JPH0512879Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a central alarm system that detects when the remaining amount of fuel, the pressure of engine lubricating oil, etc. have reached an abnormal level.

(Prior Art) Conventionally, for example, the one shown in FIG. 3 is known as a central warning system for automobiles and the like. For example, when the remaining fuel amount sensor 101 detects that the remaining amount of fuel has reached an abnormal level, an H level signal is output from the output terminal 104a of the input circuit 104 and is passed through the OR circuit 105 to the AND circuit 106. Enter. When this signal is input, the blinking signal output from the blinking circuit 107 is transmitted to the AND circuit 10.
6 is output from AND circuit 108 (holding circuit 3
(H level signal is always output from 07)
input to the base of switching transistor 301 through
flashes, and this flashing notifies the driver that the remaining amount of fuel has reached an abnormal level.

In addition, 102 is a lubricating oil pressure sensor that detects an abnormality in the pressure of lubricating oil, 103 is a cooling water temperature sensor that detects an abnormal temperature of cooling water, 305 and 306 are overcurrent detection circuits, 308 and 309 are holding circuits, 202,
203 is a warning light; 110 is a pseudo abnormal signal generation circuit that generates a pseudo signal to test whether the alarm device operates normally.

(Problem that the invention attempts to solve) However, the switching transistor 30
When 301a on the collector side of 1 is short-circuited to the power supply, an overcurrent flows through the transistor 301, this overcurrent is detected by the overcurrent detection circuit 304, and the output of the holding circuit 307 becomes L level, which As a result, the transistor 301 was turned off and the blinking of the warning light 201 immediately went out, so that the driver did not notice anything abnormal. If left as is, problems such as engine and vehicle failures such as overheating may occur if the abnormality is in the lubricating oil pressure or cooling water temperature.

Therefore, this invention was made in view of the above-mentioned circumstances, and is a centralized alarm system that, when a switching transistor is short-circuited, activates alarms corresponding to other switching transistors to notify the short-circuit accident. The purpose is to provide

(Means for solving the problem) In order to achieve the above object, the present invention provides a method for switching one of the switching transistors 301 to 303.
When an overcurrent detection circuit 304 provided corresponding to the switching transistor 301 detects that an overcurrent has flowed through the switching transistor 301, the output of the overcurrent detection circuit 304 controls the switching transistors 302 and 303 other than the switching transistor 301 through which the overcurrent has flowed to a closed state.

(Function) With the above configuration, when the overcurrent detection circuit 304 detects an overcurrent, the switching transistors 302 and 302 other than the switching transistor 301
303 is controlled to be in a closed state, and this control activates the alarm devices 202, 203 corresponding to the switching transistors 302, 303.

(Example) Hereinafter, an example of this invention will be described based on the drawings.

FIG. 1 is a circuit diagram of a centralized alarm system according to this invention.

The output terminals of each holding circuit 307-309 are connected to inverters 401-403 and diodes 404-4.
06 to the OR circuit 407.
The output terminal of this OR circuit 407 is connected to each OR circuit 10.
5, 105', 105''.

Components that are the same as those shown in FIG. 3 are designated by the same reference numerals, and therefore their description will be omitted.

Now, for example, when the remaining fuel amount sensor 101 detects that the remaining amount of fuel has reached an abnormal level, the switching transistor 301 is activated as in the conventional case.
is turned on and the warning light 201 blinks.

When the collector side 301a of the switching transistor 301 is short-circuited to the power supply, an overcurrent flows through the switching transistor 301, is detected by the overcurrent detection circuit 304, and an L level signal is output from the holding circuit 307. As a result, the switching transistor 301 is turned off, and the flashing of the warning light 201 disappears. On the other hand, holding circuit 3
The L level signal outputted from 07 is inverted by an inverter 401, becomes an H level signal, and is input to AND circuits 106', 106'' via OR circuits 407, 105', 105''. Then, a blinking signal is output from the AND circuits 106', 106'' and inputted to the bases of the switching transistors 302, 303 via the AND circuits 108', 108'', and the switching transistors 302, 303 are turned on to turn on the warning light 202. , 203 blinks. This blinking notifies the driver of the short circuit accident, and prevents conventional vehicle failures such as engine stalling and overheating.

In the above embodiment, all the warning lights corresponding to the switching transistors other than the short-circuited switching transistor are blinked, but at least one of them may be blinked.

FIG. 2 shows another embodiment in which the switching transistors 301 to 303 are PNP transistors.
It is composed of transistors.

(Effects of the invention) In short, this invention has the advantage that when a switching transistor is short-circuited, an alarm corresponding to a switching transistor other than this transistor is activated, so the driver is notified of the short-circuit accident, which is different from the conventional one. Vehicle accidents such as engine stalling and overheating can be prevented.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of a centralized alarm system according to the present invention, FIG. 2 is a circuit diagram of another embodiment, and FIG. 3 is a circuit diagram of a conventional centralized alarm system. 101...Remaining fuel amount sensor, 102...Lubrication oil pressure sensor, 103...Cooling water temperature sensor, 201~
203...Warning light, 301-303...Switching transistor, 304-306...Overcurrent detection circuit.

Claims (1)

[Scope of utility model registration request] connected in series to a plurality of alarm devices 201 to 203 centrally arranged corresponding to the plurality of sensors 101 to 103, and each of the plurality of sensors 101 to 1
A plurality of switching transistors 301 to 303, which are controlled to open and close according to the respective outputs of 03, control the power supply to the plurality of alarm devices 201 to 203, respectively, and also control the power supply to the plurality of switching transistors 301 to 303, respectively. When a current flows, the plurality of switching transistors 301-
The outputs of the plurality of overcurrent detection circuits 304 to 306 provided corresponding to the plurality of switching transistors 301 to 303 respectively control the plurality of switching transistors 301 to 303 so that overcurrent does not flow to the plurality of switching transistors 301 to 303. In a centralized alarm device controlled to be in an open state, when an overcurrent flows through any one of the plurality of switching transistors 301 to 303, the switching transistor 30
When detected by the overcurrent detection circuit 304 provided corresponding to 1, the overcurrent detection circuit 304
3. A centralized alarm device characterized in that switching transistors 302 and 303 other than the switching transistor 301 through which the overcurrent flowed are controlled to be in a closed state by the output of the above.