Har brukt Consonance filteret på preamp en liten stund,
ingen negativ virkning,positiv virkning liten + .
Siden de ikke er noe støy av betydning på nettet fortiden som kan forsterkes
er nok det årsaken til at den vanlige negative virkningen filteret har gitt ikke er tilstede.
Uteblivelse av den store positive virkning av Consonance filteret på preamp
er vel også normalt,men hele årsaken vites ikke,enda.
Så inspirert av filteret til "JK",på forsøkstadiet..
Får spørre fruen fint om det passer å prøve det nå
"lettfattelig" og god om EMC filtre
https://en.tdk.eu/download/528632/64440358c2e92def9ca9d86aeb3f0c85/pdf-general.pdf
Propagation modes
(a) = Asymmetrical or common-mode interference:
interference between all lines of a cable and reference potential.
It occurs principally at high frequencies (from about 1 MHz).
(b) = Symmetrical or differential-mode interference:
interference between two lines (L-L, L-N).
It occurs principally at low frequencies (up to some 100 kHz).
(c) = Unsymmetrical or normal-mode interference:
Interference between a single line and reference potential
Selection criteria for EMC filters
To comply with the currently applicable regulations, a frequency range of 150 kHz to 1000 MHz,
in some cases also up to several GHz, has to be taken into consideration, in most cases, in order
to ensure electromagnetic compatibility; in addition, however, further aspects such as lowfrequency
system perturbations should be considered.
EMC filters must thus have good RF characteristics and are usually required to be effective over
an extremely broad frequency range.
For individual components (inductors, capacitors), the RF characteristics are specified by stating
the impedance as a function of frequency.
The insertion loss is used as a criterion for selecting EMC filters (see Section 3.1.17).
If the device under test (DUT) is terminated on both sides with a resistive impedance of 50 Ω, for
example, the result of the measurement is referred to as being the 50-Ω insertion loss. Priorities
for considering the three possible kinds of insertion loss, namely
asymmetrical (common mode),
symmetrical (differential mode) and
unsymmetrical
must be decided upon depending on the desired application.
The measuring method for 50-Ω insertion loss has been adapted from the field of communications
engineering and is also specified in the relevant national and international standards.
Although it permits a comparison of different filters, it provides only little information on the efficiency
of the filter in practical applications.
The reason is – as already mentioned in the previous section – that neither the interference
source, the disturbed equipment nor the connected power line system will have a resistive impedance
of 50 Ω at frequencies below 1 MHz.
Likewise, the attenuation of interference pulses cannot simply be determined on the basis of the
insertion loss curve. In this case, it is also necessary to take the non-linear response of the EMC
chokes in the filters into consideration.
Filter-specific values may be quoted upon request if you send us the pulse shapes in question.
