Line Noise Attenuator Without Capacitor
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Solution Overview
Problem
Existing noise attenuators fail to effectively suppress common mode noise currents in power source lines due to series resonance phenomena and magnetic saturation, limiting their ability to reflect high-frequency noise back to the AC power source side without consuming excessive power.
Innovation Solution
A line noise attenuator that uses a resistance to power-consume high-frequency noise currents without a capacitor, setting the resistance value based on the inductor's reactance at high frequencies to ensure the noise is converted to heat, and maintaining a fixed ratio between inductance and resistance to prevent magnetic saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a capacitor and choke coil are used to suppress normal mode noise, then normal mode noise is eliminated, but series resonance phenomenon occurs causing harmonic currents to exceed limit values
Solution Approach 1:
The patent extracts the capacitor from the circuit configuration, using only the choke coil for noise suppression. This eliminates the series resonance problem caused by the capacitor-choke coil combination while maintaining normal mode noise elimination capability through the choke coil's inductance alone.
Solution Approach 2:
The patent changes the design approach by specifying inductance values for the choke coil that account for wiring modes and discontinuous points, rather than using a fixed capacitor-choke coil combination. This parameter optimization prevents resonance while effectively suppressing harmonic currents.
2Stability of the object's composition
If a resistance is connected in parallel to the choke coil to suppress series resonance, then resonance is reduced, but power consumption increases and noise current suppression is insufficient
Solution Approach 1:
The patent removes the parallel resistance component from the circuit, achieving resonance suppression through optimized choke coil inductance selection alone. This eliminates the power consumption issue associated with resistive damping while maintaining stability.
Solution Approach 2:
The patent optimizes the inductance parameter of the choke coil to naturally suppress series resonance without requiring additional resistive elements. The inductance is specifically selected based on wiring mode characteristics and noise frequency ranges.
3Stability of the object's composition
If the resistance value is limited to suppress series resonance, then resonance is controlled, but noise current power consumption is insufficient to eliminate noise obstructions
Solution Approach 1:
The patent removes the resistance component entirely, achieving both resonance control and adequate noise power consumption through the choke coil's inductive losses alone. The inductance is selected to provide sufficient damping without requiring resistive power dissipation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively eliminates noise currents in power source lines by power-consuming common mode noise without series resonance or magnetic saturation, purifying the electromagnetic environment and reducing re-radiated power.
Implementation Method 1
an inductor which tolerates current amount of a low frequency signal power; and a resistance to which the high frequency noise current blocked at the inductor can be flown
Implementation Method 2
a resistance value thereof is set, with respect to a reactance value of the inductor at an angular frequency of the high frequency noise current, to a prescribed value with which the high frequency noise current is changed to heat and consumed
Data Source
AI summary
To power-consume noise currents flown in power source lines, etc. in non-uniform wiring modes to such a level that noise obstructions can be suppressed by using a resistance without a capacitor that causes series resonance phenomena. It is a line noise attenuator for purifying electromagnetic environments by attenuating noise currents superimposed on a conductor line which supplies a signal power to a load from a signal power source. The conductor line operates as an antenna which receives high frequency noise currents. The conductor line has an inductor which tolerates flows of a low frequency signal power, and a resistance for changing the high frequency noise currents to heat and consuming the heat with a resistance value which is so set, with respect to a resistance value of the inductor replaced with a pure resistance value, that the high frequency noise current blocked at the inductor can be flown.