JPH0283486A - Hand dryer control apparatus - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation of a hand dryer due to the noise of a power supply at a time when a hand is not detected by an ultrasonic sensor by providing a noise signal absorbing means for absorbing instantaneously generated high voltage noise. CONSTITUTION:A small capacity condenser 29 as a noise ON-signal absorbing means is connected to the rear stage of the comparator 28 constituting the judge circuit 22 in a hand dryer control apparatus. By this method, the high voltage noise generated in the same AC power supply line invades a control circuit 11 through a triac 13 and a transistor 32 and, even when the ON-signal is generated from the judge circuit 22 based on said high voltage noise, the ON-signal based on the high voltage noise can be absorbed by the condenser 29 and the erroneous operation of a timer circuit 23 is prevented to prevent the erroneous operation of both of a motor 4 and a heater 7.

Description

[Detailed description of the invention]

[Industrial Application Field] This invention relates to a hand dryer that is installed in washrooms, toilets, etc. and that dries wet hands with hot air. The present invention relates to a hand dryer control device for operating the hand dryer. [Prior Art] As a conventional hand dryer and its control device, there is one shown in FIG. That is, the hand dryer 40 is composed of a heater 41 that heats air, a motor 42 that rotates a blower fan (path shown) that blows air to the heater 41, a triac 43 that performs a switch operation, and the like. or,
The hand dryer 400 control device 44 includes an ultrasonic sensor 45 that detects a hand placed on the hot air blowing side, an amplification circuit 46 that converts the detected current from the ultrasonic sensor 45 into voltage and amplifies it, and an amplification circuit 46 . A determination circuit 47 that compares the amplified voltage with a reference voltage and outputs an on signal when the amplified voltage of the amplification circuit 46 is large, and a timer circuit 48 that turns on the transistor 49 for a predetermined period of time based on the on signal from the determination circuit 47. It is composed of etc. This transistor 49 is connected to the triac 43.
When the transistor 490 turns on based on the on signal from the determination circuit 47, the triac 43 performs a switching operation, which causes the AC power supply (AC100
bolts) are supplied to the heater 41 and motor 42 to drive them. In the control device 44 using the ultrasonic sensor 45, when high voltage noise generated when turning on and off other devices connected to the same outlet enters through the trier, the transistor 43, and the transistor 49, the determination circuit 47 has a problem in that it outputs an on signal based on the high voltage noise even though no hand is detected, turning on the transistor 49 and causing the hand dryer 40 to malfunction. For this reason, conventionally, in order to prevent malfunction of the control device 44 due to high voltage noise, a large capacity capacitor 50 is provided at the front stage of the amplifier circuit 46 to absorb the high voltage. [Problems to be Solved by the Invention] However, by providing the capacitor 50 with a large capacity as described above, malfunction of the control device 44 due to high voltage noise can be prevented, but the normal detection signal of the ultrasonic sensor 45 is also absorbed, so this capacitor 5
There is a problem in that the determination circuit 47 does not output an ON signal until the battery is charged to 0, which deteriorates the operating characteristics of the hand dryer 40. This invention was made to solve the above problems, and its purpose is to prevent malfunctions of the hand dryer due to noise in the AC power line, and to improve the operating characteristics of the hand dryer. An object of the present invention is to provide a hand dryer control device.

[Means to solve the problem]

