JPS59139889A - Input control circuit for motor-driven blower - Google Patents

Abstract

PURPOSE:To commonly use the GND lines of an AC circuit and a DC circuit by providing a zero cross detector for operating a timer circuit. CONSTITUTION:A condenser C8 is discharged when an AC crosses zero voltage, a timer circuit 10 does not operated, a transistor Tr2 or Tr3 is turned ON by the operation voltage after crossing the zro voltage, a transistor Tr5 is turned OFF, thereby starting the operation of the timer circuit 10, i.e., the charging of the capacitor C8. When the voltage at the point A becomes the prescribed value, a bidirectional thyristor 9 is turned ON. In this manner, the GND lines of an AC circuit and a DC circuit can be used commonly.

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 its problems Figure 1 shows a conventional electric blower input control circuit, in which an electric blower (2) and a bidirectional thyristor (3) are connected in series to an AC power source (1). A combination circuit of an integrating circuit (4) of a capacitor C1 and a resistor R8 and a diac (5) is used for the gate input of the bidirectional thyristor (3). In this case, since the input from sensors such as wind sensors is treated as DC, a rectifier circuit (6) etc. is used as an interface between them, and the ground GND line between the AC circuit and DC circuit is not common, and the circuit is complicated. Furthermore, although Fig. 2 is a simplified version of Fig. 1, since AClooV of the AC power supply (1) is reduced in pressure by resistor R1, this resistor R1, that is, the leader resistor, generates a large amount of heat. .

Purpose of the Invention The present invention was made in view of the above points, and it is possible to make the GND line of the AC circuit and the DC circuit common,
Another object of the present invention is to obtain an electric blower input control circuit that can reduce heat generation of a bleeder resistor.

Summary of the Invention The present invention provides a zero-cross detection circuit that detects the operating voltage after the zero potential cross of the AC power supply and operates the timer circuit, thereby making it possible to share the GND line between the AC circuit and the DC circuit. Therefore, the configuration is such that circuit control can be simplified.

Embodiment of the Invention A first embodiment of the invention will be described based on FIG. First of all, basically an AC 50/6011z 100V AC power supply (power) is connected in series with a 11f Ih blower (8) and a bidirectional thyristor (9). A timer circuit 00) is connected to the gate of 9). This timer circuit (10
) mainly consists of a resistor 7°R58, an integrating circuit with a capacitor C8, a comparator 01), and a bidirectional thyristor (12).
,,,FL,, ,R,,,R2O,R,,.

It is configured to include R2□VR. Here, the input from the sensor is given to diode D3. Such a timer circuit (10) is supplied with a DC' power supply, and therefore, the AC power supply (7) is supplied with a remote control circuit (
13) is connected. That is, the 15V line is secured by the Zener diode ZD, and the 7.5V line is secured by the Zener diode ZD2.
Transistor Trl, unidirectional thyrisk+l1l),
It is composed of a hand switch (5). R2 is a current limiting resistor, R31R4 is an electric shock prevention resistor, R2 is a current limiting resistor, R is a gate protection resistor, "?
+"8 r- is the leader resistance.

Therefore, the zero cross detection circuit (lυ) is connected to the timer circuit (10). Zero cross detection circuit 0
6) is mainly composed of transistors Tr2 to Tr5,
It includes resistors R, , R1, , R,6, etc. Here, the transistor Tr5 is connected in parallel to the capacitor C8.

Furthermore, the voltage dividing resistors R1□ and R13 are connected in parallel to the AC power source (7).

In such a configuration, a signal from the sensor is input to the diode D, and the potential at point A of the capacitor C8 gradually increases due to the action of the integrating circuit.

At this time, the comparator 0υ is resistor R, , VR, R,
A reference voltage is set by o, and when the potential at point C1A becomes higher than this reference voltage, the output of the comparator (11) becomes H level. As a result, a current flows to the gate of the bidirectional thyristor (12) at the previous stage, turning on the bidirectional thyristor (12), which triggers the gate of the bidirectional thyristor (9) and turning it on. here,
The setting value (reference voltage) of one terminal of the comparator (11) determines the minimum input of the electric blower (8). By increasing the input value, the slope of the integrating circuit is changed, and the bidirectional thyristor (9) Control all inputs by changing the conduction time.

