charging time of C, so the rise time of the switch circuit becomes longer and the This had the disadvantage that it took up a large amount of space, making the circuit a bit of a dog's game.

The present invention was made in order to eliminate the above-mentioned drawbacks, and it is possible to completely turn off the door switch and achieve the same function as the conventional general "ON-Door-OFF" changeover switch. In addition, it is possible to simplify the protection circuit on the input side, reduce the space occupied by the reset circuit, and speed up the start-up of the circuit. purpose.

The present invention will be described in detail below with reference to FIGS. 1 and 2.

FIG. 1 is a diagram schematically showing an embodiment of a switch circuit for an automobile room lamp according to the present invention. In the figure, 1 is a T-FF (T flip-flop) with a reset terminal, and 2 is an R-
8-FF (R-8 flip-flop), 3 is a one-touch operation, here one suppression operation causes T-FF
A manual operation bushing switch that supplies one pulse to the T input terminal T of I and the reset terminal R of R-8-FF2 (this is called a manual operation switch); 4 is also 1
This is a button switch for interlocking door operation (this is referred to as a switch for interlocking door operation) which supplies one pulse to the set terminal S of R-8-FF 2 by one suppression operation.

5 is an NP that is turned on and off by the output signal of T-FFI.
An N-type transistor 6 has its collector commonly connected to the transistor 5, and is turned on by opening and closing a car door (not shown) between the two terminals and ground.

This is an NPN type transistor connected to the door switch 7 which is turned off, and turned on by the output signal of R-8-FF2.

Turn off. Reference numeral 8 denotes a PNP type switching transistor whose bases are commonly connected through a resistor 9 and connected to the collectors of transistors 5 and 6. It turns on when the transistor 6 and the door switch 7 are both in the on state. 10
is the set terminal S of the room 2 ring, 111d, and R-8-FF 2, which is energized through the switching transistor 8 and lights up when the switching transistor 8 is turned on.
and output terminal Q, here output terminal Q
The priority circuit connected between the T-FFI and the reset terminal R of the T-FFI is a diode that also serves as a reverse current blocking circuit.

12 is T- during the rise of the voltage when the power is turned on.
This is a reset circuit that supplies a reset signal to each of the FFI and R-8-FF 2 to instantaneously reset them in their initial states, and includes a Zener diode, a resistor, and an inverter (not shown). Reference numeral 13 indicates a voltage stabilizing circuit for making the voltage of the positive power supply (G) constant, and reference numerals 14 to 16 indicate diodes for blocking reverse current.

FIG. 2 is a diagram showing a specific example of the circuit of the present invention shown in FIG. 1. Hereinafter, the present invention will be explained in detail based on FIG.

In FIG. 2, 1 to 16 and (g) are the same as in FIG. 1, respectively. In this case, one end of the manual operation switch 3 is grounded, and the other end is connected to the output end of the voltage stabilization circuit 13 via the pull-up resistor 17 and connected to the constant voltage power supply line 18, and is also connected to the surge prevention Condenser t 19t-
It is further connected to the input terminal of the inverter 210 via an input protection resistor. The output terminal of this inverter 21 is connected to the T input terminal T of the T-FF 1 and is also connected via the diode 14 to the reset terminal R of the R-8-FF 2. The door interlock operation switch 4 has one end grounded, the other end connected to the power supply line 18 via a pull-up resistor 22, and grounded via a surge prevention capacitor n, and further connected to an input protection resistor. It is connected to the input end of the inverter δ via the power line. The output terminal of this inverter is the set terminal SK of R-S-FF2.
Connected.

9. As shown in the figure, the reset circuit 12 has a Zener diode 12m and a resistor 12b connected in series between the power supply line 18 and the ground, and an input end connected to the connection point between the Zener diode 12m and the resistor 12b. The output terminal (output terminal of inverter j'12e) is connected to T-F via a diode 15.
It is connected to the reset terminal R of FI, and also to the reset terminal R of R-8-FF2 via the diode door 6. In this case, the Zener diode 12m
The Zener voltage is set to be slightly smaller than the output voltage of the voltage stabilizing circuit 13 minus the minimum operating voltage of the ICs constituting the T-FFI, R-8-FF2, etc.

