JPS638325Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] This invention is a low-voltage electric device that uses a manual switch to switch the internal circuit between a high-voltage circuit and a low-voltage circuit depending on the level of the power supply voltage. Relating to a power supply voltage display device for electrical equipment that displays when a high voltage is applied as the power supply voltage when a circuit for use is selected, thereby allowing the operator to select the correct internal circuit for the power supply voltage. It is.

[Background technology]

BACKGROUND ART In recent years, the number of people traveling overseas has increased, and electric appliances such as hair dryers and electric razors are increasingly being used both domestically and internationally. In general, the voltage of commercial power supplies in Japan and overseas is either a low voltage of 100 to 120V or a high voltage of 200 to 240V.In order to use electrical equipment, the internal circuits must be connected to high or low power supply voltages. It is necessary to switch so that either the low voltage circuit or the high voltage circuit is selected correspondingly. However, when this switching is performed using a manual switch, the supplied power supply voltage may be unknown or the internal circuit may be forgotten to switch, and when the low voltage circuit is selected, When a high voltage is applied as the power supply voltage, an overvoltage may occur and cause a failure in the internal circuit.

[Purpose of invention]

The present invention has been developed in view of the above-mentioned problems, and its main purpose is that when a high voltage is applied as the power supply voltage when a low voltage circuit is selected, The object of the present invention is to display the information to alert a person operating the electrical equipment, thereby preventing misuse of the electrical equipment.

[Disclosure of invention]

The present invention is an electrical device that uses a manual switch to switch its internal circuit between a high voltage circuit and a low voltage circuit depending on the level of the power supply voltage. In addition to providing a display circuit that lights up the lamp, when the low voltage circuit is selected, the power supply voltage is applied to this display circuit. A structure that allows voltage to be determined is disclosed.

Embodiments of the present invention will be described below based on the drawings. The voltage display device for electrical equipment according to the present invention is suitable for use in electrical equipment in which an internal circuit 1 is selectively switched between a high voltage circuit and a low voltage circuit using a manual switch 2 depending on the level of the power supply voltage. The display circuit 4 has a display circuit 4 that lights up the lamp 3 at a predetermined voltage between voltages, and the display circuit 4 includes a voltage divider circuit in which a pair of resistors R ₁ and R ₂ are connected in series, and one resistor R constituting the voltage divider circuit. ₁ and _R2 , and a lamp 3, such as a neon lamp, is turned on when the terminal voltage exceeds a predetermined voltage.The display circuit 4 is connected in parallel to a low voltage circuit. In this embodiment, an example is shown in which the electric device is a hair dryer.

FIG. 1 is a circuit diagram showing an embodiment, and an internal circuit 1 includes heaters H ₁ , H ₂ , H ₃ , a motor M, and the like. The first and second heaters H ₁ and H ₂ are connected in series, and a motor M is connected in parallel to the second heater H ₂ . The third heater _H3 is the first and second heater
A switch 2 is used to switch between a series connection state and a parallel connection state with respect to a series circuit composed of H ₁ and H ₂ . The switch 2 is composed of two interlocking changeover switches SW ₁ and SW ₂ . 1st, 2nd,
A common contact of the first changeover switch SW 1 is connected to one end on the third heater H ₃ side of a series circuit in which the third heaters H ₁ , H ₂ , and H ₃ are connected in series, and the first heater H ₁ of the series circuit is connected to one end on the third heater H ₃ side. One side of the power supply is connected to one end of the side. The other side of the power supply is connected to the common contact of the second changeover switch _SW2 . If the changeover switches SW ₁ and SW ₂ are turned on to one contact side, the first changeover switch SW ₁
One end of the first heater H 1 side and the _third heater H ₃ of the series circuit composed of heaters H ₁ , H ₂ , and H ₃ are connected via a
One end of the side is connected and one side of the power supply is connected here, and the second heater H ₂ and the third heater H ₃
The other end of the power supply is connected to the intermediate point between the two terminals via the second changeover switch _SW2 . That is, the series circuit including the first and second heaters H ₁ and H ₂ and the third heater H ₃ are connected in parallel to the power supply. Changeover switch SW ₁ ,
If SW ₂ is applied to the other contact side, heater H ₁ ,
A power supply is connected to both ends of the series circuit composed of H ₂ and H ₃ via changeover switches SW ₁ and SW ₂ . The changeover switches SW ₁ and SW ₂ can be held in an intermediate position in which neither contact is closed, and at this time the heaters H ₁ , H ₂ and H ₃ are turned off.
By changing the connection of the heaters H ₁ , H ₂ , H ₃ using the changeover switches SW ₁ and SW ₂ in this way, when the power supply voltage is high, the heaters H ₁ , H ₂ , and H ₃ are connected in series. When the power supply voltage is low, heater H ₁ ,
By connecting a portion of H ₂ and H ₃ in parallel, the voltage between both terminals of the motor M is kept approximately constant. A temperature fuse F and a thermoswitch T are connected in series between the above circuit and the power supply, and heaters H ₁ , H ₂ ,
When H ₃ becomes overheated, the heaters H ₁ , H ₂ , H ₃
Risks such as fire can be prevented by cutting off the supply of power voltage to the

