JPH0137943B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an electric blower input control circuit in a vacuum cleaner.

TECHNICAL BACKGROUND OF THE INVENTION AND THE PROBLEMS FIG. 1 shows the external appearance of a conventional vacuum cleaner, in which there is a removable dust collection case 2 in the front part of the main body case 1, and the hose difference between the dust collection case 2 and the A hose 4 is inserted into the inlet 3. An operation switch section 6 is provided at the hose proximal section 5.

FIG. 2 shows the circuit configuration. Basically, an electric blower 8 and a bidirectional thyristor 9 are connected in series to a 100 V AC power source 7 of AC 50/60 Hz. A protective resistor R ₁ and a capacitor C ₁ are connected in parallel to this bidirectional thyristor 9 .
Further, on the gate side of the bidirectional thyristor 9, a gate trigger circuit 11 mainly consisting of a characteristic variable negative resistance element PUT10 and a capacitor _C2 is provided.
This PUT10 is a dividing resistor connected to the gate side
Characterized by R ₆ and R ₇ , when a voltage determined by these resistances R ₆ and R ₇ is applied to the anode side,
It is something that turns on. Therefore, the AC power source 7 is connected to both ends of the resistors R ₆ and R ₇ via a diode through the resistor R ₁₀ .
Full-wave rectification with a rectifier circuit 12 consisting of D ₃ to _{D 6} , and resistance
A constant voltage made constant by a Zener diode ZD is applied via _R9 . On the other hand, PUT1
A capacitor C ₂ is connected to the anode of 0. Further, the cathode side of PUT 10 is connected to the gate of thyristor 13 via resistors R ₄ and R ₅ . This thyristor 13 is connected to the rectifier circuit 12 together with a resistor _R3 . Diodes D ₁ and D ₂ are connected in parallel to the thyristor 13 and the resistor R ₃ , the midpoint of which is connected to the gate of the bidirectional thyristor 9 , and a resistor R ₂ is interposed between the thyristor 13 and the anode. ing.

Thus, the AC power source 7 is full-wave rectified by the rectifier circuit 12, and the voltage regulated by the Zener diode ZD charges the capacitor _C2 via the variable resistor _VR1 of the operation switch section 6. Therefore, when the charging voltage of this capacitor C ₂ reaches the voltage value determined by the resistors R ₆ and R ₇ , the PUT 10 is turned on. Therefore, if the variable resistor VR ₁ is variably operated, the charging cycle of the capacitor C ₂ changes according to the change in resistance, and the ON timing of the PUT 10 also changes. In any case, when PUT 10 turns on, the gate of thyristor 13 is triggered and turns on.
As a result, the anode of the thyristor 13 receives not only the rectified output from the rectifier circuit 12, but also the electric blower 8, the gate of the bidirectional thyristor 9, and the diode.
The current continues to flow through D ₁ , resistor R ₃ , thyristor 13 and diode D ₄ . This current continues to flow until the bidirectional thyristor 9 turns on and the voltage across its terminals drops, so even if the load is an inductive load such as the electric blower 8, the bidirectional thyristor 9
will definitely be triggered. Moreover, even after bidirectional thyristor 9 is turned on, thyristor 1
3 is a current that flows through the rectifier circuit 12 and maintains the ON state, so even if the bidirectional thyristor 9 is turned off due to vibration of the main current, it is turned on again. Even when the polarity of the AC power supply 7 is reversed, current similarly flows through the diode D ₃ , the thyristor 13 and the diode D ₂ .
Bidirectional thyristor 9 is turned on reliably.

In this way, the bidirectional thyristor 9 is controlled in accordance with the resistance change caused by the variable operation of the variable resistor VR ₁ , and the input to the electric blower 8 is controlled, and the electric blower 8 is turned off even at a low power factor. Never.