26 is a resistor interposed between the output terminal Q of T-FFI and the base of the transistor S, 27 is a resistor interposed between the output terminal Q of R-8-FF2 and the base of the transistor 6, and the decoy is the resistor of the transistor 6. and door switch 7
This is the resistance that exists between them.

In addition, 29 to 38 constitute a switch circuit that turns on and off the room lamp 39 with one-touch operation independently from the above-mentioned circuit, and 29 is a manual operation switch consisting of a bushing switch whose one end is grounded. , () is a pull-up resistor interposed between the other end of the switch 4 and the power supply line 18, and 31 is a surge prevention capacitor interposed between the other end of the switch 29 and ground. 32 is a resistor, the input terminal is connected to the other end of the switch 4 through the resistor 32, and the arm is a T-FF, whose T input terminal T is connected to the output terminal of the inverter 33, and a reset terminal. R is connected to the output terminal of the inverter 12e of the reset circuit 12. 35 is a resistor, 36 is a base with a resistor 3
an NPN transistor 3 connected to the output terminal Q of the T-F]i'34 through 5 and having a grounded claw;
7 is a resistor, 38 is a PNP type switching transistor whose base is connected to the collector of the transistor 36 via the resistor 37, whose emitter is directly connected to the power source 0), and whose collector is grounded via the room lamp 39.

Next, the operation of the circuit of the present invention having the above configuration will be explained.
First, when the power supply (G) is turned on, the output voltage of the voltage stabilization circuit 13 is applied to the IC and reset circuit 12 that constitute the T-FFI and R-8-FF 2, etc. via the power supply line 18. be done. At this time, the Zener diode 12
Since the Zener voltage of the inverter 12e is set to be slightly smaller than the output voltage of the 1-voltage stabilizing circuit 13 minus the low operating voltage of the IC, the output signal of the inverter 12e is
During the rise of the output voltage of the voltage stabilizing circuit 13, it becomes a no-y level, and when it has completely risen by 1, it is inverted to a low level. Therefore, T-FFI and R-8-FF
A reset signal is supplied to each of the transistors 2 at the moment of application of the operating voltage, and they are instantaneously reset (initialized reset) in their initial state.

From this state, when the manual operation switch 3 is operated once, a signal from the output terminal of the inverter 21 changes from C, low level to high level, and then from N1 level to low level, that is, a positive signal. A single pulse is output. This pulse is input to the 1'' input terminal T of T-1''Fl, and its rise inverts the output terminal Q of '1'-FFI from low level to high level.

Therefore, the transistor 5 is turned on, and the transistor 8 is also turned on, and the room lamp 10 is turned on. After that, when the manual operation switch 3 is pressed once again, T-F
The output terminal Q of the FI is inverted again and returns to the original low level, so that the transistor 5 is turned off and at the same time the transistor 8 is turned off and the room lamp 10 is turned off. Na@0N-Door
This corresponds to the operation when the -OFF' changeover switch is operated "ONMOFF". Furthermore, each time the manual operation switch 3 is suppressed, a current is also supplied to R-8-FF2,
All of them are R-8-FF 2.1) Set terminal R
Therefore, the output terminal Q remains at a low level and does not change at all.

Next, when the door interlocking operation switch 4 is pressed once from the initial state, the output terminal of Inno (-Yuho) changes from low level to 7. A signal, ie, one positive pulse, is output. This pulse is input to the set terminal S of R-8-FF2, and the output terminal Q of R-8-FF2
is inverted from low level to high level and transistor 6
is in the ON state, but since the door switch 7 between the socket and ground is OFF, the transistor 8 is in the OFF state.
No, room 2 lamp 10 does not light up. When the door switch 7 is turned on in this state, the transistor 8 is turned on and the room lamp 1O lights up. This corresponds to the operation when the door interlock operation switch 4 is depressed.
-8-FF The high level signal from the output terminal of 2' is T
- It is supplied to the reset terminal R of FFI, but at this time T
Since -FF'1 is in the reset state, the output terminal Q of T-FIi'l remains at a low level and does not change at all.