An indicator circuit 4 is connected between the low-voltage contact of the second switch _SW2 and one end of the power supply. The indicator circuit 4 is composed of two voltage-dividing resistors _R1 and _R2 that divide the power supply voltage, and a lamp ₃ connected in parallel to one of the voltage-dividing resistors R2. A neon lamp is used as the lamp 3. A neon lamp lights up at a predetermined terminal voltage, and its lighting voltage is approximately stable. The voltage-dividing resistors _R1 and _R2 are set so that when the applied power supply voltage is a high voltage of 200 to 240 V, the voltage drop of one of the voltage-dividing resistors _R2 is equal to or higher than the lighting voltage of the lamp 3, and when the power supply voltage is a low voltage of 100 to 120 V, the voltage drop is equal to or lower than the extinguishing voltage of the lamp 3. With the above configuration, when the low-voltage circuit is selected by the switch 2, the power supply voltage is applied to the indicator circuit 4, and in this state, if the power supply voltage is high, the lamp 3 lights up, and if the power supply voltage is low, the lamp 3 goes out. On the other hand, when the high voltage circuit is selected by switch 2, the voltage applied to display circuit 4 is divided by heaters _H1 , _H2 , and _H3 , so lamp 3 does not light up regardless of the level of the power supply voltage. By operating as described above, if a high voltage is mistakenly applied when the low voltage circuit is selected, lamp 3 lights up to warn the user, thereby preventing overvoltage from being applied to the internal circuits of motor M, etc.

