JPH04189326A - Display circuit for vacuum cleaner - Google Patents

Abstract

PURPOSE:To appropriately display the change time of a dust bag by one piece of display element irrespective of whether suction force is large or small by providing a second pressure switch in a suction path and connecting it in parallel to a pressure switch, and connecting a switching element and a second pressure switch in series. CONSTITUTION:When a motor 12 is in the maximum rotation, dust collects fully in a dust bag, a pressure switch 17 installed in an air passage is turned on, an LED 18 is lighted, and a change time of the dust bag is informed. Subsequently, when the motor is subjected to phase control by a phase control circuit 14, and the speed of revolution of the motor 12 becomes small, a potential difference is generated across a triode AC switch 13 and a voltage rectified by a diode 22 and a second power source resistance 23 is stabilized by a Zener diode 24 and a capacitor 25, and a bias is applied to a base of a transistor 28 by resistance 26, 27. In such a state, when dust collects fully in the dust bag, even if pressure in the air passage does not reach working pressure of the pressure switch 17, a second pressure switch 29 and the transistor 28 are turned on, the LED 18 is lighted, and the change time of the dust bag can be informed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a display circuit for a vacuum cleaner having a function of varying the rotational speed of a motor.

2. Description of the Related Art Conventional display circuits for vacuum cleaners of this type generally have a configuration as shown in FIG. As shown in the figure, the rotation speed of a motor 2 connected to a power source 1 is controlled by a phase control circuit 4 connected to a triac 3, and the suction force of the vacuum cleaner changes. When dust accumulates in the garbage bag inside the vacuum cleaner, the pressure switch 5 installed in the air suction flow path turns ON, and the lamp 6 lights up, reminding the vacuum cleaner user that it is time to replace the garbage bag. It was to inform.

Problems to be Solved by the Invention In such conventional vacuum cleaner display circuits, the pressure switch is set to operate when the vacuum cleaner's suction power is at its maximum and the garbage bag is full of dust. Therefore, there was a big problem that if the vacuum cleaner was used in a place where the suction power was low, the garbage bag would not be displayed even if it was full of dust.

The present invention solves the above problem, and aims to appropriately display the time to replace the garbage bag with a single display element, regardless of whether the suction force of the vacuum cleaner is large or small.

Means for Solving the Problems In order to achieve the above object, the display circuit of the vacuum cleaner of the present invention includes a dust collection motor built into the main body,
A pressure switch provided in a suction path to be depressurized by the motor and operated by negative pressure, a display element lit by the pressure switch, and a control circuit for controlling the rotation speed of the motor, the control circuit having a phase It has a triac that performs control and a switching element operated by a potential difference between both ends thereof, and a second pressure switch is provided in the suction path and connected in parallel with the pressure switch, and the switching element and the second pressure switch are provided in the suction path and connected in parallel with the pressure switch. are connected in series.

Effect In the above-described configuration, the second pressure switch is provided in the suction path and connected in parallel with the pressure switch, and the switching element and the second pressure switch are connected in series.
When the suction force is large, the display element is turned on by the pressure switch, and when the suction force is small, the display element is turned on by the switching element and the second pressure switch.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, a motor 12 and a triac 13 are connected in series to a power source 11. A phase control circuit 14 is connected to the gate of the triac 13, and this circuit controls the rotation speed of the motor.

Further, the power source 11 includes a first diode 15, a first power source resistor 16, a first pressure switch 17, an LED 18 . resistance 1
9 are connected in series. Resistance 19. LED
18. Zener diode 2 in parallel with pressure switch 17
0. A capacitor 21 is connected.

Also, at the connection point between the motor 12 and the triac 13,
The anode of the diode 22 is connected, the cathode is connected to the second power supply resistor 23, and the Zener diode 24. The capacitor 25 constitutes a DC power supply circuit. Resistor 26.2 connected to this DC power supply circuit
7 is connected to the base of a transistor 28, and the collector of the transistor 28 is connected to a second pressure switch 29.
are connected in series. This transistor 28° pressure switch 29 is connected in parallel with the pressure switch 17. Here, the pressure switch 17 and the second pressure switch 2
The operating pressure setting with 9 is (pressure switch)>(second pressure switch).

