JPS60141190A - Input control circuit for motor blower - Google Patents

Abstract

PURPOSE:To set the stable minimum input by providing the minimum input setting resistor separately from a variable resistor and setting the minimum input by the resistor. CONSTITUTION:When a motor blower 8 is set to the minimum input, a slider 14 is disposed in a B region. Thus, a fixed resistor R13 is inserted in series with a capacitor C2 irrespective of a variable resistor VR1, and a bidirectional thyristor 9 and accordingly the blower 8 is controlled to the minimum input on the basis of the resistance value of the resistor R13. On the other hand, the resistance of the resistor VR1 is suitably varied by slidably altering the slider 14 in a region A when the input higher than the minimum input is set, thereby suitably altering the resistance of the resistor VR1, and the input of the blower 8 is controlled in response to the variation in the resistance. When stopping, the slider is disposed in a C region.

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 Fig. 1 shows the external appearance of a conventional vacuum cleaner, in which there is a removable dust collection case 2 at the front of the main body case 1, and a hose insertion port 3 of the dust collection case 2. Hose 4 is inserted. An operation switch section 6 is provided at the hose proximal section 5.

Figure 2 shows the circuit configuration, which basically consists of AC 5
0/60Hz (7)l An electric blower 8 and a bidirectional thyristor 9 are connected in series to an OOV AC power source 7. A protective resistor R1 and a capacitor C1 are connected in parallel to this bidirectional thyristor 9. Furthermore, a characteristic variable negative resistance element PU is provided on the gate side of the bidirectional thyristor 9.
Gate trigger circuit i based on TIO and capacitor C2
ll has been renumbered. This PUTIO is connected to the resistor RT3. It is characterized by R7 and turns ON when a voltage determined by the resistor Re and R7 is applied to the anode side. For this reason, the resistance Re
, R7 are connected to the AC power source 7 by a resistor Rt.

A constant voltage is applied which is full-wave rectified by a rectifier circuit 12 including diodes D3 to D6 and made constant by a Zener diode ZD via a resistor R9. On the other hand, P.U.
A capacitor C2 is connected to the anode of Tlo. Further, the cathode side of PUTl 0 is connected to the gate of the thyristor 13 via resistors R4 and R6. This thyristor 13 is connected to the rectifier circuit 12 together with a resistor R3. A diode D1. is connected in parallel to the thyristor 13 and the resistor R3. D2 is connected, and its midpoint is connected to the gate of the bidirectional thyristor 9, and a resistor R2 is interposed between it and the anode.

Therefore, the AC power supply 7 is full-wave rectified by the rectifier circuit 12,
The voltage regulated by the Zener diode ZD is supplied to the capacitor C via the variable resistor V R1 of the operation switch section 6.
Charge 2. Therefore, when the charging voltage of this capacitor C2 reaches the voltage value determined by resistors R6 and R7, PU':
["IO is turned on. Therefore, the variable resistance V
If R1 is variably operated, the charging cycle of capacitor C2 changes according to the change in resistance, and the ON timing of PtJT LO also changes. In any case PUT 1
When 0 turns on, the gate of the thyristor 13 is 1-triggered and turns on. Due to this, the current continues to flow to the anode of the thyristor 13 not only through the rectified output from the rectifier circuit 12 but also through the electric blower 8, the gate 1 of the bidirectional thyristor 9, the diode D1, the resistor R3, the thyristor 13, and the diode D4. 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 is reliably triggered. It turns out.

Furthermore, even after the bidirectional thyristor 9 is turned on, the thyristor 13 remains in the ON state due to the current flowing through the rectifier circuit 12, so even if the bidirectional thyristor 9 is turned off due to vibration of the main current, this Turn on again. Even when the polarity of the AC power source 7' is reversed, current similarly flows through the diode D3, the thyristor 13, and the diode D2, and the 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 VR1, and the input to the electric blower 8 is controlled, and the electric blower 8 can be turned off even at a low power factor. There isn't.

Problems with the Background Art In the conventional system, the variable resistance V R of the operation switch section 6
1, a high-resistance resistor R11°R1z is interposed to stop the electric shock. Therefore, variable resistor VR1 also has high resistance (
high impedance). The maximum resistance value of this variable resistor VR1 regulates the minimum input. In addition, in Fig. 2, SW indicates variable resistor V.
This indicates the OFF position of R1, whereby the electric blower 8 is stopped. However, variable resistors have variations due to mass production, and the deviation is 1% compared to fixed resistors.
It is about 0 to 15 times higher. 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 500Ω, a deviation of about ±20 to 30% occurs. For this reason, even if the maximum resistance value of the variable resistor is set to 700Ω for the minimum input setting, there will be a range of about 490 to 910Ω due to variation, and if it is about 800 to 900Ω, even if it is not the OFF position. The electric blower 8 may stop, 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.

