JPS6327769A - Apparatus for confirming operation of electric circuit - Google Patents

Abstract

PURPOSE:To reduce not only the number of sensors for detecting abnormality but also a mount space, by providing a current detection sensor to a power source bus and collating the detection result of said sensor with a control signal at the point of time of detection. CONSTITUTION:A control circuit 9 sends out a signal driving the electric circuit of each system through a drive circuit 20 and the transistor corresponding to said signal among transistors 17a-17d is turned ON and the electric system connected to the transistor turned ON is driven. The current flowing to the electric system driven flows to a current divider 18 where a current value is detected to supply a current signal to a detection circuit 21. The signal supplied to the drive circuit 20 is supplied to the detection circuit 21 other than said current value. The detection circuit 21 discriminates the electric system showing abnormality on the basis of two kinds of signals supplied. Since a current of other control item is removed from a discrimination object, when discrimination items are successively changed, all of the items are discriminated accurately.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electrical circuit operation confirmation device for confirming the operation of each system in a vehicle having multiple electrical systems, such as an automobile electrical system. It is.

[Conventional technology]

Generally, the electrical system of a vehicle is composed of many systems as shown in FIG. In Fig. 2, 1 is a steering gear box, 2 is a steering wheel, 3 is a steering sensor, 4 is a motor with an oil pump inside, 5 is a battery, 6 is an ignition switch, and 7
1 is an engine, 8 is a generator, 9 is a control circuit, 10 is a switch for changing control characteristics, 11 is an oil tank, 12 is a temperature sensor that detects the temperature of the oil, 13 is a heater that heats the oil, and 14 is a temperature sensor 12 is an energizing circuit that energizes the heater 13 based on an output signal, 15 is a lamp, and 1B is a solenoid.

In the apparatus configured as described above, the operation of each electrical system is checked by providing a sensor in the control circuit 9 to detect the current supplied to each electrical system.

[Problem that the invention seeks to solve]

However, since such a conventional device requires a large number of stages of sensors, it has many problems such as installation space, cost, and an increase in the number of wires.

[Means for solving problems]

In order to solve this problem, the present invention provides a current detection terminal on the power supply bus.

[Effect]

The detected current is compared with the control items at that time to confirm operation.

〔Example〕

Figure 1 is a block diagram showing one embodiment of this invention.
, 17a to 17d are transistors, 18 is a shunt, 20
21 is a drive circuit, and 21 is a detection circuit. The control circuit 9 sends a signal to drive the electric circuit of each system via the drive circuit 20, so that one of the transistors 171 to 17d corresponding to the signal is turned on and connected to the turned on transistor. The electrical system is driven.

The current flowing through the driven electrical system flows to the shunt 18,
The detection circuit 21, in which the current value is detected and supplied to the detection circuit 21, is also supplied with a signal to be supplied to the drive circuit 20.

In this case, since the load current controls the control states of a plurality of electrical systems, there are many cases where there are differences in the load current. For example, the motor 4 has a rotation amount that changes depending on the amount of steering of the steering wheel 1, and the heater 13 is driven to maintain the oil temperature in the oil tank 11 above a predetermined value when the oil temperature drops. As a result, the load current becomes different.

When the signal detected by the shunt 18 is supplied to the detection circuit 21, the detection circuit 21 compares it with an internal reference value,
By determining whether a load current flows, it is possible to determine whether or not the operation of the electrical system is normal. However, many electrical systems have multiple sources, and some of them are supplied at the same time.

In this case, the current flowing through the shunt 18 is the sum of these values. However, it is not possible to determine which electrical system is abnormal only by comparing it with reference values.

Therefore, in the present invention, the signal supplied to the drive circuit 20 is also supplied to the detection circuit 21. Then, the detection circuit 21 receives the supplied 21! In this way, the current of other control items is excluded from the determination target, so if you change the determination items one after another, you can determine which electrical system is abnormal. done accurately. When an abnormality is detected, the detection circuit 21 sends back a signal to the control circuit 9 indicating that an abnormality has occurred.

As a result, the control circuit 9 operates to sequentially control each electrical system one by one, so that the detection circuit 21 can detect which system has an abnormality.

Next, the detection circuit will be explained. A determination as to whether the load current is abnormal is made by supplying the voltage from the shunt 18 to the comparator 34 and comparing it with a reference voltage created by the resistors 32 and 33. When an excessive current flows through the shunt 18, the input voltage of the comparator 34 exceeds the reference voltage, and 1" is sent to the control circuit as an output. Next, the control circuit 9 drives each electrical system in order. Start driving.

Here, the drive signal input terminal d of the detection circuit 21 has 1'1.
' is input. When, for example, the transistor 17a is activated by this drive signal, a load current corresponding to the load 4 flows through the shunt 18. The voltage of this load current phase is supplied to a comparator 25.28, which is connected to a resistor 23.24 and a resistor 26.2.
It is compared with the reference value determined in step 7 and sent to the AND circuit 2B. Therefore, the output of the AND circuit 29 becomes @1m only when the current value corresponds to the load 4. AND circuit 3
゜ outputs 11'' when both the output of the AND circuit 29 and the input signal of the terminal d become ``1''. This allows the control circuit 9 to determine whether the load 4 is normal or not. In the same way, other electrical systems can be discriminated and the abnormal electrical system can be known. Note that symbols 31a to 31d are abnormal system discrimination circuits, and 35 is an overcurrent detection circuit.

〔Effect of the invention〕

As explained above, this invention detects the current value of the power bus bar and compares the detection result with the control signal at that point. Since the space is reduced and the number of wires is reduced, the number of assembly steps is reduced and economical efficiency is improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing details of a detection circuit, and FIG. 3 is a block diagram showing a control system of an automobile. 18... shunt, 19 fist... φ control circuit, 20...
- Self-driving circuit, 21Φ-operation/detection circuit, 31... abnormal system discrimination circuit, 32... excessive current detection circuit.

Claims (1)

[Claims] When multiple electric circuits are controlled by control signals from a control circuit, an electric circuit operation check device that checks the operation of these electric circuits uses a current sensor that detects the current value of the power bus, and a current sensor that detects the current value of the power bus. 1. An operation confirmation device for an electric circuit, comprising a detection circuit that compares the obtained signal with the control signal at that time and detects that a control item is in a normal operating state.