JPS6038537B2 - Engine power display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine power display device used in automobiles or other devices, and in particular is designed to display whether a battery used to start the engine is in a charging state. .

In general, when starting an engine, not only for automobiles, the starter motor is rotated by borrowing electric power from a battery to start the engine.

After the engine starts, the engine drives the generator to self-sufficient the power necessary to keep the engine running, and excess power is supplied to the battery to charge it. The battery is charged when the engine is rotating faster than a predetermined speed, and the battery is in a discharged state when the engine is rotating slower than the predetermined speed. Furthermore, even if the engine is rotating far beyond a predetermined rotational speed, the battery may be in a discharged state when a large load is being operated. If this discharge state continues for a long time, the battery will become over-discharged and the engine will not be able to be started next time. Conventionally, a light bulb is connected between the battery and the voltage regulator of the generator, and the light bulb is turned off when the generator is generating electricity.

Therefore, the display only indicates whether or not the generator is generating electricity, but does not indicate the state of charging or discharging the battery.
Therefore, there is a risk that the battery will be left in a discharged state for a long time. SUMMARY OF THE INVENTION An object of the present invention is to provide an engine power display device that can display the charging and discharging status of a battery.

In this invention, a means for detecting the direction of current is provided between the battery and the generator, and the current direction detecting means detects the direction and lights one or the other of the pair of light emitting elements depending on the direction of the current. The charging/discharging status of the battery is displayed.

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

The figure shows one example of this.

In the figure, 1 indicates a battery. A starter motor 3 is connected to the battery 1 through a starter switch 2 . In addition, a load 4 such as a radio is connected. Reference numeral 5 indicates a generator, and the generated power of the generator 5 is supplied to the connection point between the battery 1 and the loads 3 and 4.

Reference numeral 6 indicates a contact of the voltage regulator, and when the generated voltage of the generator 5 reaches a predetermined value or more, the contact W is switched to the contact B.

Conventionally, a lamp (not particularly shown) is connected between the contact W and the battery 1, and when the generated voltage of the generator 5 reaches a predetermined value or more, the lamp goes out, and by turning off the lamp, the battery is actually charged. It is assumed that this is displayed.
In this invention, means for detecting the direction of current is provided between the battery 1 and the generator 5.

The means for detecting the direction of this current consists of a current detection resistor 7, resistor voltage dividers 8 and 9 connected to both ends of this resistor 7, and voltage dividers 8 and 9 that are connected to each other when the engine rotates. a transistor 11 connected to a common potential point when
It can be configured by a pair of comparators 1213 that compare the potentials at voltage division points A and B of the resistive voltage dividers 8 and 9. Light emitting elements 14 and 15 are connected to the output sides of comparators 12 and 13. This example shows a case where a light emitting diode is used as the light emitting element. The light emitting elements are connected in a forward direction from the outputs of the comparators 12 and 13 toward the common potential point.
For example, the four resistors constituting the resistive voltage dividers 8 and 9 may all have the same low resistance value.

When the resistance value of each resistor is set in this way, and the transistor 11 is suitable, the voltage dividing points A and B produce a voltage that is almost equal to the voltage of the battery 1. The divided voltage at the voltage dividing point A is supplied to the inverting input terminal of the comparator 12 and the non-inverting input terminal of the comparator 13, and the divided voltage at the voltage dividing point B is supplied to the non-inverting input terminal of the comparator 12 and the non-inverting input terminal of the comparator 13. Supplied to the inverting input terminal of The voltage of the battery 1 is supplied to the power terminals 16 and 17 of the comparators 12 and 13 through the starter switch 2. Further, the positive electrode voltage of the battery is applied to the base of the transistor 11 through a resistor 18. At the same time, the base of the transistor 1 is connected to the contact W of the voltage regulator 6 through the diode 19. With the above configuration, when the engine is not rotating and the starter switch 2 is on, the contact W of the voltage regulator 6 contacts the contact E and is connected to the common potential, so the transistor 11 is turned off. is maintained.

Therefore, no current flows through the voltage dividers 8 and 9, so the voltage division point A
The voltages at and B are equal to the voltages at both ends T and T2 of the current detection resistor 7. Therefore, since the voltages at the power supply terminals 16 and 17 of the comparators 12 and 13 are equal to the voltage at the input terminal, the comparators 12 and 13 do not operate and neither the light emitting elements 14 nor 15 light up. When the engine starts rotating, the voltage regulator 6
Contact W is connected to contact B to release the base of transistor 11 from the common potential.

Therefore, transistor 11 turns on and voltage dividers 8 and 9
The voltage at the voltage dividing points A and B becomes almost the same as the voltage of the battery 1. At this time, if the current flowing through the current detection resistor 7 is flowing from the battery 1 toward the load 4, the voltage at terminal T becomes higher than the voltage at T2. Therefore, since the voltage at the inverting input terminal of the input of the comparator 12 is high, its output becomes a low potential and the light emitting element 14 does not light up. On the other hand, since the voltage at the non-inverting input terminal of the comparator 13 becomes higher than the voltage at the inverting input terminal, its output becomes a high potential and the light emitting element 15 lights up. On the other hand, when current is flowing from the generator 5 to the battery 1, the voltage at the terminal T2 is higher than the voltage at T, so the voltage at the non-inverting input terminal of the comparator 12 is higher than the voltage at the inverting input terminal, so the comparison is made. The output of the device 12 becomes a high potential. Therefore, the light emitting element 14 lights up. On the other hand, since the voltage at the inverting input terminal of the comparator 13 is higher than the voltage at the non-inverting input terminal, the output of the comparator 13 becomes a low potential. Therefore, the light emitting diode 15 does not light up. Therefore, light emitting element 1
If 4 is green and 15 is red, when the green light emitting element is lit, it is displayed that the battery is being charged, and when the red light emitting element is lit, it is displayed that the battery is being discharged.

As explained above, according to the present invention, it is possible to display whether the battery 1 is being charged or discharged. Therefore, since the engine is rotating, it will definitely become battery 1.
The battery can be reliably charged without making a deliberate judgment that the battery is being charged.
can maintain a long lifespan. Note that in the above description, the light emitting element 1
Although light emitting diodes were used as 4 and 15, lamps may also be used.

When a lamp is used, a diode may be connected in series with the lamp so that the lamp is turned on only when the comparators 12 and 13 output logic H.

[Brief explanation of the drawing]

The figure is a connection diagram showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Battery, 5... Generator, 7... Resistor for current detection, 8, 9... Voltage divider, 12, 13... Comparator for detecting the direction of current, 14 , 15... Light emitting element.

Claims (1)

[Claims] 1. In an engine power supply device that includes a battery and a generator and is configured to supply charging current from the generator to the battery when the engine rotates above a predetermined speed, there is a gap between the battery and the generator. A power supply display device for an engine, comprising a pair of comparators that detect the direction of current flowing through connected current detection elements, and a light emitting element whose lighting is controlled by the detection output of the comparator.