Purpose of the Invention The present invention has been made in view of the above points, and it is possible to stably and reliably set the minimum input setting while using a variable resistor that causes variations in mass production. The purpose of the present invention is to obtain an electric blower input control circuit that can also alleviate variations in the electric blower.

Summary of the Invention In the present invention, a variable resistor is provided in the operation switch section to enable variable control of the input of the electric blower, and a minimum input setting resistor is further provided separately to set the minimum input. By setting , it is possible to stably set the minimum input without being affected by variations in the resistance value of the variable resistor.In addition, by setting a fixed resistor for correction in parallel with the variable resistor, the value of the variable resistor can be adjusted. It is constructed so that variations can be reduced.

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 and 2 are designated by the same reference numerals, and description thereof will be omitted. In this embodiment, the operation switch unit 6 is provided with a fixed resistor R13 as a minimum input setting resistance together with a variable resistor VRx. Here, the A region is a variable resistance region where the slider 14 is in contact with the common conductive pattern PC and the resistance pattern PR of the variable resistor VR1, and the resistance value of the resistance pattern PR increases from the left side to the right side in the figure. It becomes larger and reaches the maximum resistance value on the right side.

A conductive pattern PD connected to a fixed resistor R13 is provided on the right side exceeding the maximum resistance value of the resistor pattern PR. Therefore, the fixed resistor R13 is in a connected state in the B region where the slider 14 contacts the common conductive pattern PC and the conductive pattern PD, and the B region corresponds to the lowest input setting position.

Further, in region C, the slider 14 contacts only the common conductive pattern PC, and corresponds to the OFF position. In this way, the slider 14 moves by the length of the common conductive pattern PC.

In such a configuration, when the electric blower 8 is set to the lowest input, the slider 14 is positioned in the B area. As a result, the fixed resistor R13 is connected in series with the capacitor c2 regardless of the variable resistor V R1, and this fixed resistor R13 is connected in series with the capacitor c2.
Based on the resistance value of 13, the bidirectional thyristor 9 and therefore the electric blower 8 are controlled to the minimum input. on the other hand,
When the input is set to be higher than the minimum input, the resistance of the variable resistor VRs is appropriately varied by slidingly displacing the slider 14 within the A region, and the input of the electric blower 8 is controlled according to this resistance change. Become. When stopping, the slider is positioned in area C.

Input control is performed in this way, but the minimum input setting is performed by the fixed resistor R13, and the fixed resistor is set to the maximum resistance value variation width of the variable resistor I/]0 or less,
For example, ±2% for carbon film type, ±0.2% for metal film type.
Since a small amount can be easily mass-produced, the variation width of the minimum input can be kept extremely small and stable. Therefore, there is no possibility that the electric blower 8 will stop at the lowest input setting position, and there is no need to select the variable resistor VR1, thereby reducing costs.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the minimum input setting resistance is configured by a fixed resistance R13 and a semi-fixed resistance VR2. According to this embodiment, by varying and fixing the semi-fixed resistor VR2 as necessary, the minimum input can be variably adjusted and the range of use can be expanded. For example, if the cleaning application is limited, the minimum input can be set high (or low). Note that in this embodiment, only the semi-fixed resistor VR2 may be used, but the fixed resistor R13
Due to the presence of the

Next, a third embodiment of the present invention will be explained with reference to FIG. In this embodiment, in addition to the fixed resistor R13, the correction fixed resistor R
This fixed resistor R14 is connected to a conductive pattern PD2 having a length corresponding to the A area. Therefore, the fixed resistor R14 is connected in parallel with the variable resistor of the variable resistor VR1 when the slider 14 is in the A region.

Here, the fixed resistor R14 has a resistance lower than the maximum resistance value of the variable resistor VR't and has a small tolerance, and is used to compensate for variations in the variable resistor VR1, especially variations in the maximum resistance value. For example, variable resistor VR1 has a tolerance range of ±30%, fixed resistor R1
, 4 is set to ±2%, and the resistance value is set to 173rd of the maximum resistance value of the variable resistor VR1, the variation can be reduced to around ±10%. More specifically,
For example, assuming that the maximum resistance value of variable resistor V R1 is 2MΩ and fixed resistor R14 = 700, then variable resistor V R1
The variation is 1.4 to 2.6 MΩ, and the fixed resistance R1
The variation of 4 is 686 to 714 Ω. As a result,
The combined resistance of both is ideal value about 518 and 470 to Ω.
This results in a variation of about 560Ω, which can be suppressed to ±10% or less. As a result, for example, when the fixed resistance R13 is set to 700 Ω, the maximum resistance value may exceed 700 Ω due to large variations in the variable resistor VR1 alone as in the first embodiment. Although it may overlap with the input, according to this embodiment, the variation is corrected to be small by the fixed resistor R14, and the input does not overlap with the lowest input.