FIG. 2 shows a hair dryer equipped with the above-mentioned circuit. The motor M and heater H are housed in a cylindrical housing 5.
The housing 5 is disposed substantially in a straight line along the axis of the housing 5. The motor M is a DC motor, and a power supply voltage divided by a heater H is applied to the motor M via a rectifier 7. A fan 6 is attached to the output shaft 8 of the motor M, and rotation of the fan 6 generates a flow of air from the motor M side toward the heater H side along the axis of the housing 5. A switch storage section 12 is formed at one location on the periphery of the housing 5, and within the switch storage section 12, two changeover switches SW ₁ and SW ₂ are arranged side by side along the axis of the housing 5. The operating levers 9 of these changeover switches SW ₁ and SW ₂ are connected to a connecting plate 11 that integrally extends from a switch operating plate 10 exposed on the outer periphery of the switch housing 12.
When the switch operation plate 10 is moved in the vertical direction in FIG. 2, both the changeover switches SW ₁ and SW ₂ are interlocked. The changeover switches SW ₁ and SW ₂ correspond to a low voltage when the switch operation plate 10 is moved upward, a high voltage when moved downward, and are turned off at an intermediate position. By the way, since the switch operation plate 10 is capable of switching between high and low voltages, there is a high possibility of erroneous operation. Therefore, a voltage lock lever 13 is provided below the switch operation plate 10 so that the switch operation plate 10 can be moved only to either the high voltage side or the low voltage side. The voltage lock lever 13 is connected to the housing 5
One end portion is exposed on the outer periphery, and the other end portion is held by a guide rib 14 provided within the housing 5 and having a substantially U-shaped cross section. The connecting plate 11 is arranged between the guide rib 14 and the outer circumferential wall of the housing 5, and has a zigzag-shaped slide hole 1 provided in the connecting plate 11.
The center portion of the voltage lock lever 13 is inserted into the hole 5. Further, the voltage lock lever 13 is mounted so as to be movable in the left and right directions in FIGS. 3 and 4.
That is, as shown in FIG. 6, the slide hole 15 has a portion in the center in the longitudinal direction that has a width that allows the voltage lock lever 13 to move left and right, and the hole extends upward from the left half of that portion. At the same time, a hole extends downward from the right half. However, when the voltage lock lever 13 moves to the left, the connecting plate 11 can only move downward from the neutral position, and when the voltage lock lever 13 moves to the right, the connecting plate 11 can only move upward from the neutral position. Thereby, by holding the voltage lock lever 13 in either the left or right position, the switch operation plate 10 can be moved to either the low voltage or the high voltage. As described above, if the voltage lock lever 13 is moved to the corresponding position after confirming the power supply voltage by blinking the lamp 3, the switch operation panel 10
moves only in the direction corresponding to the power supply voltage, thereby preventing erroneous operation. The voltage lock lever 13 is located within the switch housing 12.
An elastic L-shaped arm 17 extends left and right, and a protrusion 18 is formed on the inner peripheral surface of the switch storage portion 12 corresponding to the tip of the arm 17. However, when the voltage lock lever 13 moves from side to side, a click occurs due to the arm 17 and the protrusion 18. A name plate 19 is attached to the outer peripheral surface of the switch storage portion 12 on which characters corresponding to the switch operation plate 10, voltage lock lever 13, lamp 3, etc. are displayed. A lamp cover 20 is attached to one place on the name plate 19 in correspondence with the lamp 3.

[Effect of idea]

As mentioned above, the present invention provides an electric device that selectively switches its internal circuit between a high voltage circuit and a low voltage circuit depending on the level of the power supply voltage using a manual switch. The display circuit has a display circuit that lights up a lamp, and the display circuit is a voltage divider circuit consisting of a pair of resistors connected in series, and is connected in parallel to one of the resistors making up the voltage divider circuit, and lights up when the terminal voltage exceeds a predetermined voltage. The display circuit is connected in parallel to the low-voltage circuit, and when the low-voltage circuit is selected, when a high voltage is applied as the power supply voltage, the display circuit is connected in parallel to the low-voltage circuit. The lamp lights up and turns off when a low voltage is applied as the power supply voltage, so when a high voltage is applied as the power supply voltage to the low voltage circuit, the lamp lights up to alert the operator. However, this has the advantage that misuse of electrical equipment can be prevented. The display circuit is composed of a voltage dividing resistor that divides the power supply voltage, and a neon lamp-like lamp that is connected in parallel to one of the voltage dividing resistors and lights up when the terminal voltage exceeds a predetermined voltage. Since the circuit is simple and the number of components is small, the impedance of the lamp is high especially when using a neon lamp as a lamp, so a high resistance voltage dividing resistor can be used. As a result, the current flowing through the resistor becomes smaller, resulting in less heat generation from the resistor.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a longitudinal cross-sectional view of a hair dryer using the same as above.
The figure is a front view of the switch housing section in Figure 2, Figure 4 is a sectional view taken along the line X--X in Figure 2, and Figure 5 is a cross-sectional view taken along the line Y--
6 is a sectional view taken along the line Z--Z in FIG. 4. 1 is the internal circuit, 2 is the switch, 3 is the lamp, 4
is a display circuit, and R ₁ and R ₂ are voltage dividing resistors.

Claims (1)

[Scope of utility model registration request] In electrical equipment whose internal circuit is selectively switched between a high-voltage circuit and a low-voltage circuit according to the level of the power supply voltage, an indicator circuit is provided that lights up a lamp at a predetermined voltage between the above-mentioned high and low voltages. The display circuit consists of a voltage divider circuit consisting of a pair of resistors connected in series, and a neon lamp-like lamp that is connected in parallel to one of the resistors forming the voltage divider circuit and lights up when the terminal voltage exceeds a predetermined voltage. A voltage display device for electrical equipment in which the display circuit is connected in parallel to a low voltage circuit.