In order to achieve the above object, a first invention provides a heater that is driven by an AC power source and heats air; A hand dryer equipped with a blower fan that blows out air and a switch means that turns on AC power to the heater and the blower fan, an ultrasonic sensor that detects a hand placed on the warm air outlet side of the hot air outlet; , a drive control means for comparing a detection signal of the ultrasonic sensor with a reference voltage and outputting an on signal for causing the switch means to perform an AC power-on operation when the detection signal is large; The gist of the hand dryer control device is to provide a hand dryer control device comprising noise-on signal absorbing means, which is interposed between the drive control means and the drive control means, and absorbs the on-signal based on the noise intruding from the AC power supply, among the on-signals of the drive control means. do. Further, a second invention includes a heater that is driven by an AC power source and heats air, and an air blower that is also driven by an AC in and blows air to the heater and blows out warm air from a hot air outlet. In a hand dryer comprising a fan and a switch means for supplying AC power to the heater and the blower fan, an ultrasonic sensor detects a hand placed on the hot air outlet side of the hot air outlet, and the ultrasonic sensor drive control means for comparing a detection signal from a reference voltage with a reference voltage and outputting an on signal when the detection signal is large; and a drive control means for electrically separating the drive control means and the switch means. The gist thereof is a hand dryer control device comprising: and a relay means for causing the switch means to perform an alternating current power-on operation based on an on signal from the drive control means. [Operation] According to the first invention, the ultrasonic sensor detects a hand placed on the hot air blowing side and outputs a detection signal. The drive control means compares the detection signal of the ultrasonic sensor with a reference voltage, and when the detection signal is large, outputs an on signal for causing the switch means to perform an AC power-on operation. Based on this ON signal, the switch means performs an operation of turning on the AC power, and the heater and motor are driven. Furthermore, when the ultrasonic sensor does not detect a hand, even if the drive control means outputs an on signal based on noise that has entered from the AC power supply through the switch means, the on signal is absorbed by the noise on signal absorption means. Therefore, the switch means does not perform a switch operation, and malfunction of the hand dryer is prevented. Further, according to the second invention, when the ultrasonic sensor detects the hand and outputs the detection signal, the drive control means compares the detection signal of the ultrasonic sensor with the reference voltage, and when the detection signal is large, the drive control means compares the detection signal of the ultrasonic sensor with the reference voltage. Outputs on signal. The relay means causes the switch means to perform an AC power-on operation based on this ON signal,
This drives the heater and motor. Further, when the ultrasonic sensor does not detect a hand, the drive control means and the switch means are electrically separated by the relay, so that noise from the AC power source does not enter. Therefore, since the drive control means does not output an ON signal, the relay means does not cause the switch means to perform an AC power-on operation, and malfunction of the hand dryer is prevented. [First Embodiment] A first embodiment embodying the first invention will be described below with reference to FIG. 1.2. FIG. 2 shows a hand dryer 1, in which a duct 3 is attached to a mounting plate 2 arranged and fixed inside a case (path shown).
A fan/motor section 6 consisting of a motor 4 and a blower fan 5 driven by the motor 4 is provided at the upper part of the duct 3. Also, the upper duct 3a at the bottom of the duct 3
and the lower duct 3b equipped with the hot air outlet 3C,
A heater 7 having PTC (positive temperature coefficient) characteristics and a heater section 9 consisting of radiation fins 8 and the like are provided. When the motor 4 drives the blower fan 5 and the heater 7, the heat radiation fins 8
The air is heated when passing through, and hot air is blown out from the hot air outlet 3c. A pair of ultrasonic sensors 10 serving as both transmitting and receiving sensors are attached to the left and right side walls of the lower duct 3b, and each ultrasonic sensor 10 uses reflected waves to activate the hot air outlet 3.
It is designed to detect objects (hands) placed in the sensing range below C. On the other hand, a control circuit 11 is provided on the mounting plate 2 as a drive control means for controlling the drive of the fan motor section 6 and the heater section 9 based on detection signals from both the ultrasonic sensors 10.
A control panel C is installed. Also, the mounting plate 2 has a transformer 12. Triac 13 as a switch means
．． A switch 14, a heater 15, etc. are attached. Next, the electrical configuration of the hand dryer control device is
This will be explained based on the diagram. As shown in FIG.
The motor 4 and the heater 7 are connected in parallel through the TRIAC 13, and the motor 4 and the heater 7 are supplied with power and driven by the operation of turning on the AC power of the triac 13. Further, a step-down circuit 17 is connected to the AC power source through a terminal terminal 16 for supplying a driving source 2 to the control circuit 11. The step-down circuit 17 is composed of a full-wave rectifier 18, capacitors 01 to C3, and a voltage divider 19.
DC drive power supply V2 which is a step-down and rectified source of 00 port t-
(12 volts in this example). The control circuit 11 generally includes an oscillation circuit 20 and an amplifier circuit 2.
1, a determination circuit 22, and a timer circuit 23, and the ultrasonic sensor 10 is connected to an oscillation circuit 20 and an amplification circuit 21. The oscillation circuit 20 consists of an oscillation IC 24, resistors R1 and R2, a variable resistor R3, capacitors C4 and C5, and a diode D1, and has a predetermined frequency (40.5kHz in this embodiment).
The signal is output to the ultrasonic sensor IO. The amplifier circuit 21 includes amplifiers 25 to 27 and capacitors C6 to C.
8, resistors R4 to R8 and a Zener diode D2; an amplifier 25 converts a current signal corresponding to the reflected wave received by the ultrasonic sensor 10 into a voltage signal; ), and the amplifier 27 further amplifies the output signal of the amplifier 26 and outputs it to the determination circuit 22. This is because the waves reflected from a fixed object do not change in intensity, but the ultrasound reflected from a person's hand is distorted and changes in intensity depending on the movement of the hand, so only this distorted part is amplified. This allows it to sense your hand. The judgment circuit 22 includes a comparator 28, a resistor R9゜RIO,
R12, variable resistor R1,1, resistor R9 and resistor R
