KR20130058155A - Pwm frequency self control device and method for removing noise - Google Patents

Pwm frequency self control device and method for removing noise Download PDF

Info

Publication number
KR20130058155A
KR20130058155A KR1020110124014A KR20110124014A KR20130058155A KR 20130058155 A KR20130058155 A KR 20130058155A KR 1020110124014 A KR1020110124014 A KR 1020110124014A KR 20110124014 A KR20110124014 A KR 20110124014A KR 20130058155 A KR20130058155 A KR 20130058155A
Authority
KR
South Korea
Prior art keywords
pwm
frequency
power supply
oscillation frequency
receiver
Prior art date
Application number
KR1020110124014A
Other languages
Korean (ko)
Inventor
어동수
Original Assignee
현대모비스 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 현대모비스 주식회사 filed Critical 현대모비스 주식회사
Priority to KR1020110124014A priority Critical patent/KR20130058155A/en
Publication of KR20130058155A publication Critical patent/KR20130058155A/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/08—Duration or width modulation ; Duty cycle modulation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M5/00—Conversion of the form of the representation of individual digits
    • H03M5/02—Conversion to or from representation by pulses
    • H03M5/04—Conversion to or from representation by pulses the pulses having two levels
    • H03M5/06—Code representation, e.g. transition, for a given bit cell depending only on the information in that bit cell
    • H03M5/08—Code representation by pulse width
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference

Abstract

PURPOSE: A PWM(Pulse Width Modulation) frequency control device for eliminating noise and a method thereof are provided to eliminate mutual interference noise when a reception frequency and a PWM oscillating frequency are in an integer ratio. CONSTITUTION: A reception unit(210) receives an electric wave including image information or sound information. A PWM power supply unit(220) generates or supplies power with a PWM oscillating frequency. A ground circuit(230) includes a transistor and one or more resistances. A count unit(240) counts the oscillating frequency of the PWM power. When the reception frequency of the reception unit is n*f or 1/2n*f, a microcomputer(250) activates the transistor. [Reference numerals] (200) PWM frequency self-control device; (210) Reception unit; (220) PWM power supply unit; (230) Ground circuit; (240) Count unit; (250) Microcomputer; (260) Harmonic wave filter unit

Description

PWM frequency self control device and method for removing noise

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency self-controlling apparatus and a method, and more particularly, to a PWM (Pulse Width Modulation) frequency for noise cancellation based on harmonic / harmonic components of an oscillation frequency of a receiver and a power supply for receiving radio waves such as radios and TVs. A self control device and method are disclosed.

1 is a block diagram of a conventional receiver system.

In the receiver system 100 using the PWM power supply IC, the PWM power supply IC 130 supplies power through the set resistance of the oscillation frequency. When the reception frequency of the receiver 110 coincides with an integer multiple of the oscillation frequency of the PWM power supply IC 130, harmonics occur to generate heat and noise in the receiver system 100. Therefore, by adding transistor circuits 140, 150, and 160 that can change the oscillation frequency of the PWM power supply IC, the microcomputer 120 activates the transistor when the frequency of the receiver 110 is the same as the oscillation frequency of the PWM power supply IC 130. To solve the harmonics.

The prior art checks the oscillation frequency of the PWM power supply IC 130 of the receiver system 100 and corrects wrong signals and data individually for each reception frequency of the receiver 110, thereby correcting for errors in the resistance and IC circuits, and malfunctioning signals. The detection and data modification of the time-consuming and difficult task.

It is an object of the present invention to provide a PWM frequency self-control device and method which eliminates mutual interference noise caused by harmonic components generated when a reception frequency and a PWM oscillation frequency inside a receiver system for receiving radio waves are integer multiples.