Next, from the initial state, the manual operation switch 3 is suppressed once to invert the output terminal Q of the T-FFI to high level, and the door interlock operation switch 4 is pressed once to turn on the room lamp IO. When pressed, the output terminal Q of R-8-FF 2 becomes high level. This high level signal is supplied to the reset terminal B of T-FF1 through the diode 11, resets the T-FFI and inverts its output terminal Q to low level, and the transistor! Turn 5 off. On the other hand, when the output terminal Q of R-8-FF2 becomes high level, the transistor 6 is turned on, and the room lamp 10 is thereby activated by suppressing the door interlocking operation switch 4 once from the initial state. Similarly, the O of door switch 7
The light turns on and off depending on N and OFF. Such an operation corresponds to the operation when the "ON-h Door" switch is operated as described above.

Next, the door interlocking operation switch 4 is suppressed as described above, and the manual operation switch 3 is suppressed once from a state where the room lamp 10 is turned on and off by turning the door switch 7 ON and OFF. Then, the pulse from the output terminal of the inverter 21 passes through the diode 14 to R
-8-F'F2 is supplied to the reset terminal R of R-8-
Set FF2 t17. Therefore, R-8-FF
The output terminal Q of 2 is inverted from high level to low level,
Transistor 6 is turned OFF'. On the other hand, the pulse from the output terminal of the inverter 21 is also supplied to the T input terminal T of T-FFI, but T-FF'1 operates at the rising edge 9 of the pulse, and at the rising edge R -8-FF2 output terminal Q has not yet been inverted to low level and remains high level, so T-FFI
The reset will not be canceled. Therefore, T-FF
The output terminal Q of I remains at low level, and the door switch 7 is completely OFF, that is, the door switch 7 is ON.
, OFF turns off the circuit for turning on and off the room lamp 10, and the room lamp 10 is turned off manually. However, if the manual operation switch 3 is pressed once again from this state, this time the T-
Since the FFI reset has already been canceled because the output terminal Q of 84-FF2 maintains a low level, T
-FFI output terminal Q is inverted to high level. Therefore, transistor 5 turns on and transistor 8 turns off.
NL, the room lamp 10 lights up. This kind of operation is the same as the @0N-Door-OFF "selector switch" mentioned above.
This corresponds to the operation when "Door −+ OFF" and "OFF→ON" are operated.

Note that the manual operation switch 4 is the same as the manual operation switch 3.
A room lamp 39, which is separate from the door interlocking operation switch 4 and separate from the room lamp 10, is turned on and off by a suppressing operation. In other words, when the manual operation switch 4 is depressed once, the inverter 3
One positive pulse is output from the output terminal of 3. This pulse is applied to the T-FF34, which is instantaneously reset in the initial state, similar to the T-F'FI and R-8-FF2.
It is input to the T input terminal T of
flip it to the flat level. Therefore, transistor 36 is
At the same time, the transistor 38 turns ON and the room lamp 39 lights up. After that, the manual operation switch 29
When the output terminal Q of the T-FF 34 is inverted once again and returned to the original low level, the transistor 36 is turned OFF and the transistor 381 is also turned OFF.
L, the room lamp 39 is turned off.

In the illustrated embodiment, the diode 11 which is the priority circuit
was connected between the output terminal Q of 5-R-FF2 and the reset terminal R of T-FFI, and the light-off priority operation was performed as described above. It may be provided between the reset terminal R of the T-FFI, and in this case, the lighting priority operation is performed.

