WO2003088277A1

WO2003088277A1 - Portable electric device for adjusting a variable resistor

Info

Publication number: WO2003088277A1
Application number: PCT/KR2002/002315
Authority: WO
Inventors: Hyeong Ki Cho
Original assignee: Imt Co., Ltd.
Priority date: 2002-04-08
Filing date: 2002-12-09
Publication date: 2003-10-23
Also published as: KR100345616B1; AU2002367873A1

Abstract

A portable electric device for adjusting a variable resistor includes a cylindrical main body having an opening at one end thereof; a battery disposed inside the main body; a motor for providing a torque; a reducer for reducing a rotational speed of the motor; a rotation tip coupled to a shaft of the reducer; a printed circuit board having circuits for varying the rotational direction and speed of the motor; a clockwise driving switch and a counterclockwise driving switch for rotating the motor in a clockwise or a counterclockwise direction, respectively; and a speed adjusting knob for varying the rotational speed of the motor. Such device, while being compact and portable, employs torque applied by the motor, which is decelerated by the reducer, thereby facilitating precise control of the variable resistor.

Description

PORTABLE ELECTRIC DEVICE FOR ADJUSTING A VARIABLE RESISTOR

Technical Field

The present invention relates to a portable electric device for adjusting a variable resistor; and, more particularly, to a portable electric device capable of conveniently and precisely adjusting resistance of a variable resistor.

Background Art

Generally, it is required to appropriately adjust resistance of a variable resistor installed in electric and electronic devices. It is meaningless to control the resistance of the variable resistor in an offline state, i.e., in a state wherein a measuring device is not connected to the variable resistor. Thus, in an online state, an operator should adjust the resistance of the variable resistor to an appropriate value while monitoring the measuring device. In specific applications, a robot is used for adjusting the variable resistor. However, such robot is expensive .

Accordingly, in most industrial fields, an operator directly rotates a control knob of the variable resistor in a state that equipments such as a tester or an oscilloscope are connected with the variable resistor. The operator uses a screwdriver to adjust the variable resistor. However, the operator becomes distressed by repeated operations of rotating the control knob of the variable resistor, thereby resulting in deterioration of the operating efficiency.

In case an electric screwdriver operated by a motor is used for rotating the control knob of the variable resistor, a rotational speed of the electric screwdriver makes it difficult to accurately rotate the control knob of the variable resistor, so that the variable resistor cannot be precisely adjusted. Further, an excessive rotation may damage the control knob of the variable resistor. Accordingly, the electric screwdriver is practically not usable. In addition, the electric screwdriver exerting torque required to rotate a screw or bolt is large and heavy, and therefore, it is difficult to carry it and to use it for an operation requiring accuracy, e.g., for adjusting the control knob of the variable resistor.

Disclosure of Invention

It is, therefore, an object of the present invention to provide a portable electric device for adjusting a variable resistor, wherein a rotational force of a motor is decreased by a reducer and an adjustment of the variable resistor can be precisely and automatically carried out, so that resistance of the variable resistor can be conveniently and accurately adjusted and wherein the rotational speed of the motor is adjusted so that the control of the variable resistor can be efficiently performed.

In accordance with the present invention, there is provided an apparatus for rotating a rotating knob of a variable resistor, the apparatus including: a cylindrical main body having an opening at one end thereof; a battery disposed inside the main body; a motor disposed inside the main body and receiving power from the battery; a reducer installed inside the main body, for reducing a rotational speed of the motor; a rotation tip coupled to a shaft of the reducer to be disposed at one end of the main body, an end of the rotation tip being inserted into a rotating knob of the variable resistor; a printed circuit board (PCB) installed inside the main body and having circuits for applying power of the battery to the motor and varying the rotational speed and a rotational direction of the motor; a clockwise and a counterclockwise driving switch connected to the PCB and disposed outside the main body, for rotating the motor in a clockwise and a counterclockwise direction, respectively; and a speed adjusting knob connected to the PCB and disposed outside the main body, for varying the rotational speed of the motor.

Brief Description of Drawings

The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with accompanying drawings, in which:

Fig. 1 shows a front view of a portable electric device for adjusting a variable resistor; and

Fig. 2 illustrates a longitudinal cross-section view of the portable electric device for adjusting a variable resistor .