According to an aspect of the present invention, there is provided a pulse width modulation frequency self control device including a receiver configured to receive a radio wave including image information or sound information; A PWM power supply unit for generating / supplying power by the PWM oscillation frequency; A ground circuit composed of a transistor and at least one resistor; A counting unit for counting the oscillation frequency of the PWM power supply; And f is an oscillation frequency of the PWM power supply, n is a natural frequency of 2 or more, the receiving frequency of the receiver is

Figure pat00001
In the case of including a microcomputer to activate the transistor.

Pulse width modulation frequency self-control method according to another aspect of the present invention comprises the steps of obtaining a system key; PWM for generating / supplying power by the control output, PWM oscillation frequency, and PWM oscillation frequency to turn on / off the transistor to be activated when the receiving frequency of the receiver receiving the radio wave including image information or sound information satisfies a predetermined condition. Setting a power supply unit; Counting the PWM oscillation frequency and setting a range of two or more natural numbers n; Determining the PWM oscillation frequency range; And maintaining said control output.

According to the present invention, when the reception frequency of the receiver in the counter becomes an integer multiple of the oscillation frequency of the PWM frequency power supply, the whistle based on the harmonic component is activated by activating the transistor of the ground circuit and changing the oscillation frequency of the PWM frequency power supply. Noise (Whistle Noise) and Beat Noise (Beat Noise) are removed. Therefore, the receiver system is stabilized and heat generation due to harmonic components is reduced, thereby reducing the error rate of the receiver system, and improving the receiver sensitivity and signal to noise ratio (SNR).

1 is a block diagram of a conventional receiver system.
2 is a block diagram of a PWM frequency self control device according to an embodiment of the present invention.
3 is a block diagram of a harmonic filter unit according to an embodiment of the present invention.
4 is a block diagram of a ground circuit according to an embodiment of the present invention.
5 is a flowchart of a PWM frequency self control method according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms " comprises, " and / or "comprising" refer to the presence or absence of one or more other components, steps, operations, and / Or additions.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a PWM self-controlling device according to an embodiment of the present invention.

The PWM self-controlling device 200 includes a receiver 210, a PWM power supply 220, a ground circuit 230, a counter 240, a microcomputer 250, and a harmonic filter 260.

The receiver 210 receives a radio wave including image information or sound information. The PWM power supply 220 generates / supplies power by the PWM oscillation frequency. The ground circuit 230 is positioned at the lower end of the PWM power supply unit 220 and adjusts the PWM oscillation frequency using a transistor and a resistor to prevent harmonics from occurring. The counting unit 240 counts the oscillation frequency of the PWM power supply. The harmonic filter unit 260 filters the harmonic components of the power frequency generated by the PWM power supply unit 220 to prevent harmonics from occurring.

The microcomputer 250 controls input / output of the control signals of the receiver 210, the PWM power supply 220, the ground circuit 230, the counter 240, and the harmonic filter 260, respectively.

3 is a block diagram of a harmonic filter unit 260 according to an embodiment of the present invention.

The harmonic filter unit 260 includes a waveform correction resistor unit 266 and a T filter unit 262. The balance reactor 264 and the discharge resistor unit 268 are included.

The T filter unit 262 includes a balance reactor 264 configured by connecting an inductor and a resistor in series to lower the impedance of a specific order. The waveform correction resistor 266 reduces the impedance of the PWM power supply 220. The discharge resistor unit 268 is connected in series to the ends of the balance reactor 264 of the T filter unit 262 and emits electric charges.

4 is a configuration diagram of a ground circuit 230 according to an embodiment of the present invention.

The ground circuit 230 is connected to the lower end of the PWM power supply 220, and includes a transistor 232 and at least two resistors (eg, 234 and 236). The transistor 232 is activated when the reception frequency of the receiver 210 is an integer multiple of the oscillation frequency of the PWM power supply 220. For example, before the transistor 232 is activated, only one resistor 236 exists in the ground circuit 230, but after activation, two resistors 234 and 236 are connected in parallel to the ground circuit 230.

This will be described in more detail as follows.

