JPS6149687A - Control circuit of fan - Google Patents

Abstract

PURPOSE:To obtain a control circuit which can be utilized for a fan by an inexpensive small terminal number type microcomputer by outputting the firing of a light emitting element and inputting a signal of an operation switch by one input/output terminal of the microcomputer. CONSTITUTION:A microcomputer 43 has input/output terminals 6-11T for receiving signal inputs of operation switches 35-40 for selecting the operation of a fan in one half wave range of an AC power source by the input/output terminals, and produces an output for firing light emitting elements 28-33 for indicating the operating states of another one half wave range. Thus, the number of the terminals of the microcomputer can be reduced to be utilized for the fan.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a microcomputer-controlled electric fan control circuit having a microcomputer for controlling a fan motor.

Conventional configurations and their problems Recently, microcomputers have been introduced in the field of electric fans, and new electric fans that have never existed before are being manufactured. However, electric fans are low-priced products among home appliances, and because they have a long history, people tend to have a fixed image of the product. It is a troublesome product. In other words, since it has a single function, it is a product with a strong focus on price. By the way, it goes without saying that installing a microcomputer in such an electric fan would be extremely expensive. Furthermore, since the control of the electric fan is mainly based on timer control, an extremely large number of light emitting diodes are required to display the time, which is one of the factors that increases the difficulty in terms of price. Although the need for a large number of light emitting diodes is one of the reasons for the low cost, the more important issue is the number of terminals on the microcomputer used to light up the light emitting diodes. In particular, the number of terminals on LSIs such as microcomputers is 16°18, 22,
28, and the higher end models with more terminals are generally more expensive. In this sense, it is an essential condition for electric fans to use a microcomputer with as few terminals as possible. However, as mentioned above, the timer, which is the main control element of the electric fan, requires many light emitting diodes to display the remaining time.
Microcomputers always have 4 to 5 fixed terminals (for example, 6J terminals, etc.) that users cannot use freely.
Considering the number of pins required, it is extremely difficult to use a microcomputer with a low number of terminals such as 16 pins or 18 pins to control an electric fan, and generally higher-end devices with a higher number of terminals are sacrificed for price. Currently, microcomputers with a small number of terminals are used, such as by using different types of microcomputers or displaying multiple states by blinking a single light emitting diode.0 Purpose of the Invention Book The present invention is intended to eliminate these conventional problems, and uses one input/output terminal of a microcomputer to provide an output that lights up a light emitting element that displays the operating state of the fan, and an operation switch that sets the operating state of the fan. The purpose of the present invention is to provide a control circuit that allows a low-cost, low-terminal-number type microcomputer to be used for an electric fan by inputting signals such as the following.

Structure of the Invention In order to achieve this object, the electric fan control circuit of the present invention includes a fan motor and a microcomputer that controls the fan motor. The dual-purpose terminal accepts the signal input of the operation switch to select the operation of the fan during one half-wave period of the AC power supply, and the output lights up a light emitting element to display the operating status during the other half-wave period. The number of terminals on the microcomputer can be reduced because the cycle of the AC power supply can be utilized to serve as the signal input terminal for the operation switch, etc., and the output terminal for the operation status indicator light from the operation switch, etc. This has the effect that the switching timing setting circuit is extremely simple.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and is a control circuit for an electric fan, which is based on a microcomputer with a 16-pin terminal, six operation switches, and nine light emitting diodes.

1 is an AC power source 2 is a fuse, 3 is a diode, 4 is a resistor, 6 is a PNP) transistor, 6 is a resistor, 7 is an electrolytic capacitor, and 8 is a constant voltage diode. Low-voltage DC power supplies used in computers, etc. are made. 10 is resistance, 11
is a diode, 12 is an NPN) transistor, 13.1
4 is a resistor, and 15 is a PNP transistor. 16.
17 is a resistor, 18 is an NPN) transistor, 19 is a resistor,
2o is a capacitor, 21 is a resistor, 22 to 27 are resistors, 2
8 to 33 are light emitting diodes, 34 to 40 are operation switches, 41 is a capacitor, and 42 is a resistor. 43 is a microcomputer, 44 and 46 are resistors, 46 is a buzzer,
47-52 are resistors, 63-55 are light emitting diodes, 56
68 is a thyristor, and 59 is a fan motor. The operation will be briefly explained below. resistance 1
0, diode 11, and NPN transistor 2 are circuits that generate a rectangular wave that determines the timing of the operation that is the center of the present invention, and input it to the microcomputer. When point a is higher than the fuse 2 side, the current passes through the resistor 10 and the emitter of the NPN transistor 12, and from the emitter of the PNP transistor 5 to the paste voltage regulator diode 8. Reach the street Hughes 2 side. Therefore, the NPN transistor 12 is turned on, and the collector points 5 drop to the L level. When the voltage of the AC power source 1 of the correspondence is higher on the fuse 2 side, the current becomes a circuit current of the microcomputer 43, etc., and passes from the emitter side of the NPN transistor 12 through the diode 11 and the resistor 10 and reaches point a. Therefore, the NPN transistor 12 is turned off in this section. Figures a and b of the waveform time chart in Figure 2 show this situation, where a is the AC power supply 1.
Figure b is a time chart of the voltage waveform of the AC power source 1, which is a rectangular wave that is at the level during the positive half-wave of the AC power source 1 and becomes H level during the negative half-wave. It has become. Since the point changes like this, resistance 1
3, 14, and a PNP transistor 15, the transistor 15 is in an off state and the collector potential at point C is in a floating state (floating). Next time the light reaches L level, PNP
Conversely, the transistor 15 is turned on and the point C becomes H level. On the other hand, resistor 16°17, NPN transistor 1
In the circuit composed of transistors 8 and 8, the transistor 18 (NPN) is turned on and the collector potential is low when it is at H level.
level. Similarly, when the potential of the switch is at L level, it is NP.
The N transistor 18 is turned off and its collector potential becomes a floating state. A time constant circuit composed of a resistor 19 and a capacitor 2Q is a reset circuit for accurately starting the program of the microcomputer 43.