To explain the operation in the above configuration, first, motor 1
When 2 is making maximum rotation, triac 13
Since the potential difference between is approximately Ov, the Zener diode 2
4 is also Ov, the transistor 28 is OFF, and the LED 18 is not turned on by the second pressure switch 29. At this point, dust accumulates in the garbage bag, and the pressure inside the air flow path is reduced by the pressure switch 17 installed in the air flow path.
When the operating pressure of L is reached, the pressure switch 17 is turned on and L
ED18 lights up to notify the user that it is time to replace the garbage bag. Next, the phase of the motor is controlled by the phase control circuit 14, and when the rotational speed of the motor 12 becomes small, a potential difference is generated between both ends of the triac 13, and the diode 22,
The voltage rectified by the second power supply resistor 23 is applied to the Zener diode 24 . stabilized by capacitor 25,
Resistors 26 and 27 bias the base of transistor 28. Here, if the pressure in the air flow path is set to reach the operating pressure of the second pressure switch 29 even if it does not reach the operating pressure of the pressure switch 17, once the dust has accumulated in the garbage bag. , second pressure switch 29
is turned ON, the transistor 28 is also turned ON, and the LED 18 lights up, making it possible to inform the user that it is time to replace the garbage bag.

As described above, according to the present invention, it is possible to know at a glance when it is time to replace the garbage bag, regardless of the rotational speed of the motor 2.

Next, another embodiment will be described with reference to FIG. In FIG. 2, power supply 11. Motor 12゜Triac 1
The 32 phase control circuit 14 has the same configuration as the first embodiment.

The voltage rectified by the first diode 15 and the first power supply resistor 16 is stabilized by the Zener diode 20, and the voltage is stabilized by the first pressure switch 17. LED18. A resistor 19 is connected in series.

Further, an anode of a diode 22 is connected to the connection point between the motor 12 and the triac 13, and a resistor 23 is connected to the cathode. Zener diodes 24 are connected in series. A resistor 26 in parallel with the Zener diode 24.
27 is connected, and the base of a transistor 28 is connected between this resistor. A second pressure switch 29 is connected to the collector of the transistor 28, and the pressure switch 1
7 and constitutes a parallel circuit.

To explain the operation of the circuit configured as described above, first, when the motor 12 is rotating at maximum speed, no voltage is generated across the Zener diode 24, so the transistor 28 does not operate.

If the first pressure switch 17 is set to turn on when the garbage bag is full of dust, the first diode 15, first resistor 16, resistor 19° LED 18. Current flows through the pressure switch 17 and the LED 18 lights up. Next, the phase of the motor 12 is controlled by the phase control circuit 14, and when the rotation speed is small, the triac 13
A voltage is generated across the Zener diode 24, and a constant voltage is generated across the Zener diode 24. Here, when no dust is accumulated in the garbage bag, both the first pressure switch 17 and the second pressure switch 29 are OFF, so the LED does not light up. Next, when the garbage bag is full of dust, a second
Pressure switch 29 is turned on, and diode 15. Resistance 16, 19°LED 18. Pressure switch 29.1-
A current flows through the transistor 28 and the LED 18 lights up.

As described above, according to the present invention, it is possible to appropriately indicate the time to replace the garbage bag using a single LED, regardless of the rotation speed of the motor.

Figure 3 shows the main body 41 of the vacuum cleaner, the hose 422, the hand handle 43. Extension tube 44. The floor nozzle 45 constitutes a vacuum cleaner.

Further, the LED 18 is attached to the main body 41 and mounted so as to be easily visible from the outside. As described above, according to the present invention, since the phase control circuit 14 is usually mounted inside the handle 43, the circuit of the present invention has an LED 18 on the main body 41.
Since the configuration in which the display section is provided can be easily performed, the configuration of the display section can be simplified.

Effects of the Invention As is clear from the description of the embodiments above, in the display circuit for a vacuum cleaner of the present invention, the control circuit includes a triac that performs phase control and a switching element that operates based on the potential difference between the two ends of the triac. By providing a second pressure switch in the path and connecting it in parallel with the pressure switch, and connecting the switching element and the second pressure switch in series, a single display can be displayed regardless of the magnitude of the suction force. The element can appropriately indicate when to replace the garbage bag.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a display circuit of a vacuum cleaner according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a display circuit of a vacuum cleaner according to another embodiment of the present invention, and FIG. 3 is a circuit diagram showing a display circuit of a vacuum cleaner according to another embodiment of the present invention. FIG. 4 is a circuit diagram showing the display circuit of a conventional vacuum cleaner. 12... Motor, 13... Triac, 17... Pressure switch, 18...
-LED, 28...transistor (switching element), 29...second pressure switch. Name of agent: Patent attorney Haruaki Ogata and 2 others Mi 1 Hakuku 1
)) False image BeQha 1st) IJ-L appearance” engineering book

Claims (1)

[Claims] A dust collection motor built into the main body, a pressure switch installed in the suction path that is depressurized by this motor and activated by negative pressure, a display element lit by this pressure switch, and the rotation speed of the motor. The control circuit includes a triac that performs phase control and a switching element operated by a potential difference between the two ends of the triac, and a second pressure switch provided in the suction path in parallel with the pressure switch. A display circuit for a vacuum cleaner, which is connected to the switching element and a second pressure switch in series.