In the conventional system, a high-resistance resistor R ₁₁ is used to stop the electric shock in contrast to the variable resistor VR ₁ of the operation switch section 6.
A resistor R ₁₂ is interposed. For this reason, variable resistance
VR ₁ must also be high resistance (high impedance). The maximum resistance value of this variable resistor VR ₁ regulates the minimum input. In addition, in FIG. 2, SW indicates the OFF position of the variable resistor VR ₁ , and the electric blower 8 is thereby stopped.
However, variable resistors have variations due to mass production, and the deviation is 1 to 15% compared to fixed resistors.
It's about double that. For example, with a fixed resistor, a value of about ±2% can be easily obtained, but with a variable resistor, if the total resistance value exceeds 500KΩ, a deviation of about ±20 to 30% occurs. Therefore, even if the maximum resistance value of the variable resistor is set to 700KΩ for the minimum input setting, it will vary from 490 to 910KΩ due to variations.
If it becomes about 800 to 900KΩ, the electric blower 8 may stop even if it is not in the OFF position, and the minimum input cannot be set.

Therefore, there is a method of selectively using variable resistors to manage the total resistance value, but this method is expensive.

In order to overcome these drawbacks, the applicant has proposed a control circuit as shown in FIG. In this case, the operation switch unit 6 is provided with a variable resistor VR ₁ , a fixed resistor R ₁₃ as a minimum input setting resistance, and a correction fixed resistor R ₁₄ . Here, in area A, the slider 14a is the common conductive pattern PC and the resistance pattern PR of variable resistor VR ₁ .
The resistance pattern PR has a resistance value that increases from the left side to the right side in the figure, and reaches the maximum resistance value at the right end. A conductive pattern PD ₁ for connecting the fixed resistor R ₁₃ is provided on the right side beyond the maximum resistance value of the resistance pattern PR. Therefore, the fixed resistor _R13 is connected in the B region where the slider 14a contacts the common conductive pattern PC and the conductive pattern _PD1 , and the B region corresponds to the lowest input setting position.
In addition, in the C area, the slider 14a is a common conductive pattern.
There is one that only contacts the PC and corresponds to the OFF position. A conductive pattern PD ₂ having a length corresponding to the area A is provided, and is connected to a fixed resistor R ₁₄ . Therefore, the fixed resistor _R14 is connected in parallel with the variable resistor of the variable resistor _VR1 when the slider 14a is in the A region.

In such a configuration, when the electric blower 8 is set to the lowest input, the sliders 14a and 14b are positioned in the B region. As a result, a fixed resistor R ₁₃ is placed in series with the capacitor C ₂ regardless of the variable resistor VR ₁ , and based on the resistance value of this fixed resistor R ₁₃ , the bidirectional thyristor 9 and therefore the electric blower 8 are It will be controlled by the input. In this way, the minimum input setting is made by the fixed resistor _R13 , and the fixed resistor has a variation width of 1/10 or less of the maximum resistance value of the variable resistor, for example ±2 with a carbon film.
%, and the metal film type can easily be mass-produced with a tolerance of about ±0.2%, making it possible to keep the variation in minimum input extremely small and stable.

On the other hand, when the input setting is higher than the minimum input, slider 1
By slidingly displacing 4a and 14b within area A. The resistance of the variable resistor VR ₁ is changed as appropriate, and the input to the electric blower 8 is controlled according to this resistance change. Here, fixed resistor R ₁₄ is variable resistor
A resistor with a resistance lower than the maximum resistance value of VR ₁ and with a small tolerance is used to correct variations in the variable resistor VR ₁ , especially variations in the maximum resistance value. For example, variable resistor VR ₁ is ±30
% tolerance width, and the tolerance width of fixed resistor _R14 is ±2%.
If the resistance value is set to about 1/3 of the maximum resistance value of the variable resistor VR ₁ , the variation can be reduced to around ±10%. More specifically, for example, if the maximum resistance value of variable resistor VR ₁ is 2MΩ, fixed resistor R ₁₄ =
Assuming 700KΩ, the variation in the variable resistor VR ₁ is 1.4 to 2.6MΩ, and the variation in the fixed resistance R ₁₄ is 686 to 714KΩ. As a result, the combined resistance of both has a variation of about 470 to 560KΩ with respect to the ideal value of about 518KΩ, and the variation can be suppressed to ±10% or less. This allows for example fixed resistance
When setting R ₁₃ = 700KΩ, the maximum resistance value will be this value due to the large variation in variable resistor VR ₁ alone.
There are cases where it exceeds 700KΩ, and it may overlap with the lowest input, but the fixed resistor _R14 corrects it to reduce the variation, and it does not overlap with the lowest input.

