JPH0332443Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply for a multiple harness system in a multiple harness system.

In recent years, the number of electrical components in automobiles has increased significantly due to the addition of advanced functions.
Multiple harness systems are being adopted to simplify and reduce the weight of wire harnesses. In this multiple harness system, a terminal containing a built-in microcomputer, etc. is installed in the car, and electrical components such as switches, sensors, and lamps are temporarily connected to the nearest terminal, and the electrical components that serve as loads are transferred through multiplex transmission between the terminals. It is operated based on information from switches, etc.

However, since a large amount of electronic circuits and electrical components are used in the multiple harness system, the power consumed by these components is also considerably large. Therefore, it is desirable to reduce battery power consumption as much as possible.

Therefore, the present invention reduces power consumption by supplying power only when the system is desired to operate in multiple harness systems such as automobiles, and also provides a power source for multiple harness systems that stops supplying power when the battery has an abnormal voltage. The purpose is to provide.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows the circuit configuration of the first embodiment of the present invention, where 1 is a battery, 2 is a multiple harness system, and 3 is a key switch (ACC is an accessory, IG is an ignition contact, and ST is a starter contact. ), 4 is switches other than the key switch, 5 is a relay that connects the battery to the multiple harness system, and 6 is a transistor control circuit for driving the relay. Further, Q ₃ is a transistor that constitutes a circuit that operates the transistor control circuit 6 when the key switch 3 is turned on to ACC.
A, B, and C indicate comparison circuits. Comparison circuit A detects an abnormality when the battery voltage becomes low, and comparison circuit B detects an abnormality when the battery voltage becomes high. Comparison circuit C detects when key switch 3 is turned on to ST and controls the operation of transistor control circuit 6.
Turn it off. Note that the circuit consisting of transistors _Q4 and _Q5 is a holding circuit that keeps the system operating even if the switch is turned off.

The transistor control circuit 6 is composed of transistors Q ₁ and Q ₂ whose collectors are connected to _the excitation coil of the relay 5, respectively.
When both _Q2 are ON, relay 5 operates and battery 1 is connected to multiple harness system 2.
The emitter of transistor Q ₁ is always a diode D ₁
connected to battery 1 through
A bias voltage is applied from the collector of Q ₁ to transistor Q ₂ by resistors R ₁ and R ₂ . Therefore,
When transistor Q ₁ turns on, transistor Q ₂ turns on.
is activated. In addition, diode D ₁ is battery 1
This is a reverse voltage prevention diode that prevents reverse voltage from being applied to each circuit if it is reversely connected.
D ₂ then protects transistors Q ₁ and Q ₂ from reverse voltages. Further, D ₃ and D ₄ are diodes for protecting the transistors Q ₁ and Q ₂ .

The transistor _Q3 that operates the transistor control circuit 6 when the key switch 3 is turned on ACC has its collector connected to the base of the transistor _Q1 via the resistor _R5 , and its base side connected to the ACC contact of the key switch 3. It is connected. Therefore, when key switch 3 is turned on to the ACC contact, battery 1 increases the base voltage.
It becomes High and transistor _Q3 turns on. Along with this, the base voltage of transistor _Q1 becomes low.
As a result, the transistor control circuit 6 is turned on and the relay 5 is driven.

Further, switches 4 for operating electrical components independently of the key switch 3 are connected to the collector of the transistor _Q3 , and wires are wired from the switches 4 to the multiple harness system 2 for connection to each electrical component. When one of the switches 4 to be operated is turned on, the transistor control circuit 6 is turned on, and power is supplied to the electrical component to be operated.

On the other hand, the comparator circuits A and B that sense abnormal voltage and the comparator circuit C that detects that the key switch 3 is turned on ST are connected to the resistor R ₄ and the Zener diode D 6 from the collector of the transistor Q ₁ of the transistor control circuit _6. A reference potential is set at the input terminal by . A divided input voltage is applied to the comparator circuit A by resistors R ₅ and R ₆ and to the comparator circuit B by resistors R ₈ and R ₉ , respectively. Therefore, in comparator circuit A, when the battery voltage drops abnormally, the output becomes Low and the operation of transistor _Q2 is turned off. Note that the resistor _R7 of the comparator circuit A functions to add hysteresis. Furthermore, in comparator circuit B, even if the battery voltage rises abnormally, the output becomes low and the operation of transistor _Q2 is turned off. Furthermore, the input terminal of the comparator circuit C is connected to the ST contact of the key switch 3 via a resistor _R10 .
When the voltage is turned on, the battery voltage divided by the resistors R ₁₀ and R ₁₁ is applied to the input terminal, so the output is
It becomes Low and turns off the operation of transistor _Q2 .
In this way, an abnormality in battery voltage is detected and the power supply to the multiple harness system is stopped. Moreover, it is possible to supply electric power in a concentrated manner when starting the engine.

In addition, the holding circuit for power supply consisting of transistors Q ₄ and Q ₅ is
The base side of Q ₄ is connected to the multiple harness system, while the collector of transistor Q ₅ is connected to the collector of said transistor Q ₃ . This circuit is driven by system control, and the transistor control circuit 6 is operated by the operation of transistors Q ₄ and Q ₅ . Therefore, even if various switches are turned off, only the electrical components that are desired to be operated are supplied with power from the battery 1 to be operated.