By the way, a resistor 21 and light emitting diodes 28 to 33 are connected to the collector (point C) of the PNP transistor 16 described earlier, and each of the light emitting diodes 28 to 33 serves as an input/output terminal 11T of the microcomputer 43.

It is connected to 10T, 9T, BT, 7T, and 6T, and these input/output terminals are further connected to pull-up resistors 22 to 27.
are connected. Also, these input/output terminals 6T~1
Operation switches 34 to 4Q are connected to 1T, and the other terminals of these operation switches 34 to 4Q are combined into one and connected to the collector of the NPN transistor 18 mentioned earlier. Time charts illustrating these operations are shown in c, d, and e of FIG. 2, where C is a time chart of the collector potential of the PNP transistor 15, and F indicates a floating state section. d is a time chart showing the operating state of the point d, that is, the input/output terminal 11T, and since the operation of this terminal is exactly the same for the other input/output terminals 10T to 6T, the operation of each input/output terminal is Explanation will be omitted. By the way, in the section ``d'' in Figure d, there is a light emitting diode 28 that displays the operating status of the fan.
Light-emitting diode 2
When turning on 8, use the input/output terminal 11 within this section.
By setting T to output mode and setting it to L level, point C becomes H.
Since the voltage is at the same level, the light emitting diode 28 is turned on through the resistor 21. If it is not necessary to light the light emitting diode 28 in this section, the input/output terminal 11T may be set to H level. Next, section B is a section where the signal state of the operation switch 34 is input, and naturally the input/output terminal A1a 11T is in the input mode. B section is PNP) The transistor 15 is in the off state g N P N The transistor 18 is in the on state, and if the operation switch 34 is not pressed at this time, the signal state of the input/output terminal 11T is due to the pull-up resistor 22. It is at H level.

However, if the operation switch 34 is pressed, the NPN transistor 18 is turned on, so the input/output terminal 1
1T changes to L level. This situation is shown in the time chart at e in Figure 2, which shows the time t in the middle of the section.
An example in which the operation switch 34 is pressed at 0 is shown. The operation switch 34 is kept pressed for T time from time t0 to time t5. During this time, t0 → 11, 12 → in the interval to
t3. During the period from t4 to t5, the signal state of the input/output terminal 11T becomes L level, and the microcontroller can be confirmed by this input signal. This operation also applies to other operation switches.
Since the operation switch 34 of the computer 43 is pressed in the same way in Sochi 35 to 40, the explanation will be omitted as in the case of the light emitting diode. By the way, regarding the lighting of the light emitting diode 28 in the section B, strictly speaking, the light is off in the B section because the input/output terminal 11T is in the input mode, so if you look at it as a whole, it can be said that it is lit. It is blinking instead. However, to the human eye, blinking more than 4 times per second appears to be continuous due to an afterimage phenomenon, and even in the 5011z area where the number of blinks is small, 1
It blinks 950 times per second, which appears to be continuous lighting, and there is no problem with the front thread. From this point of view, it is very effective to use the cycle of the AC power supply 1 as the mode switching timing of the microcomputer. A time constant circuit composed of a capacitor 41 and a resistor 42 is for an oscillation circuit that determines the basic operating frequency (clock frequency) of a microcomputer 43, and 43 is a 16-pin microcomputer, and 1T to 16T are its terminals. 1T to 3T are output terminals for operating triacs 56 to 58 for switching the rotational speed of the fan motor 590, and 4T is an output terminal for sounding the buzzer 46. Since these terminals are not directly related to the operation of the present invention, a detailed explanation of their operation will be omitted. Note that the potential of the terminal is inputted to the microcomputer 43 through the terminal 12T.

Effects of the Invention - As described above, according to the present invention, one input terminal of a low-terminal type microconbeater, which is generally said to be low in price, is a light emitting diode that displays the operating status of an electric fan using the cycle of the AC power supply. Since it can be used both as an output terminal for lighting up light-emitting elements such as and as an input terminal for inputting signals from operating switches, etc., the number of terminals on the microcomputer can be reduced, while the circuit for setting the switching timing is extremely simple. Furthermore, the flickering of the light-emitting element when it is lit is completely invisible to the eye. Furthermore, since the time interval of the switching timing is completely synchronized with the AC power supply, it has great effects such as being able to be used as a reference time for a fan delay timer or as a power supply voltage zero-cross signal when starting a fan motor.

FIG. 1 is a circuit 1 of an embodiment of the electric fan control circuit of the present invention, and FIG. 2 is a time chart of waveforms at each reference point in FIG. 1.

1... AC power supply, 28... Light emitting diode (light emitting element), 34... Operation switch, 43
・・・・・・Microcomputer, 69・・・・・・
fan motor.

Name of agent: Patent attorney Toshio Nakao and 1 other person
2 Figure

Claims (1)

[Claims] It is equipped with a fan motor and a microcomputer that controls the fan motor, and this microcomputer has an input/output terminal, and the input/output terminal selects the operation of the fan during one half-wave period of the AC power supply. A control circuit for a fan that receives a signal input from an operation switch for the operation of the AC power source and outputs an output that lights up a light emitting element to display the operating status of the fan on the other section of the AC power supply.