The reference voltage determined by the IO and the variable resistor RLI is compared with the amplified signal from the amplifier circuit 21, and when the amplified signal is larger than the reference voltage, an on signal is output. A capacitor 29 serving as noise-on signal absorbing means is connected to the comparator 28 via a resistor R13. As this capacitor 29, a capacitor with a small capacity is used, and it is designed to be charged instantaneously when an ON signal is output from the determination circuit 22. The timer circuit 23 includes counters 30, 31 and resistors R14 to R.
19, capacitors 09 to C12, a diode D3, and a transistor 32. The collector terminal of the transistor 32 is connected to the gate terminal of the trybook 13. This timer circuit 23 is connected to the determination circuit 22.
The transistor 32 is turned on based on the on signal from the triac 13, and the motor 4 and heater 7 are driven. Next, the operation of the hand dryer control device configured as described above will be explained. When the switch 14 is turned on to turn on the power, the oscillation circuit 20 sends a 40.5 kHz signal to both ultrasonic sensors 10, and both ultrasonic sensors 10 send out ultrasonic waves. When there is an object within the sensing range of both ultrasonic sensors 10, the ultrasonic waves are reflected, and the returned reflected waves are received by both ultrasonic sensors 10 and converted into current signals. This current signal is converted into a voltage signal by the amplifier 25 of the amplifier circuit 21,
The next stage amplifier 26 generates a low frequency signal (2~
20 Hz) portion is amplified. The output signal from the amplifier 26 is amplified by the amplifier 27 and sent to the determination circuit 22.
is output to. Then, the amplified signal from the amplifier 27 is compared with a reference voltage in the determination circuit 22, and if the amplified signal is larger than the reference voltage, the determination circuit 22 outputs an on signal. When the capacitor 29 is instantaneously charged by this ON signal, the ON signal is input to the timer circuit 23, and the timer circuit 23 activates the transistor 32 for a predetermined period of time (1 to 3 in this embodiment).
(about seconds). Based on the drive of the transistor 32, the triac 13 is turned on, the motor 4 and the heater 7 are energized by the AC 100 volt power source, and hot air is blown toward the hand from the hot air outlet 3c. Now, when the ultrasonic sensor 10 is not detecting a hand, the high voltage noise that occurs momentarily when other devices connected to the same power source such as the same outlet are turned on and off is generated at the gate terminal of the triac 13 and the transistor 32. When entering the control circuit 11 through the collector terminal, the amplifier circuit 21
is a 0 judgment circuit 2 which amplifies it and outputs it to a judgment circuit 22.
2 is an on signal based on this high voltage noise (referred to as a noise on signal) because the high voltage noise is larger than the reference voltage.
Output. However, since this noise-on signal is instantaneous, it is absorbed by the capacitor 29, so that the noise-on signal is not input to the timer circuit 23. Therefore, since the transistor 32 of the timer circuit 23 does not operate, the trier 7 is not turned on, and the motor 4 and heater 7 are not driven. As described above, in the hand dryer control device of this embodiment, a small capacitor 29 as a noise-on signal absorbing means is installed after the comparator 28 constituting the determination circuit 22.
Since the high voltage noise generated on the same AC ttA line enters the control circuit 11 via the triac 13 and the transistor 32, and the ON signal is output from the determination circuit 22 based on this high voltage noise, The ON signal based on this high voltage noise can be absorbed by the capacitor 29, thereby preventing the timer circuit 23 from malfunctioning, thereby preventing the motor 4 and the heater 7 from malfunctioning. In addition, in the hand dryer control device of this embodiment, since the capacitor 29 has a small capacity, the ultrasonic sensor 1
Based on the normal detection signal that 0 has detected the hand, the judgment circuit 22
The on signal output from the ultrasonic sensor 10 becomes a continuous long signal, and the capacitor 29 is charged in a short time by this on signal, and at that point the on signal is input to the timer circuit 23, so that the ultrasonic sensor 10 There is almost no delay from the negative output to the operation of the hand dryer 1, and the operating characteristics of the hand dryer 1 are improved compared to the conventional control device in which a large-capacity capacitor 50 is provided in the front stage of the amplifier circuit 46 shown in FIG. can be improved. [Second Embodiment] Next, a second embodiment embodying the second invention will be described with reference to FIG. Here, the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted. The hand dryer control device of the second embodiment eliminates the capacitor 29 after the determination circuit 22 in the first embodiment, and also removes the timer circuit 23 constituting the drive control means.
The difference is that an electromagnetic relay 33 is provided between the transistor 32 and the triac 13 as a switch means, as a relay means for electrically separating the two.
The other configurations are the same. That is, a relay coil 33a is connected to the transistor 32, and a contact 33b is connected to the triac 13. When the transistor 32 is turned on based on the on signal from the timer circuit 23, the relay coil 33a is excited and the contact 33b is closed. As a result, the triac 13 turns on, and the motor 4 and heater 7 switch to AC10.
It is powered by a 0 volt power source and hot air is blown out from the hot air outlet 3C toward the hand. In this way, in this second embodiment, the timer circuit 23 constituting the drive control means and the triac 13 as the switch means are mechanically interlocked by the TM relay 33 and electrically separated, so that they can be connected to the same outlet. High voltage noise generated in the same AC power supply such as the above does not enter the control circuit 11, and malfunctions of the control circuit 11 can be prevented. Furthermore, in this second embodiment, by removing the capacitor 29 after the determination circuit 22 in the first embodiment,
Judgment circuit 22 based on hand detection by ultrasonic sensor 10
The hand dryer 1 can be operated in synchronization with the output of the on-signal from the hand dryer 1, and the operating characteristics of the hand dryer 1 can be further improved. [Effects of the Invention] As described in detail above, according to the present invention, it is possible to reliably prevent malfunction of the hand dryer due to noise from the AC power supply.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a first embodiment embodying the first invention, FIG. 2 is an exploded perspective view showing the main parts of a hand dryer,
FIG. 3 is an electric circuit diagram of a second embodiment embodying the second invention, and FIG. 4 is an electric circuit diagram of a conventional example. In the figure, 4 is the motor, 7 is the heater, 3c is the hot air outlet, 1
3 is a tritic as a switch means, 10 is an ultrasonic sensor, 11 is a control circuit as a drive control means, 29 is a capacitor as a noise-on signal absorbing means, and 33 is a relay. Patent applicant Nippondenso Co., Ltd. Inasoku Co., Ltd.