Next, a second embodiment will be described based on FIG. 2. Note that the description of the relay and the transistor control circuit for driving the relay, which are the same as those in the first embodiment, will be omitted.

In this embodiment, as shown in FIG. 2, the ACC (accessory) contacts of the key switch 3 are connected to diodes D ₅ , D ₆ , D ₇ , D ₈ and Zener diodes.
It is connected to the base side of the transistor Q ₆ via D ₉ , and the collector of the transistor Q ₆ is connected to the base of the transistor Q ₄ forming the transistor control circuit 6 via the resistor R ₁₂ . This transistor _Q6 is activated by the voltage of the battery 1 when the key switch 3 is turned on to the ACC contact. In this case, the base input of transistor Q ₆ is connected to diodes D ₅ , D ₆ , D ₇ , D ₈ and Zener diode D ₉
Set by. When the transistor Q ₆ operates, the base voltage of the transistor Q ₁ becomes Low and the transistor control circuit 6 is turned on.

The switches 4 other than the key switch 3 are connected to the base side of a transistor _Q7 , the emitter of the transistor _Q7 is connected to the battery ₁ via a diode D1, and the collector thereof is connected to a diode D via a diode _D10 . Connected to ₇ . When switch type 4 is turned on, the transistor
Q ₇ operates with its base set to Low. This operation of transistor Q ₇ causes the base voltage of transistor Q ₆ to go high, turning transistor Q ₆ on.

Furthermore, the ST (starter) contact of key switch 3 is connected to the base side of transistor Q 8 through diode D ₁₁ , and this base input is connected to the base side of transistor Q ₈ through diode D 11.
D ₁₂ , Zener diode D ₁₃ and base resistor
It is set by R ₁₄ and R ₁₅ . In this case, when key switch 3 is turned on to ST, the transistor
The base voltage of Q ₈ becomes High and transistor Q ₈
Since it is ON, the base voltage of transistor Q ₂ is
It becomes Low and the operation is turned off.

In addition, diode D ₁₂ and Zener diode D ₁₃ on the base side of transistor _Q 8 operate transistor Q ₈ and turn off transistor Q ₂ when the voltage of battery 1 becomes abnormally high.
It is something to do. On the other hand, if the voltage of battery 1 is abnormally low, the aforementioned diode D ₅ ,
The operation of the transistor Q 6 is turned off by lowering the base voltage of the transistor Q ₆ using D ₆ , D ₇ , D ₈ and the Zener diode D ₉ , and the transistor control circuit ₆ is accordingly turned off. It is.

Note that a hysteresis circuit is constituted by diodes D ₇ and D ₈ and a transistor Q ₉ whose base side is connected to the contact point of the relay 5. This is to prevent oscillation due to fluctuations in the voltage of the battery 1.

Furthermore, the transistor Q ₁₀ whose base side is connected to the multiple harness system and the diode D ₁₄ on its collector side constitute a holding circuit for power supply. When this transistor Q ₁₀ works,
The base voltage of transistor _Q7 becomes low and turns on.
Therefore, the transistor Q ₆ and the transistor control circuit 6 maintain their operation in the ON state. Therefore, even if the switch is turned off, the electrical components that should be kept in operation can be operated.

As described above with reference to specific circuits, according to the present invention, battery power can be supplied only when it is desired to operate the multiple harness system, making it possible to reduce the power consumption of the battery power supply. Become. In addition, the key switch is ST
(starter) or if the battery voltage is abnormal, the abnormality is detected and the battery power supply is stopped, preventing the multiple harness system from malfunctioning and protecting the electrical system. be able to.

[Brief explanation of the drawing]

FIGS. 1 and 2 relate to the present invention; FIG. 1 is a circuit diagram of a first embodiment, and FIG. 2 is a circuit diagram of a second embodiment. In the drawing, 1 is the battery, 2 is the multiple harness
system, 3 a key switch, 4 switches other than the key switch, 5 a relay, 6 a transistor control circuit for driving the relay, D ₁ to D ₄ , D ₇ , D ₈ ,
D ₁₀ , D ₁₁ , D ₁₂ , D ₁₄ are diodes, D ₆ , D ₉ , D ₁₃
is a Zener diode, Q ₁ to _{Q 10} are transistors, R ₁ to R ₁₄ are resistors, and A, B, and C are comparison circuits.

Claims (1)

[Claims for Utility Model Registration] A key switch having a first switch means for connecting a battery to a multiple harness system, an accessory contact and a starter contact that are contacts for driving accessories, even when the key switch is off. a second switch means for operating the multiple harness system; a holding circuit that is driven by system control even when various switches are off; a starter contact of the key switch being turned on; detection means for detecting an abnormal increase in the voltage of the battery or an abnormal decrease in the voltage of the battery; when the accessory contact of the key switch is selected and the second switch means is turned on; Alternatively, when the holding circuit is driven, it operates to close the first switch means;
A power supply for a multiple harness system, comprising a control circuit that stops operation and opens the first switch means when the detection means detects the closing of a starter contact or an abnormality in battery voltage.