The receiver 210 receives a radio wave including image information or sound information. The PWM power supply 220 generates / supplies power by the PWM oscillation frequency. The microcomputer 250 may control the oscillation frequency of the PWM power supply 220. The microcomputer 250 sets the initial state of the transistor 232 to OFF.

When the frequency of the received radio wave of the receiver 210 becomes an integer multiple of the PWM oscillation frequency of the PWM power supply unit 220 or a divisor component divided by an integer multiple of the PWM oscillation frequency, that is, an integer of 2, 3, or 4 times the PWM fundamental frequency. Harmonics / harmonics are generated based on physical quantities corresponding to doublings or divisors divided by 1, ½, ⅓, ¼ integer times. When harmonics / harmonics are generated, heat and noise are generated in the receiver system, and the reception sensitivity is lowered. Therefore, the microcomputer 250 has a reception frequency at the receiver 210.

Figure pat00002
In the case of (f = oscillation frequency), a control signal is transmitted to the counting unit 240. The counting unit 240 counts the frequency input from the PWM power supply unit 220 to the count line
Figure pat00003
Calculate the harmonics / harmonics to the receiving range of the receiving unit 210. The receiving frequency of the receiver 210 is
Figure pat00004
In this case, the counting unit 240 transmits a control signal to the microcomputer 250, and the microcomputer 250 receiving the signal activates the transistor 232 of the ground circuit 230. For example, only one resistor 236 is present in the ground circuit 230 before the transistor 232 is activated, but two resistors 234 and 236 are connected in parallel to the ground circuit 230 after the transistor 232 is activated. Therefore, the oscillation frequency of the PWM power supply 220 is determined by the resistance of the ground circuit 230, but since the resistance value of the ground circuit 230 is changed, harmonics / harmonics do not occur.

This will be described in more detail as follows. When the AC power is applied to the circuit and is in a steady state, the amplitude of the voltage / current applied to each load is kept constant. In case of resonance, in which the phase of the imaginary part of the circuit impedance is 0, or in a frequency band that is not desired by the user. In the case of oscillation where an unidentified resonance occurs, the amplitude of the voltage / current increases more than the normal state, which causes excessive pressure inside the circuit. Therefore, heat or noise is generated in the circuit, and a problem occurs that the reception sensitivity is deteriorated in the communication device.

In general, impedance in an ideal RLC series circuit

Figure pat00005
If the imaginary part of impedance becomes 0, resonance or oscillation occurs. Resonance Frequency
Figure pat00006
. This is only an ideal series or parallel circuit, and since there is usually a resistor R1, which typically includes the leakage current of the capacitor, and the actual resistance R2 of the inductor itself, the general formula of the resonant (oscillation) frequency is
Figure pat00007
. Therefore, since the function of R is included, if the resistance value changes, no harmonic / harmonic components occur.

According to another embodiment of the present invention,

Figure pat00008
Figure pat00009
(For example, AM: 9 kHZ, FM: 100 kHz), the microcomputer 250 activates the transistor 232 of the ground circuit 230. Therefore, since the resistance value of the ground circuit 230 is changed, harmonics / harmonics do not occur.

According to another embodiment of the present invention, the harmonic filter unit 260 may be attached to the PWM power supply unit 220. In the receiving unit 210

Figure pat00010
When (f = oscillation frequency), the microcomputer 250 transmits a control signal to the harmonic filter unit 260. The T filter part 262 of the harmonic filter part 260 includes the balance reactor 264, and reduces the impedance of a specific order. The waveform correction resistor 266 reduces the impedance of the PWM power supply 220. The discharge resistor unit 268 is connected in series to the ends of the balance reactor of the T filter unit 262 and emits electric charges. Therefore, since the PWM power supply 220 generates a power source in which harmonic components are filtered by the harmonic filter unit 260, harmonics / harmonics do not occur.

5 is a flowchart of a PWM frequency self control method according to an embodiment of the present invention.

First, a system key is obtained (S510). In this case, the receiver 210 acquires information including image information or sound information.

