JPS61294529A - Electronic controller - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a control circuit containing a relay contact by securing a low power mode with application of the 2nd constant voltage circuit at each part excluding a central processing unit and a read/write memory to deliver and cut off the constant voltage. CONSTITUTION:A battery power supply 12 of an automobile is connected to a voltage controller 13 of an electronic controller 11. Thus a current controlled to a fixed level of voltage is always supplied to a central processing unit CPU15 and a read/write memory RAM16 via the 1st constant voltage circuit 17. The CPU15 contains an interruption terminal (b), an input terminal (c) for low power mode and an output terminal (i) in addition to a power supply terminal (a). While the RAM16 contains an input terminal (e) for low power mode and is connected with a low power circuit 27. Furthermore a ROM31, an input/output device 32, an A/D converter 33, etc. are connected to the 2nd constant voltage circuit 30 branched out of the circuit 17. Then the circuit 30 is connected to a control circuit 35 having a contact 34 of a relay 23. Thus the CPU15 turns off the relay 23 when a main switch 18 is kept off. Then a low power mode is secured with an electronic controller.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic control device equipped with a read/write memory, and more particularly to an electronic control device capable of reducing power consumption supplied to the memory when the power switch is turned off. It is applied to electronic control devices used for controlling automatic heavy engineering/etc.

For example, in addition to the air-fuel ratio, cars also have ignition timing.

Control history of engines/rotational speeds, transmissions, etc. is often equipped with an electronic control device (microcomputer) to display various information. This electronic control device includes an input/output device for inputting and outputting signals, a storage device consisting of read-only memory and read/write memory,
The main part is a central processing unit that calculates output signals based on the data and programs in the read-only memory and the human input signals from the human output interface, and the read/write memory temporarily stores the human output data and the calculation data. It has an overlapping role as a part that not only reads out data as needed but also provides a learning function to the system.

Conventionally, even when a car's ignition switch is turned off, it is necessary to apply voltage to both read and write memory to prevent memory loss, and this part is directly connected to a power source separately from other parts. . Therefore, there is a problem in that the power consumption is constant regardless of whether the vehicle is running or stopped, and the power source is wasted.

Furthermore, as shown in FIG. 3, some electronic control devices used in automobiles and other applications use an auxiliary power source 2 such as a dry battery in addition to a regular power source 1 consisting of a battery. The one in Figure 3 is read/write memory (RAM) 3
and the central processing unit @ (CPU) 4 and the current from the regular power supply 1 regulated by the voltage regulator 5 or from the auxiliary power supply 2! ! current is supplied.

When the main switch 6 is turned on and the relay 7 is turned on, the input/output device (10)8. The read-only memory (ROM) 9 and the converter (/D) 10 and other parts are supplied with current from a regular power supply l, while the read/write memory 3 and the central processing unit 4 are supplied with high voltage from two power supplies 1.2. Current is supplied from the When the main switch 6 is turned off, the current to the input/output device 8 is cut off, and the read/write memory 3 and the central processing unit 4 are supplied with current from the auxiliary power supply 2 to maintain their memories. Therefore, there is a problem that if there is a potential difference between points A and B in FIG. 3, it may cause malfunction or damage to the integrated circuit in each part.

The present invention solves the above problems by having a circuit configuration that does not use an auxiliary power supply (therefore, there is no need to worry about potential differences occurring between each part) and can reduce power consumption when the main switch is turned off. The electronic control device 7 is provided with a first floating voltage circuit which is connected to each power terminal of the central processing unit and the read/write memory and which outputs a constant voltage at all times, and each part other than the above mentioned above. a second constant voltage circuit that outputs the same constant voltage; and a relay contact that is turned on and off in response to a voltage signal applied to the output terminal of the central processing unit. It is characterized by comprising a control circuit that opens and closes the main switch, and a low power circuit that outputs a voltage to the input terminal of the read/write memory to enter a low power mode when the main switch is turned off.

Example Examples of the present invention will be described based on the drawings.

In FIG. 1, a power source 12 consisting of a battery mounted on an automobile is connected to a voltage regulator 13 of an electronic control unit 11 surrounded by a dashed line by a main power line 14, and 1! The current adjusted to a constant voltage by the pressure regulator 13 is sent to the central processing unit (CPU) 15 and the read/write memory (RAM).
) The first constant voltage circuit 1 is connected to each of the 16 power supply terminals a and d.
7 and is constantly supplied. , FIG. 2 (A, D) shows when the two power supply terminals a and d are connected to the power supply 12 (T1
) - is a diagram showing that a constant voltage is output to these.