When the electric blower 8 is to be stopped, the sliders 14a and 14b are positioned in the C area.

Here, when looking at the structure of the variable resistor VR ₁ etc., it is configured as a variable resistor 15 as shown in FIG. That is, a resistance pattern is formed on the surface of the substrate 16.
PR and conductive patterns PD ₁ and PD ₂ are formed (see Fig. 5), and a common conductive pattern PC is formed on the back side (see Fig. 6).
4a is a contact and common conductive pattern that slides on the line between resistance pattern PR and conductive pattern PD ₁
It has contacts that slide on the PC line. In addition, the slider 14b is a contact that slides on the line of conductive pattern PD ₂ and a common conductive pattern PC.
It has a contact point that slides on the line. These contact points are on the same line in the width direction of the substrate 16, and the sliders 14a and 14b are set to operate in conjunction with each other in the sliding direction by the knob 17, and the dimension l is their maximum stroke.

The presence of such a fixed resistor R ₁₃ makes it possible to compensate for the minimum input. However, in our country, there are AC power sources 7 in 50 Hz and 60 Hz regions, and in order to compensate for both regions, it is necessary to use the charging resistor R ₁₃ on the anode side of the PUT 10. In other words, if a fixed resistor is installed in the hose proximal part 5 to compensate for the lowest input, the hose proximal part 5 will generate a 50/60 Hz
frequency switching must be performed.
However, there is little space on the hose proximal part 5 side,
Since shocks are also involved, it is unsuitable to further provide a changeover switch or the like, and reliability deteriorates.

Purpose of the Invention The present invention was made in view of the above points, and an object of the present invention is to obtain an electric blower input control circuit that can be switched for use in a 50Hz region or a 60Hz region while keeping the circuit configuration on the hose proximal side as it is. do.

Summary of the Invention The present invention focuses on a variable characteristic negative resistance element provided on the main body side as a trigger element, and connects a divided resistor that determines its characteristics to a frequency of 50 or 60 Hz via a switch.
By adding a resistor to switch the
The configuration allows for highly reliable 50/60Hz switching without making any changes to the circuit configuration on the hose proximal side.

Embodiment of the Invention A first embodiment of the invention will be described based on FIG. Components that are the same as those shown in FIGS. 1 to 6 are designated by the same reference numerals, and description thereof will be omitted. This embodiment focuses on the point that the ON voltage of the PUT 10 is determined by the dividing resistance ratio of the dividing resistor R ₆ connected between the gate and the power supply and the dividing resistor R ₇ connected between the gate and the _ground . , R ₇ value for 50Hz (or 60
Hz) and connect them in parallel with these resistors R ₆ and R ₇ .
Dividing resistors R ₆ ′ and R ₇ ′ with a voltage dividing ratio set for 60 Hz (or 50 Hz) are provided and can be freely selected by a switch 18 that is switched in conjunction with each other.

According to this configuration, when the minimum input is set by the fixed resistor _R13 , the capacitor _C2 is charged according to this resistor _R13 , and when the charging state is 50Hz,
Although it differs from the case of 60Hz, the dividing resistance for PUT10 changes depending on the frequency difference by changing the switch 18, and the ON voltage changes as R ₆ and R ₇ or R ₆ ' and R ₇ ' differ, so the frequency It is possible to compensate for the minimum input even if the values are different.
In this way, according to this embodiment, the problem is solved by switching the gate side of the PUT 10, so the circuit configuration of the hose proximal portion 5 and the charging circuit on the anode side of the PUT 10 can be left as they are, and variations in the PUT 10 and power supply voltage can be avoided. There is little variation in the circuit stability, and the effect on circuit stability is reduced, making it possible to handle the 50/60Hz region.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is suitable for 50Hz (or 60Hz), for example.
A resistor R _{7 ″ is provided in parallel with the dividing resistor R 7 ,} which is one of the dividing resistors R ₆ and R ₇ set for
It is set for 60Hz (or 50Hz) by R ₇ ''.