Best Mode for Carrying Out the Invention

' Hereinafter, a preferred embodiment of a portable electric device for adjusting a variable resistor in accordance with present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a front view of a portable electric device for adjusting a variable resistor. Fig. 2 illustrates a longitudinal cross-section view of the portable electric device for adjusting the variable resistor. As can be seen from Figs. 1 and 2, the portable electric device for adjusting the variable resistor in accordance with the present invention includes a cylindrical main body 10 having an opening 11 at one end thereof, a battery 20 disposed inside the main body 10, a motor 30 disposed inside the main body 10 and receiving power from the battery 20, a reducer 40 installed inside the main body 10, for reducing a rotational speed of the motor 30 to 20-90 rpm, a rotation tip 50 coupled to a shaft of the reducer 40 and installed at one end of the main body 10, an end of the rotation tip 50 inserted into a rotating knob (not illustrated) of a variable resistor (not illustrated) to thereby rotate the rotating knob, a printed circuit board (PCB) 60 installed inside the main body 10 and having circuits for applying power from the battery 20 to the motor 30 and changing a rotational direction and speed of the motor 30, a clockwise driving switch 61 and a counterclockwise driving switch 62 disposed outside the main body 10, for rotating the motor in a clockwise and a counterclockwise direction, respectively, and a speed adjusting knob 63 installed outside the main body 10, for adjusting the rotational speed of the motor.

The approximately cylindrical main body 10 having a certain length is formed with a portable pen shape for a convenient possession thereof. A protection cap 12 is detachably fitted on one end of the main body 10 where the opening 11 is formed.

The protection cap 12 may be detached from the end of the main body 10 and then mounted on a mounting portion 13 formed at the other end of the main body 10 while the device adjusts the output of the variable resistor. The battery 20 used in the portable electric device for adjusting a variable resistor in accordance with a preferred embodiment of the present invention is a rechargeable battery, and preferably, is a nickel-hydrogen battery. Further, a nickel-cadmium battery, a nickel-ion battery, or a conventional disposable battery can be used. In this case, a desirable voltage of the battery is approximately 7.2 V.

A jack 21 for charging the battery 20 is provided at the end of the main body 10 near the battery 20 and power from an external power adaptor is applied to the jack 21 to charge the rechargeable battery 20. Further, a connection groove 21a of the charging jack 21 is formed through the mounting portion 13 of the main body 10.

The motor 30 is operated by power applied from the battery 20. The reducer 40 proportionately reduces a rotational speed of the motor 30. The motor 30 has a rated voltage of 4.5 V and a rated current of 80-120 πiA. A rated revolution per minute (rpm) of the reducer 40 driven by the motor 30 is about 54 rpm (upon DC 4.5 V), and the rpm of the reducer 40 may vary in range of about 20-90 rpm depending on the voltage applied to the motor 30.

Preferably, the rotational speed decreased by the reducer 40 is less than about 50 rpm in order to precisely and effectively rotate a rotating knob of a variable resistor. Moreover, it is preferred that torque of a shaft of the reducer 40 is less than about 500 gf ^■ cm in order to safely rotate the rotating knob of the variable resistor.

The rotation tip 50 is installed at one end of the main body 10 by coupling it to the shaft of the reducer 40, to thereby rotate the rotating knob of the variable resistor by using the rotational force decreased by the reducer 40.

Further, the rotation tip 50 includes a holder 51 and a tip 52. The holder 51 made of, e.g., plastic material, is inserted into the opening 11 of the main body 10 and then coupled to the shaft of the reducer 40. The tip 52 made of material such as metal or ceramic is inserted into an insertion groove of the holder 51. In use, the tip 52 is coupled with the rotating knob of the variable resistor. Such rotation tip 50 may also be used for assembling and dissembling other devices, which requires small torque, depending on its shape and usage.

In case a groove (not illustrated) is formed at the rotating knob of the variable resistor, an end of the tip 52 has a cross-sectional shape corresponding to that of the groove, e.g., a cross or linear shape so that the tip can be fitted in the groove for rotating the rotating knob of the variable resistor. Further, if a line-shaped groove is formed at the rotating knob of the variable resistor, a guide may be provided to a line-shaped tip in order to prevent the line-shaped tip from being separated from the rotating knob of the variable resistor during an adjustment of the variable resistor.