Subsequently, the control output, the PWM oscillation frequency, and the PWM power supply unit are set (S520). In this case, the microcomputer 250 sets the initial state of the transistor 232 of the ground circuit 230 to OFF. The PWM oscillation frequency is adjusted through the setting of the PWM power supply 220.

Mute processing and stabilization time is obtained (S530). In the process of setting the control output, the PWM oscillation frequency, and the PWM power supply 220, whistle noise and bit noise due to unexpected harmonics / low harmonics may occur. Whistle noise occurs in a specific broadcast frequency band of the receiver and has a high frequency sound, and beat noise is a sound when two frequency phases coincide by overlapping two sounds with completely different frequencies. The amplitude increases. Therefore, when harmonics / harmonics are generated, the microcomputer 250 transmits a control signal to the harmonic filter unit 260, and the harmonic filter unit 260 filters the harmonic components in response to the received control signal to mute the signal. The PWM frequency self control device 200 obtains the time required for the system to stabilize.

The PWM oscillation frequency is counted and a range of two or more natural numbers n is set (S540). In this case, the microcomputer 250 transmits a control signal to the counting unit 240, and the counting unit 240 counts the PWM oscillation frequency generated by the PWM power supply unit 220 in response to the received control signal, and generates two or more natural numbers. Set the range of n.

The PWM oscillation frequency range is determined (S550).

Figure pat00011
If not (S560), harmonics / harmonics do not occur.

Therefore, the microcomputer 250 maintains the control output (S570). The transistor 232 of the ground circuit 230 is not activated, and the resistance 236 of the ground circuit is kept constant as one.

Figure pat00012
In the case of (S560), harmonics / harmonics are generated in the relationship between the reception frequency of the receiver 210 and the oscillation frequency of the PWM power supply 220. The counting unit 240 transmits a control signal to the microcomputer 250, and the microcomputer 250 receiving the signal activates the transistor 232 of the ground circuit 230. For example, before the transistor 232 is activated, only one resistor 236 exists in the ground circuit 230, but after activation, two resistors 234 and 236 are connected in parallel to the ground circuit 230. Therefore, the oscillation frequency of the PWM power supply 220 is determined by the resistance of the ground circuit 230. Since the resistance value of the ground circuit 230 is changed, harmonics / harmonics do not occur. Therefore, the control output, the PWM oscillation frequency, the PWM power supply unit is reset (S520).

According to another embodiment of the present invention,

Figure pat00013
Figure pat00014
(Eg AM: 9 kHZ, FM: 100 kHz), harmonics / harmonics do not occur. The flow of the flowchart
Figure pat00015
It is the same as the case, so it is omitted.

According to the present invention, when the reception frequency of the receiver in the counting unit 240 becomes an integer multiple of the oscillation frequency of the PWM frequency power supply, the transistor 232 of the ground circuit 230 is activated to change the oscillation frequency of the PWM frequency power supply. By using this, whistle noise and beat noise based on high frequency components are removed. As a result, the receiver system is stabilized and heat generation due to harmonic components is reduced, thereby reducing the error rate of the receiver system and improving the receiver sensitivity and signal to noise ratio (SNR).

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the scope of the present invention, but are intended to be illustrative, and the scope of the present invention is not limited by these embodiments. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents, which fall within the scope of the present invention as claimed.

Claims (7)

A receiver which receives a radio wave including image information or sound information;
A PWM power supply unit for generating / supplying power by the PWM oscillation frequency;
A ground circuit composed of a transistor and at least one resistor;
A counting unit for counting the oscillation frequency of the PWM power supply; And
f is the oscillation frequency of the PWM power supply, n is a natural number of 2 or more,
The receiving frequency of the receiver
Figure pat00016
If
Microcomputer to activate the transistor
PWM frequency self control device comprising a.
The method of claim 1,
A T filter unit including a balance reactor configured by connecting an inductor and a resistor in series to lower an impedance of a specific order;
A waveform correction resistor for reducing the impedance of the PWM power supply; And
A discharge resistor connected in series to an end of the balance reactor of the T filter part;
Harmonic filter unit characterized in that to remove the harmonic components from the PWM power supply unit
PWM frequency self-control device further comprising.
The method of claim 1,
The ground circuit connects the at least one resistor with the transistor to change the resistance of the PWM power supply;
PWM frequency self-control device characterized in that.
The method of claim 1, wherein when the frequency step of the receiver is x,
The receiving frequency of the receiver
Figure pat00017

