JPH01311835A - Power supply controller - Google Patents

Abstract

PURPOSE:To prevent the lowering of battery voltage by temporarily limiting a power supply to a load circuit from a battery when battery voltage and the number of revolution of an engine attain set values or less. CONSTITUTION:A control circuit 6 normally transmits a signal turning a switch circuit 3 ON in order to supply a load circuit 2 with a power supply from a battery 1. The control circuit 6 sends an OFF signal to the switch circuit 3 by a signal conductor 10 in order to temporarily limit a power supply to the load circuit 2 until battery voltage and the number of revolution of an engine are returned to specified values or more when it is judged that the state in which the battery voltage and the number of revolution of the engine attain the specified value or less is continued for a fixed sec or more. Accordingly, the lowering of battery voltage is prevented, the possibility of the stoppage of the engine due to the lowering of battery voltage is removed, and the status in which the reduction of the capacity of the battery makes it difficult to start the engine can be obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit that supplies power from a battery to a load circuit, and more particularly to a circuit that monitors the state of charge of a battery and controls the power supply to the load circuit.

[Conventional technology]

Conventionally, this type of circuit that supplies power from the battery to the load circuit is connected directly from the battery to the load circuit as shown in Figure 4, so even if the battery voltage drops, the power is not supplied to the load circuit. There was no restriction unless the power to the load circuit was turned off with a switch.

[Problem to be solved by the invention]

The above-mentioned conventional circuit that directly supplies power from the battery to the load circuit does not control the power supply from the battery, so the electromotive force of the battery decreases after continuous use of the air conditioner during traffic jams in the summer, or in the winter. When the current supply capacity is significantly reduced, the battery cannot be charged in time, and there is a risk that the engine will stop due to a sudden drop in engine speed, such as when stopping with the brakes. In such a case, there is a drawback that restarting the engine becomes extremely difficult.

[Differences between the invention and the prior art]

In contrast to the above-described conventional circuit that directly supplies power from the battery to the load circuit, the present invention temporarily stops power supply to the load circuit when the battery voltage signal and engine rotation speed signal become below preset values. The difference is that it has a function that can be restricted to.

[Means to solve the problem]

The power supply control device of the present invention has a sensor output signal for detecting battery voltage and a sensor output signal for detecting engine speed connected to a control circuit, and receives the signal from the control circuit to supply power from the battery to the load circuit. Turn supply on/
It has a switch circuit that turns it off.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a basic block diagram of one embodiment of the present invention. A battery 1 is a power source for supplying power to a load circuit 2, and is connected via a switch circuit 3. Power line 4
is a power line that inputs the battery 1 to the switch circuit 3. The battery voltage detection sensor 5 is a sensor that detects the voltage of the battery, and inputs a battery voltage signal to the control circuit 6. The signal line 7 is a signal line for inputting a signal from the battery voltage detection sensor 5 to the control circuit 6.

The engine rotation speed detection sensor 8 is a sensor that detects the engine rotation speed, and inputs an engine rotation speed signal to the control circuit 6. The signal line 9 is the engine rotation speed detection sensor 8
This is a signal line that inputs signals from the control circuit 6 to the control circuit 6. The control circuit 6 is a control circuit that outputs an on/off signal to the switch circuit 3 when a certain condition is satisfied based on the battery voltage signal and the engine rotation speed signal. The signal line 10 is the control circuit 6
This is a signal line that sends on/off signals from the switch circuit 3 to the switch circuit 3. The switch circuit 3 is a circuit that turns on/off the power supply from the battery 1 to the load circuit 2 based on an on/off signal from the control circuit 6. The power line 11 is a power line that supplies power from the switch circuit 3 to the load circuit 2. The load circuit 2 is a load circuit that receives power supply from the battery 1, such as an air conditioner or a radio.

Next, the operation of the power supply control device of the present invention will be explained.

This embodiment limits the power supply from the battery to the load circuit when the battery voltage is below 8 [V] and the engine speed is below 1000 (r, p, m:) for more than 1 second. Battery voltage is 10[V:11
This is an embodiment in which power is supplied to the load circuit again when the engine speed reaches 1500 Cr, p, m] or more.