On the other hand, in case a protrusion (not shown) is formed at the rotating knob of the variable resistor, the insertion groove of the holder 51 is formed with a shape corresponding to that of the protrusion so that the insertion groove can fit on the protrusion of the rotating knob. Thus, the protrusion of the rotating knob is inserted into the insertion groove of the holder 51 with the tip 52 detached, so that the rotating knob of the variable resistor can be rotated.

The PCB 60 installed inside the main body 10 has circuits for providing power from the battery 20 to the motor 30 and varying the rotational direction and speed of the motor 30. Mounted on a top portion of the PCB 60 are a clockwise driving switch 61, a counterclockwise driving switch 62 and a speed adjusting knob 63. Further, the PCB 60 is provided with a chip for interrupting current applied to the motor 30 when it is overloaded. Each of the clockwise driving switch 61, the counterclockwise switch 62 and the speed adjusting knob 63 is outwardly protruded from the main body 10. By operating the clockwise driving switch 61 and the counterclockwise driving switch 62, the motor 30 can be rotated in a clockwise and a counterclockwise direction, respectively. The speed adjusting knob 63 controls the rotational speed of the motor 30.

Further, the speed adjusting knob 63 is formed in a wheel shape, and therefore, an operator can rotate the speed adjusting knob 63 in a clockwise or counterclockwise direction. Accordingly, the rotational speed of the motor 30 can be increased or decreased as described.

The operation of the portable electric device for adjusting the variable resistor will now be described. In order to adjust resistance of the variable resistor, the tip 52 of the rotation tip 50 is coupled with the rotating knob of the variable resistor. Then, the motor 30 is rotated in a clockwise or counterclockwise direction by pushing the clockwise driving switch 61 or the counterclockwise driving switch 62, thereby rotating the rotation tip 50. Next, the speed adjusting knob 63 is adjusted for precisely rotating the rotating knob of the variable resistor at an appropriate speed.

In case a groove is formed at the rotating knob of the variable resistor, the end of the tip 52 inserted into the holder 51 is fitted into the groove of the rotating knob, for rotating the rotating knob. On the other hand, if a protrusion is formed at the rotating knob of the variable resistor, the tip 52 is removed from the holder 51. Next, the insertion groove of the holder 51 is fitted onto the protrusion of the rotating knob, for rotating the rotating knob.

Further, the motor 30 is rotated in a clockwise or counterclockwise direction by pushing the clockwise driving switch 61 or the counterclockwise driving switch 62. If both switches 61 and 62 are simultaneously pushed, the motor is stopped.

Since the main body 10 is formed as a pen shape, it can be conveniently carried. The protection cap 12 that is detachable from the main body 10 protects the rotation tip 50 from a possible external impact.

As described above, in accordance with the preferred embodiment of the present, since the rotational force of the motor is decreased by the reducer and the adjustment of the variable resistor can be precisely and automatically carried out, the resistance of the variable resistor can be conveniently and accurately adjusted. Further, since the rotational speed of the motor can be adjusted, the control of the variable resistor is efficiently performed. While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. An apparatus for rotating a rotating knob of a variable resistor, the apparatus comprising: a cylindrical main body having an opening at one end thereof; a battery disposed inside the main body; a motor disposed inside the main body and receiving power from the battery; a reducer installed inside the main body, for reducing a rotational speed of the motor; a rotation tip coupled to a shaft of the reducer to be disposed at one end of the main body, an end of the rotation tip being inserted into a rotating knob of the variable resistor; a printed circuit board (PCB) installed inside the main body and having circuits for applying power of the battery to the motor and varying the rotational speed and a rotational direction of the motor; a clockwise and a counterclockwise driving switch connected to the PCB and disposed outside the main body, for rotating the motor in a clockwise and a counterclockwise direction, respectively; and a speed adjusting knob connected to the PCB and disposed outside the main body, for varying the rotational speed of the motor.

2. The apparatus of claim 1, wherein the main body is formed as a pen shape and has a detachable protection cap at the end thereof.

3. The apparatus of claim 1, wherein the battery is rechargeable, and a jack for charging the battery is provided at one end of the main body, power from an external power adaptor being applied to the jack to charge the rechargeable battery.

4. The apparatus of claim 1, wherein the rotation tip includes a holder fixed into an opening of the main body and a tip of which an end is inserted into the rotating knob of the variable resistor, wherein the tip is coupled with an insertion groove formed in the holder.

5. The apparatus of claim 1, wherein the rotation tip includes a guide for preventing the rotation tip from being separated from the rotating knob of the variable resistor.