Furthermore, a fourth embodiment of the present invention will be explained with reference to FIG.

In this embodiment, the fixed resistor R13 in the third embodiment is
= R14 with Rt4 omitted. Therefore, the fixed resistor R13 is connected to a conductive pattern PD3 having a length spanning the A region and the B region. As a result, if the slider 14 is in the C region, it is OFF, but if it is in the B region, only the fixed resistor R13 is present, and the minimum input setting is made by this fixed resistor R13. Moreover, when the slider 14 is placed in the A region, the variable resistance value of the variable resistor V R1 and the fixed resistor Rt3
are connected in parallel, and input control of the electric blower 8 is performed by the combined resistance of both. Specifically, the maximum resistance value of variable resistor VR1 is 2MΩ, fixed resistor R13 (= R14) = 70
It is set like Ω to 0.

Effects of the Invention As described above, the present invention provides a variable resistor in the operation switch section to enable variable control of the input of the electric blower. By setting the input using this resistor,
The variation in resistance value is extremely small compared to that of a variable resistor, allowing stable minimum input settings.
By including a semi-fixed resistor, the minimum input can be variably adjusted to expand the range of use.Also, when the resistance of the variable resistor is varied, a correction fixed resistor is connected in parallel, so it can be adjusted according to the minimum input. Resistance variations during variable resistor operation can also be suppressed to a minimum, and this can be further simplified by unifying the minimum input setting resistor and the correcting fixed resistor.

[Brief explanation of drawings]

Fig. 1 is an external perspective view showing a conventional example, Fig. 2 is a circuit diagram thereof, Fig. 3 is a circuit diagram showing a first embodiment of the present invention, and Fig. 4 is a diagram showing a second embodiment of the present invention. FIG. 5 is a circuit diagram showing a third embodiment of the present invention, and FIG. 6 is a circuit diagram showing a fourth embodiment of the present invention. 5... Hose proximal part, 6... Switch operation part, 7...
... AC power supply, 8... Electric blower, 9... Bidirectional thyristor, 11... Gate trigger circuit, V R1.
...Variable resistance, Ru...Minimum input setting resistance, V R2
...Semi-fixed resistor, R14...Fixed resistor for correction Applicant: Tokyo Electric Co., Ltd.

Claims (1)

[Scope of Claims] 1. An electric blower and a bidirectional thyristor are connected in series to an AC power source, and both of the above are controlled in response to a change in resistance caused by the operation of an operation switch section including a variable resistor provided at the hose proximal section. In the electric blower input control circuit, which is provided with a gate trigger circuit that controls a tropic thyristor and controls the input of the electric blower by controlling the bidirectional thyristor, the operation switch section is configured to set a minimum input setting resistance to the variable resistor. When the minimum input setting is set, the input of the electric blower is controlled by this minimum input setting resistance, and when the input is set above the minimum input, the input of the electric blower is controlled by changing the resistance of the variable resistor. An electric blower input control circuit characterized by: 2. The electric blower input control circuit according to claim 1, wherein the minimum input setting resistance includes at least a semi-fixed resistance. 3. An electric blower and a bidirectional thyristor are connected in series to an AC power source, and the bidirectional thyristor is controlled according to resistance changes caused by operation of an operation switch section including a variable resistor provided at the hose end. Goo 1-1 - In an electric blower input control circuit which is provided with a trigger circuit and controls the input of an electric blower through bidirectional thyristor control, the operation switch section selects a minimum input setting resistance with respect to the variable resistor. A correction fixed resistor with a resistance lower than the maximum resistance value of the variable resistor is provided in parallel with this variable resistor when the variable resistor is operated, and when the lowest input setting is made, the lowest input setting position is set. An electric blower input control circuit characterized in that the input to the electric blower is controlled by a resistor, and when the input is set to a minimum input or higher, the input to the electric blower is controlled by a combined resistance of a resistance change of a variable resistor and a fixed resistance for correction. 4. The minimum input setting resistance and the correction fixed resistance are set in common, and when the minimum input setting is set, the input of the electric blower is controlled by this minimum input setting resistance, and when the input setting is higher than the minimum input, the variable resistor is used. 4. The electric blower input control circuit according to claim 3, wherein the electric blower input control circuit controls the human power of the electric blower by the combined resistance of the change and the minimum input setting resistance.