The battery 1 supplies power for operating the load circuit 2 via the switch circuit 3 via the power lines 4 and 11.

The battery voltage detection sensor 5 constantly detects the battery voltage and constantly sends a battery voltage signal to the control circuit 6 via the signal line 7. The engine rotation speed detection sensor 8 constantly detects the engine rotation speed, and constantly sends an engine rotation speed signal to the control circuit 6 via a signal line 9. The control circuit 6 normally sends a signal to turn on the switch circuit 3 in order to supply power from the battery 1 to the load circuit 2, and when the battery voltage is 8 [V] or less and the engine speed is lowered according to the battery voltage signal and the engine speed signal. When it is determined that the condition below 1000Cr, p, m:l has continued for more than 1 second, the battery voltage is 10[: VD or above and the engine speed], 500
Signal line 1 is connected to switch circuit 3 in order to temporarily limit the power supply to load circuit 2 until [r, p, m:] or more.
0 sends an off signal. The switch circuit 3 turns on/off the power supply from the battery 1 to the load circuit 2 in response to an on/off signal from the control circuit 6, and when turned on, supplies power to the load circuit 2 through the power line 11.

FIG. 2 is an operation flowchart of the control circuit 6.

FIG. 3 is a block diagram of a second embodiment of the present invention.

Power supply voltage 1, load circuit 2, switch circuit 3, power line 4,
11, battery voltage detection sensor 5, control circuit 6, signal lines 7, 9. No, engine speed detection sensor 8 is Example 1
It is similar to The display device 12 is a device that simultaneously displays when the power supply to the load circuit 2 is restricted, and the signal line 13 is a signal line that sends a display signal from the control circuit 6 to the display device 12. .

Next, the operation of this embodiment will be explained.

The operations of the battery 1, load circuit 2, switch circuit 3, battery detection sensor 5, control circuit 6, and engine speed detection sensor 8 are the same as in the first embodiment. The display device 12 receives a signal from the control circuit 6 via the signal line 13 at the same time when the control circuit 6 sends a signal to the switch circuit 3 to turn on/off the power supply to the load circuit 2, and the power is supplied to the load circuit 2. When it is present, it indicates that the battery is sufficiently charged, and when power is not being supplied to the load circuit 2, it is indicated that the power supply to the load circuit is being restricted by the power supply control device.

Since this embodiment has a display device, the state of charge of the battery can be known. In addition, when the power supply to load circuit 2 is restricted, the function of load circuit 2 stops because load circuit 2
There is an advantage in that it can be determined that the function has stopped because the power supply is restricted by the power supply control device, rather than due to a failure.

〔Effect of the invention〕

As explained above, the present invention prevents a drop in battery voltage by adding a device for controlling power supply to a load circuit in a circuit that supplies power from a battery to a load circuit in an automobile electrical system. This has the effect of eliminating the fear of the engine stopping due to a drop in voltage, and making it possible to avoid situations where it becomes difficult to start the engine due to a drop in battery capacity.

[Brief explanation of the drawing]

FIG. 1 is a basic block diagram of the first embodiment of the power supply control device of the present invention, FIG. 2 is an operation flowchart of the control circuit of the first embodiment, and FIG. 3 is the power supply control device with display device of the second embodiment. Block Diagram FIG. 4 is a block diagram of a conventional example. 1...Battery, 2...Load circuit,
3...switch, circuit, 4,11.14...
...Power supply line, 5...Battery voltage detection sensor, 6...Control circuit, 7゜9.10.13...
... Signal line, 8 ... Engine rotation speed detection sensor, 12 ... Display device. Agent Patent Attorney Otowara Uchihara, 3 Figures

Claims (1)

[Claims] A circuit for supplying power from a battery to a load circuit in an automobile electronic device has a sensor for detecting battery voltage and a sensor for detecting engine speed, and the battery voltage signal and engine speed signal from the sensor are set in advance. 1. A power supply control device that temporarily limits power supply to a load circuit that does not affect the running of a vehicle when the voltage falls below a certain value.