JPS637124Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] This invention relates to improvements in hair dryers.

[Technical background of the invention and its problems]

Conventionally, hair dryers have been equipped with a power switch and a micro switch or touch switch on the handle to detect hand contact with the handle. What is possible is known. By doing this, it is possible to prevent accidents such as fires and burns caused by forgetting to turn off the power switch.

However, devices that use micro switches have a high failure rate because they are mechanical contacts, and devices that use touch switches have short lifespans because current flows through the electrodes, making them susceptible to damage due to electrolysis or rust. It had some flaws. In particular, hair dryers are often used in extremely humid environments such as bathrooms and washrooms, so if you use the aforementioned micro switches or touch switches, moisture may adhere to the contacts, causing malfunctions and electric shocks. Accidents were becoming more likely to occur, and improvements were desperately needed from a safety standpoint. In addition, the contact points are likely to be corroded due to moisture adhesion, which may further accelerate the reduction in service life.

[Purpose of invention]

This invention was devised to eliminate these drawbacks, and the purpose is to provide a hair dryer that can improve safety and extend its lifespan.

[Summary of the idea]

This device houses a capacitance sensing circuit inside the hair dryer body that senses the capacitance that changes due to the proximity of the human body, and uses the capacitance sensing output of the capacitance sensing circuit to detect the heating element and the fan. This makes it possible to supply power to the motor.

[Example of idea]

In FIG. 1, reference numeral 1 denotes a hair dryer body comprising a cylindrical portion 2 and a handle 3 attached to the lower part thereof. An air outlet 4 is provided at the tip of the cylindrical portion 2 of the hair dryer main body 1.
An intake port 5 is provided at the rear end, and a heating element 6 and a fan motor 7 are housed inside the cylindrical portion 2. A power switch mechanism 8 is attached to the case portion of the handle 3, and a capacitance sensing circuit 9 is housed within the handle 3. The capacitance sensing circuit 9 has a pair of lead wires 10a and 10b attached along the inner wall of the case portion of the handle 3.

Figure 2 shows the circuit configuration.
The capacitance sensing circuit 9 is connected to the capacitance sensing circuit 9 via a first power switch 8. In addition, the AC power source 11
and the first power switch 8a, the normally open side of the switching contact 12 of the output relay described later, and the limiter 13.
A series circuit of the second power switch 8b and the heat generating element 6 is connected through a series circuit, and an input terminal of a full-wave rectifying diode bridge circuit 15 is further connected through a voltage drop resistor 14. . The fan motor 7 is connected to the output terminal of the diode bridge circuit 15. The capacitance sensing circuit 9 connects the input terminal of a full-wave rectifying diode bridge circuit 17 to the AC power supply 11 via a first power switch 8a and a resistor 16, and connects the input terminal of the diode bridge circuit 17 to the AC power supply 11. The input terminal of the smoothing circuit 18 is connected to the input terminal of the smoothing circuit 18. Said smoothing circuit 1
An output relay 20 is connected to the output terminal of 8 through an NPN transistor 19, and a Zener diode 22 is connected through a resistor 21 to form a constant voltage power source. A positive terminal of the Zener diode 22 is connected to an input terminal of an inverter 24 via a resistor 23. The input terminal of the inverter 24 is also connected to the output terminal of an oscillation circuit 41 via a capacitor 25. The oscillation circuit 4
1 connects two inverters 26 and 27 in series, connects a series circuit of resistors 28 and 29 between the output terminal and input terminal of the inverter 26, and connects the connection point between the resistors 28 and 29 with a capacitor. It is connected to the output terminal of the inverter 27 via the inverter 30. The output terminal of the inverter 24 is connected to the input terminal of the inverter 32 via a diode 31, and further connected to the Zener diode 2 via a resistor 33 and a semi-fixed resistor 34 in series.
It is connected to the negative terminal of No.2. and the resistor 3
One ends of the lead wires 10a and 10b are connected to both ends of a series circuit consisting of a semi-fixed resistor 3 and a semi-fixed resistor 34, respectively. The output terminal of the inverter 32 is connected to the input terminal of an AC amplifier circuit 42 via a resistor 35. The AC amplifier circuit 42 includes two inverters 3
6 and 37 are connected in series, a capacitor 38 is connected between the input terminal of the inverter 36 and the negative terminal of the Zener diode 22, and between the input terminal of the inverter 36 and the output terminal of the inverter 37. A feedback resistor 39 is connected to the resistor 39. The output terminal of the amplifier circuit 42 is connected to the base of the transistor 19 via a resistor 40. The first and second power switches 8a and 8b are turned off by the switch mechanism 8, only the first power switch 8a is turned on (cold air operation), and both are turned on (warm air operation).
It changes as the street changes.