The operation of the zero-cross detection circuit (16) for such a timer circuit (10) will be explained. Now, in the positive direction of AC, the transistor Tr2 is turned on and the transistor Tr3 is turned off. Therefore, transistor Tr4.

Tr6 is 01"F'. Then, at the moment when the alternating current turns from the positive direction to the negative direction and crosses the zero' spiral level, the transistor T
r2 is turned off and transistor Tr5 is turned on. Therefore, the charge stored in the capacitor C8 is discharged by this transistor Tr11, and the potential at point A drops to OV. Then, after the zero potential crosses, when the operating voltage is reached in the negative direction, the transistor TrB.

Tr4 is turned ON and transistor Tr6 is turned OFF'. As a result, the timer circuit (10) starts operating and starts charging the capacitor C8. Then, when the potential at point A reaches a predetermined voltage, the bidirectional thyristor (9) is turned on by the action of the comparator (tL bidirectional thyristor (12)) as described above.Then, the alternating current changes from the negative direction to the positive direction. At the moment when the opposite zero potential is crossed, the transistor Trl and 'Pr4 are OF'P L, and the transistor TrIl is turned on, the charge of the capacitor C8 is discharged, and the potential at point A becomes OV.Then, after the zero potential crosses, When the operating voltage is in the positive direction, the transistor Tr2 becomes O.
N and the transistor Tr6 becomes 01i'F. Therefore, similar operations are repeated.

In other words, when the AC zero potential crosses, the capacitor is discharged and the timer circuit (10) does not operate, and the operating voltage after the zero potential cross causes the transistor Tr2 or Tr
3 is ONI, and the transistor Tr6 turns OFF, thereby starting the operation of the timer circuit (10), that is, charging the capacitor C8, and when the potential at the point A reaches a predetermined value, the bidirectional SIRISK (9) turns ON. It is a matter of fact.

Therefore, according to this embodiment, the zero cross detection circuit (
16), the comparator (11) of the timer circuit (H)) creates the input for the gate trigger of the bidirectional thyristor (9), and as shown in the figure, the GND line of the AC circuit and the DC circuit are shared. The circuit can be controlled based on this GND line, which simplifies the circuit configuration.

Next, a second embodiment of the present invention will be explained with reference to FIG. In this embodiment, the input side of the zero-cross detection circuit (16), that is, one end of the resistor RI2, is connected between the electric blower (8) and the anode of the bidirectional thyristor (9).

Bidirectional thyristor (9) turns ON when gate triggered
Therefore, when connected as shown in Fig. 4, if the potential at point A becomes even slightly higher than the reference voltage of one terminal, the bidirectional thyristor (121) turns on, causing the bidirectional thyristor (
9) turns on. Thus bidirectional thyristor (9)
When turned on, the anode terminal of the bidirectional thyristor (9) falls to the GND line, and the transistor Tr! ~Tr4
is OFF L, and the transistor Try is ON,
The charge on capacitor C8 is discharged. Therefore, the output of the comparator αυ becomes L level, and no current flows through the bidirectional thyristor (1). In other words, the timer circuit (1)
0) operates only from the time when the operating voltage is detected in the zero-cross detection circuit Q to the time when the bidirectional thyristor (9) is turned on, and has a lower power consumption than the first embodiment. , the heat generation at the puller resistance horse ~R is also reduced.

Effects of the Invention Since the present invention is configured as described above, the GND line can be shared between the AC circuit and the DC circuit, and the circuit can therefore be simplified.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams showing a conventional example, FIG. 3 is a circuit diagram showing a first embodiment of the present invention, and FIG. 4 is a circuit diagram showing a second embodiment of the present invention. . 7. AC power supply, 8. Electric blower, 9. Bidirectional thyristor, 10. Timer circuit, 16. Zero cross detection circuit. Applicant: Tokyo Electric Corporation

Claims (1)

[Claims] 1. An electric blower and a bidirectional thyristor are connected in series to an AC power source, and a timer circuit to which DC power is supplied is connected to the gate of the bidirectional thyristor.
In what controls the trigger, what about the AC power supply? An electric blower input control circuit comprising a zero-cross detection circuit that detects an operating voltage after a potential cross and operates the timer circuit. 2. The dynamic air blowing input control circuit according to claim 1, wherein the input side of the zero cross detection circuit is connected between an electric blower and an anode of a bidirectional cyrisk.