JPS6242479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum cleaner in which a plurality of light emitting elements blink in response to input power to an electric blower.

In the conventional display circuit of this type of vacuum cleaner, as shown in FIG. A comparison potential 103 is connected to the terminal. light emitting diode 10
4 and 105 are connected in series and connected to both ends of the DC power supply, and the output terminal of the voltage comparator 100 is connected to the connection point of the light emitting diodes 104 and 105.

Here, when the comparison potential 103 is higher than the reference potential, that is, when the input potential of the inverting terminal is higher than the input potential of the non-inverting terminal, the voltage comparator 103
Although the output becomes a low potential, due to the characteristics of the voltage comparator 100, the voltage value is not completely zero and a voltage of 0.7 to 1V is generated. Therefore, the current that completely flows through the light emitting diode 104 does not flow into the output terminal of the voltage comparator 100, and a portion of the current flows through the light emitting diode 105.
There was a drawback that the light flowing through the light caused the light emitting diode 105, which was not supposed to be lit, to be lit.

The present invention eliminates these conventional drawbacks, and embodiments thereof will be described below with reference to the accompanying drawings.

First, Figure 1 shows the main configuration of a vacuum cleaner.
is the main case of the vacuum cleaner, 2 is the filter,
An electric blower 3 is provided behind it. 4 is a hose, and 5 is a connecting pipe that connects the main body case 1 and the hose 4. The air and dust sucked through the hose 4 are separated by a filter 2, and the air is discharged from an exhaust port 6. 7 is an air volume sensor provided between the front of the electric blower 3 and the filter 2.

Further, the vacuum cleaner of the present invention is provided with an electric blower 3 and an input power display circuit section 8, which will be described later, and which lights up in response to an input to the electric blower 3.

Next, in FIG. 2, a phase control circuit 9 is connected in series with the electric blower 3. Phase control circuit 9
Detects a signal from the airflow sensor 7 and controls the input power of the electric blower 3 to maintain a constant airflow.

In addition, a diode 1 is connected to the power supply side of the electric blower 3.
0, a resistor 11, and a capacitor 12. A plurality of light emitting diodes 24 to 28 are connected to the DC power source via a resistor 29.
An input power display section 8 consisting of a series connection of a resistor 13 and a resistor 13 is connected. This light emitting diode 24~
The output terminals of voltage comparators 14 to 17 are connected to the connection point 28, respectively.
Connect the DC power supply to the input side of 4 to 17 with resistors 18 to 21.
A diode 2 connected to the connection point between the reference voltage divided by the electric blower 3 and the phase control circuit 9
2, resistor 23, and resistor 30, capacitor 31
It is input to compare the voltage created by the series circuit.

When the conduction phase angle of the current flowing through the electric blower 3 is small and the input power is low, the comparison potential at the connection point between the resistor 23, resistor 30, and capacitor 31 is equal to resistor 1.
It becomes higher than the reference potential composed of 8 to 21. As a result, the outputs of the voltage comparators 14 to 17 become low potential, and since a voltage is applied across only the light emitting diode 24, current flows into the output terminal of the voltage comparator 14 through the diode 10, the resistor 29, and the light emitting diode 24, and lights up. However, the light emitting diode 25~2
8 does not light up because the voltage at both ends becomes zero. However, as the input power of the electric blower 3 increases, the comparison potentials of the input terminals of the voltage comparators 14 to 17 will fall below the reference potential determined by the resistors 18 to 21, so the output of the voltage comparators will be 14. The potential goes from low to high in order. For example, comparator 14, 15
If is a high potential and 16, 17 is still a low potential, current flows into the output terminal of the voltage comparator 16 through the light emitting diodes 24, 25, 26, and the light emitting diodes 24, 25, 26 light up, but 27, 2
8 is still short-circuited with zero voltage at both ends, so it does not light up.

In this way, as the input power supplied to the electric blower increases, the DC power supply voltage created by the diode 22, resistor 23, resistor 30, and capacitor 31 decreases, and this potential is applied to the resistors 18 to 21.
As the output potential of the voltage comparators 14 to 17 becomes lower than the reference potential created by , the output potential of the voltage comparators 14 to 17 becomes a high potential in order from 14, and the light emitting diodes are turned on in order from 21.

However, in reality, the output potential of the voltage comparator is not completely zero, and the voltage remains between 0.7 and 1V, so a small amount of current flows through the light emitting diode, which is not lit, and the light is lit. Therefore, by inserting the resistor 13, it is possible to suppress the current flowing through the light emitting diode that is not lit, and it is possible to make it completely unlit.

Although a light emitting diode is used as the display element in this embodiment, it goes without saying that a lamp, neon lamp, etc. may also be used.

As described above, according to the present invention, it is possible to reliably turn on and off the light emitting element, and thereby it is possible to accurately display information according to the input power of the electric blower, and its practical value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a vacuum cleaner showing an embodiment of the present invention, FIG. 2 is a circuit diagram, and FIG. 3 is a conventional display circuit diagram. 3...Electric blower, 8...Input power display circuit,
9... Phase control circuit, 13... Resistor, 14-17
... Voltage comparator, 24-28 ... Light emitting element (light emitting diode).

Claims (1)

[Claims] 1. It has a phase control circuit that is connected in series with an AC power source together with an electric blower, and an input power display circuit that displays according to the input power of the electric blower, and the input power display circuit has a plurality of light emitting elements connected in series. An output terminal of a voltage comparator is connected to the connecting portion of each of these light emitting elements, and a resistor is further connected between the termination of the light emitting elements connected in series and a power source. Machine.