Claims (1)

[Scope of Claims] 1. A heater that is driven by an AC power source and heats air; and a blower fan that is also driven by an AC power source and blows air to the heater and blows out warm air from a hot air outlet. and a switch means for supplying AC power to the heater and the blower fan, the hand dryer comprising: an ultrasonic sensor for detecting a hand placed on the hot air outlet side of the hot air outlet; drive control means that compares the detection signal with a reference voltage and outputs an on signal for causing the switch means to perform an AC power-on operation when the detection signal is large; and between the drive control means and the switch means. 1. A hand dryer control device comprising: noise-on signal absorbing means interposed therein, which absorbs, among the on-signals of the drive control means, an on-signal based on noise intruding from an AC power supply. 2. A heater that is driven by an AC power source and heats the air; A blower fan that is also driven by an AC power source and blows air to the heater and hot air from the hot air outlet; A hand dryer equipped with a heater and a switch means for turning on the blower fan, comprising: an ultrasonic sensor for detecting a hand placed on the hot air outlet side of the hot air outlet; and a detection signal from the ultrasonic sensor and a reference voltage. drive control means that outputs an on signal when the detection signal is large; and a drive control means that is provided between the drive control means and the switch means so as to electrically isolate them; 1. A hand dryer control device comprising: relay means for causing the switch means to perform an alternating current power-on operation based on an on signal from the hand dryer control device.