This embodiment also provides the same effect as the previous embodiment, but according to this embodiment, the switching portion of the switch 19 is located at one location, making it simpler.

In addition, in place of the resistor R ₇ '', a resistor R _{6 '} ' is provided in parallel with the dividing resistor R ₆ as shown by the broken line in the figure.
It may be set for 60Hz (or 50Hz) by R6 _' ' and resistor _R7 .

Next, a third embodiment of the present invention will be explained with reference to FIG. In this embodiment, for example, for dividing resistor R ₇ which is one of resistors R ₆ and R ₇ set for 50Hz,
_R7 is connected in parallel or floated by the switch 20, and the parallel resistance of resistors _R7 and _R7 and the resistor _R6 are set for 60Hz.

According to this embodiment, the switch 20 operates at any frequency no matter what state it is in.
In practice, it is not necessary to use a normal changeover switch, and it can be achieved by simply shorting or opening a part of the lead wire, making the changeover simple. or,
It has resistances for both 50 and 60Hz regions, so it can be easily switched, and operation tests can be performed with either resistance setting.

Note that instead of the resistor R ₇ , a resistor R ₆ may be provided in parallel with the resistor R ₆ as shown by the broken line in the figure.

Effects of the Invention As described above, the present invention provides a 50/60Hz switching switch and a resistor for the divided resistor that determines the characteristics of the variable characteristic negative resistance element as a trigger element. Switching between 50Hz and 60Hz regions can be performed with high reliability without changing the configuration or the anode side charging circuit of the variable characteristic negative resistance element.

[Brief explanation of drawings]

Fig. 1 is an external perspective view showing a conventional example, Fig. 2 is its circuit diagram, Figs. 3 to 6 show contents of the present applicant's previous proposal, Fig. 3 is a circuit diagram, and Fig. 4 is a circuit diagram. 5 is a plan view, FIG. 6 is a bottom view, FIG. 7 is a circuit diagram showing the first embodiment of the present invention, FIG. 8 is a circuit diagram showing the second embodiment of the present invention, and FIG. FIG. 9 is a circuit diagram showing a third embodiment of the present invention. 4...Hose hand part, 6...Switch operation part,
7...AC power supply, 8...Electric blower, 9...Bidirectional thyristor, 10...PUT (variable characteristic negative resistance element), 18~20...Switch, VR ₁ ...Variable resistance, _R6 ~ R ₇ ……divided resistance, R ₆ ′~R ₆ ……resistance, R ₇ ′~ _{R 7} ……resistance.

Claims (1)

[Claims] 1. An electric blower and a bidirectional thyristor are connected in series to an AC power source, and the charging cycle is adjusted according to a change in resistance caused by the operation of an operation switch including a variable resistor provided at the proximal end of the hose. A variable negative resistor with a characteristic in which a variable capacitor is provided and the ON voltage is determined by the setting of a dividing resistor connected between the gate and the power supply and between the gate and the ground, and the charging voltage of the capacitor is applied to the anode. An electric blower input control circuit characterized in that an element is provided as a trigger element for the bidirectional thyristor, and a switch for 50/60 Hz switching and a resistor for 50/60 Hz switching are provided for the dividing resistor. 2 For the 50 Hz or 60 Hz divided resistor connected between the gate and power supply and between the gate and ground, connect the 60 Hz or 50 Hz divided resistor that can be connected between the gate and power supply and between the gate and ground by switching a switch. The electric blower input control circuit according to claim 1, wherein the electric blower input control circuit is provided as a resistor. 3 For one of the 50Hz or 60Hz divided resistors connected between the gate and power supply and between the gate and ground, select the resistor set for 60Hz or 50Hz with the other divided resistor using a switch. The electric blower input control circuit according to claim 1, wherein the electric blower input control circuit is freely provided. 4 For one of the divided resistors for 50Hz or 60Hz connected between the gate and the power supply and between the gate and ground, connect the divided resistor in parallel with the divided resistor for 60Hz or
An electric blower input control circuit according to claim 1, characterized in that a resistor set for 50Hz is selectably provided by a switch.