In addition to the power supply terminal a, the central processing unit 15 has an interrupt terminal
The input terminal C1 for low power mode is connected to the output terminal 11, branched from the main power line 14, and connected from the ignition switch to the null main switch 7 +18e amplifier circuit 19. Clamp times%20
An actuating circuit 21 having the following in order is connected to the input terminal C, and a driving circuit 22 branched from between the amplifier circuit 19 and the clamp circuit 20 is connected to the interrupt terminal S, and further branched from the main power line 14. Coil 24 of relay 23
An output circuit 26 having a transistor 25 and a transistor 25 is connected to the output terminal 1 .

In addition to the power supply terminal d, the read/write memo 1716 has an input terminal e for low power mode.

A low power circuit 27 branched from the amplifier circuit 19 is connected to this input terminal e.

A second constant voltage circuit 30 branched from the first constant voltage circuit 17 and having an operational amplifier 28 and a transistor 29 is a read-only memory (ROM) 31. Human output device fl (I/1)
) 32 and the converter (%) 33 and a control circuit 35 which is connected to the power terminals f, g, and b of other peripheral devices, has a contact 34 of the relay 23, and is branched from the main power line 14.
is connected to the emitter side of the transistor 29.

When main switch 1B' is turned on (T2), operation Ej path 2
1. A constant voltage as shown in Fig. 2 (a) is outputted to the input terminal C2 interrupt terminal via the drive circuit 22, and the voltage of the low power circuit 27 becomes zero, and the voltage shown in Fig. 2 is output to the input terminal e. No voltage is output to the central processing unit 1.
5 and the read/write memory 16 are in the normal operating mode, and the signal at the output terminal +1 is set to a high level as shown in FIG.

Therefore, the transistor 29 operates to close the second constant voltage circuit 30, and the output device 32. A constant voltage as shown in FIG. 2 (F, G, H) is also output to the converter 33 and the like.

Through the above operations, each part of the electronic control device 11 is outputted with the same voltage, thereby entering the normal operation mode, and performs control and the like.

When the main switch 18 is turned off (T3), the voltage at the first interrupt terminal becomes zero, and the central processing unit 15 enters interrupt processing and sets the voltage at the output terminal I to zero, turning off the relay 23, and setting the second constant voltage. The circuit 30 is cut off and the power supply voltage of the parts other than the central processing unit 15 and the read/write memory 16 is set to zero. When the interrupt processing is finished (T4), the voltage at the input terminal C becomes zero, and when the main switch 18 is turned off (T3), the first constant voltage circuit 17 is connected to the K input terminal e.
voltage is applied, and from then on, the central processing unit Is and the read/write memo 1716 enter the low power mode.

The next time the main switch 18 is turned on, the normal operation mode is established by repeating the above steps.

According to the present invention, a control circuit having a relay contact that is turned on and off by a voltage signal applied to an output terminal of a central processing unit in response to a main switch is used to control each part other than the central processing unit and read/write memory. A second constant voltage circuit that outputs or cuts off the same constant voltage as the two parts is opened and closed, and a voltage is output to the low power mode input terminal of the read/write memory when the main switch is turned off, and the low power mode is activated. As a result, power consumption is reduced compared to conventional systems in which the read/write memory is directly connected to a power source or an auxiliary power source is used, and the battery installed in the vehicle is not wasted.

There is no need to worry about malfunctions or damage to the integrated circuit. Further, the operation is simple because switching between the normal operation mode and the low power mode is performed by a single operation of the main switch.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a timing chart of signal voltages at each terminal, and FIG. 3 is a block diagram of a conventional example. 11...Electronic control unit, 12...Power supply, 15...Central processing unit, 16...Read/write memory. 17...First constant voltage circuit, 18...
main switch. 21... Operating circuit, 22... Drive circuit, 23... Relay, 26... Output circuit, 27... Low power circuit. 30... Second constant voltage circuit, 34...
Contact, 35... Control circuit, a, d...
・'tIL source terminal, e... Input terminal, l...
...Output terminal. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A first constant voltage circuit that is connected to each power supply terminal of the central processing unit and the read/write memory and outputs a constant voltage at all times, and a second constant voltage circuit that outputs the same constant voltage as the above to each part other than the above. a control circuit that opens and closes the second constant voltage circuit, which has a relay contact that is turned on and off by a voltage signal applied to the output terminal of the central processing unit in response to the main switch; . A low power circuit that outputs a voltage to an input terminal of a read/write memory to enter a low power mode when the main switch is turned off.