In the embodiment of the present invention constructed in this way, the first and second
The power switches 8a and 8b operate in three ways, and the first power switch 8 operates during cold air and hot air operation.
a is turned on. When the first power switch 8a is in the ON state and the handle 3 is grasped by hand, a pair of lead wires 10
The capacitance between a and 10b increases, and the input level to the inverter 32 changes to low level.
In this case, the input level to the inverter 32 is stable because the voltage from the constant voltage power supply and the voltage from the oscillation circuit 41 are superimposed and determined via the inverter 24 and the diode 31. The increase in capacitance between the two leads to a stable low level. As a result, the input level to the AC amplifier circuit 37 becomes high level and exceeds its threshold level, the output of the circuit 37 becomes high level, and the transistor 19 is turned on. When the transistor 19 is turned on, the output relay 20 operates, and the normally open side of the switching contact 12 thereof is closed. Thus, the fan motor 7 operates. Furthermore, if the second power switch 8b is on, the heating element 6 also operates. As the fan motor 7 and the heating element 6 operate in this manner, hot air is discharged from the air outlet 4, and the fan motor 7
Cold air is discharged from the air outlet 4 by the operation of the chisel.

When you release your hand from the handle 3 during such warm air or cold air operation, the pair of lead wires 10
The capacitance between a and 10b disappears, and the input level to the inverter 32 returns to high level. As a result, the input level to the AC amplifier circuit 42 falls below its threshold level, the output level of the circuit 42 becomes low level, and the transistor 19 is turned off. This deenergizes the relay 20, opens the normally open side of its switching contact 12, and closes its normally closed side. Thus, the current supply path to the heating element 6 and fan motor 7 is cut off. Therefore, even if the first and second power switches 8a and 8b are left on, the heating element 6 and fan motor 7 will not continue to operate. Therefore, there is no risk of accidents such as fire or burns occurring, and safety can be improved. Moreover, a pair of lead wires 10a attached to the inner wall of the handle 3 prevents the hand from touching the handle 3.
Since it detects by sensing the increase in capacitance between 10b and 10b, the failure rate is extremely low compared to those using mechanical contacts, and compared to those using touch switches, there is no direct shaking of the hand. No current flows through the lead wires, and the lead wires are not damaged by electrolysis or rust. Therefore, it is possible to improve the lifespan. In addition, since it does not use mechanical contacts, it will not cause electrical leakage even if used in extremely humid places such as bathrooms and washrooms.
It is possible to prevent safety-related accidents such as electric shock from occurring.

In addition, in the above-mentioned example, a pair of lead wires were attached to the inner wall of the handle, but the invention is not limited to this. For example, one of the lead wires is installed near the air outlet, and the handle is attached to the inner wall of the handle. It may also be possible to detect changes in capacitance when the device is brought close to the head.

[Effect of idea]

As described above, according to this invention, it is possible to provide a hair dryer that can improve safety and further extend its life.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional schematic diagram showing an embodiment of this invention, and FIG. 2 is a circuit diagram of the same embodiment. 1...Hair dryer body, 3...Handle, 4
...Blower port, 5...Intake port, 6...Heating element, 7...
...Fan motor, 8...Power switch mechanism, 9...
...Capacitance sensing circuit, 10a, 10b...Lead wires.

Claims (1)

[Scope of utility model registration request] A hair dryer body with an air outlet at the tip, an air intake at the rear end, a heating element and a fan motor housed inside, and a power switch attached to the case;
It is characterized by being equipped with a capacitance sensing circuit that senses a change in capacitance and controls opening/closing of a circuit formed by connecting the heating element and the fan motor to a power source via the power switch. hair dryer.