That is, the door interlocking operation switch 4 is now suppressed, the output terminal Q of T-FFI is at a low level, and the R-8
-The output terminal Q of FF 2 is at high level, and the room lamp 10 is crushed by turning the door switch 7 ON and OFF.
When the manual operation switch 3 is pressed once from the state where the light is turned off, a pulse from the output terminal of the inverter 21 is supplied to the reset terminal R of R-8-FF2 via the diode 14, resetting R-8-FF2. do. Therefore, R-
The output terminal Q of the 8-FF2 is inverted to a high level, low level, and the transistor 6 is placed in the 01i'F state. On the other hand, the output terminal of the inverter 21 is also supplied to the T input terminal T of the Calanova filter T-FFI. Here, diode 11
is connected to the set terminal S (of 9, R-8-FF2) and the reset terminal R of T-FFI, which is different from the illustrated position.
T-FFI reset) [Child R is at low level except when the door interlocking operation switch 4 is being suppressed, so as mentioned above, the child R is supplied to the T input terminal T of the T-FFI) Then, the output terminal Q of T-FFI is inverted from low level to high level. Therefore, transistor 5 is turned on.
At the same time, transistor 8 turns ON, room lamp l
Since O is lit, priority is given to lighting.

(9) In the above-mentioned embodiment, a case was described in which a bush switch was used as a switch operated with one touch, but a touch switch may also be used.

As described above, the present invention provides T-FF and R-8-F
Since it is configured as described above using Ft-, it is possible to completely turn off the door switch, which is different from the conventional "
0N-Door-OFF" changeover switch. Since the door switch is not connected to the input side of the circuit, but between the output side of the transistor and ground, the T-FF+R-8 -I constituting FF etc.
There is little surge or noise mixed into the input signal of the electronic circuit such as C, and a simple protection circuit is required for the electronic circuit. Furthermore, the reset circuit is constructed using a Zener diode, a resistor, and an inverter instead of a conventional C-R integral type circuit, which reduces the space occupied by one circuit component and speeds up the start-up of the circuit. I can do it. In addition, two different priority operations can be selected by simply switching between connecting one end of the priority circuit to the set terminal of R-8-FF or connecting it to the output electronics, which is convenient. .

Brief explanation of the drawing 2
FIG. 1 is a diagram schematically showing an embodiment of the -switch circuit for an automobile room compartment according to the present invention, and the second tsubo diagram is a diagram showing a specific example of the circuit of the present invention shown in FIG. 1.

l...T-FF, 2...R-8-FF, 3
... Manual operation switch, 4... Door interlocking operation switch, 5.6... Transistor, 7... Door switch, 8... Switching transistor, 10...
Room lamp, 11...Diode (priority circuit), 1
2... Reset circuit, 12a... Zener diode, 12b... Resistor, 12c... Inverter, 13
...Voltage stabilization circuit, (g)...10 power supplies.

Claims (1)

[Claims] 1. T-FF and R-8-FF with reset terminal,
a first switch that supplies a signal to the T input terminal of the T-FF and the reset terminal of the R-8-FF through one-touch operation; and a first switch that supplies a signal to the set terminal of the R-8-FF through one-touch operation. a second switch, and the T-
A first transistor that is turned on and off by the output signal of the FF, the collector of which is connected in common, and the emitter and ground that are turned on and off by opening and closing a door.
, said R-8 to which a door switch to turn OFF is connected.
- Turns ON and OFF by the FF output signal #! 2 transistor, a semiconductor switching element that is turned on when current is applied to one of the first and second transistors, and a 0 transistor of this semiconductor switching element.
At 8 o'clock, a room lamp that is energized and turned on via the semiconductor switching element is connected between one of the set terminal and output terminal of the R-8-FF and the reset terminal of the T-FF. A Zener diode and a resistor are connected in series between the priority circuit, the circuit power supply, and the ground, and the input end of the inverter is connected to the connection point of these Zener diodes and the resistor. A switch circuit for a room lamp for an automobile, comprising a reset circuit that supplies a reset signal to each of T-F)' and R-8-FF and resets them in an initial state. 2. The switch circuit for an automobile room lamp according to claim 1, wherein the first and second switches are touch switches or bush switches.