If activating the transistor
PWM frequency self-control device, characterized in that.
Obtaining a system key;
PWM for generating / supplying power by the control output, PWM oscillation frequency, and PWM oscillation frequency to turn on / off the transistor to be activated when the receiving frequency of the receiver receiving the radio wave including image information or sound information satisfies a predetermined condition. Setting a power supply unit;
Counting the PWM oscillation frequency and setting a range of two or more natural numbers n;
Determining the PWM oscillation frequency range; And
Maintaining the control output;
PWM frequency self-control method comprising a.
6. The method of claim 5,
The determining of the PWM oscillation frequency range
When the frequency step of the receiver is x, f is the oscillation frequency of the PWM power supply, n is a natural number of 2 or more,
Receiving frequency
Figure pat00018

Set the control output if otherwise, and maintain the control output if
PWM frequency self-control method, characterized in that.
6. The method of claim 5,
Obtaining a mute process and a stabilization time through a time delay;
PWM frequency self-control method further comprising.
KR1020110124014A 2011-11-25 2011-11-25 Pwm frequency self control device and method for removing noise KR20130058155A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110124014A KR20130058155A (en) 2011-11-25 2011-11-25 Pwm frequency self control device and method for removing noise

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110124014A KR20130058155A (en) 2011-11-25 2011-11-25 Pwm frequency self control device and method for removing noise

Publications (1)

Publication Number Publication Date
KR20130058155A true KR20130058155A (en) 2013-06-04

Family

ID=48857470

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020110124014A KR20130058155A (en) 2011-11-25 2011-11-25 Pwm frequency self control device and method for removing noise

Country Status (1)

Country Link
KR (1) KR20130058155A (en)

Similar Documents

Publication Publication Date Title
EP2391036B1 (en) Spectrum spreaders including tunable filters and related devices and methods
WO2012092177A2 (en) Dynamic tuning for wireless charging system
US10044226B2 (en) Wireless power transmitter
EP3148045B1 (en) Constant current radio frequency generator for a wireless charging system
US20110103427A1 (en) System and method of controlling modulation frequency of spread-spectrum signal
WO2010089168A1 (en) Phase-locked loop
CN113491067A (en) Digital predistortion calibration
KR101994741B1 (en) A wireless power receiver and a control method for the same
US9419660B2 (en) Signal receiver with a duty-cycle controller
EP2747283A1 (en) Resonant circuit with automated trimming capabilities
KR20130058155A (en) Pwm frequency self control device and method for removing noise
US10211927B1 (en) Signal processing device and signal processing method
JP5017436B2 (en) Filter adjustment device, power supply control system, and filter adjustment method,
JP5996510B2 (en) System and method for reducing power consumption of an oscillator
JP4818364B2 (en) Receiver
US20240006918A1 (en) ASK Modulation & Demodulation System
KR20080004287A (en) Frequency oscillation circuit of tuner
JP2006217375A (en) On-vehicle electronic apparatus
JP2006229427A (en) Receiver
CN1985437A (en) Modulator comprising a dual-frequency oscillator and a synthesizer
KR100326185B1 (en) Control apparatus for generating multi frequency in vctcxo of dual mode wireless telephone set and method thereof
JP2010187293A (en) Demodulating device for power-line carrier communication
JP2006501742A (en) Circuit and method for reducing interference from switch mode circuits
JP2004140895A (en) Power unit
CN113078819A (en) Method for operating a switching device

Legal Events

Date Code Title Description
WITN Withdrawal due to no request for examination