Bedienungsanleitung Audison Thesis HV Venti (Seite 7 von 25) (Englisch)

474147

Zoom out

Zoom in

Vorherige Seite

1/25

Nächste Seite

value on every output device is possible, keeping stable the total current absorbed by the ampliﬁ er when in idling status.

All this results in the increase of the output stage to class A value.

This value is the typical car audio ampliﬁ ers’ weak point. Due to installation needs, they always require several output

devices in parallel in order to work on very low loads and in the meantime to have low consumption since the car battery

supplies them.

This conﬁ guration proved to be especially valid both in terms of power performance and of acoustic quality: the DMOS

power transistors used as driver supplies the current that the BJT output needs because their “current gain” decreases

when current increases. Thanks to the DMOS voltage ampliﬁ ers’ speciﬁ c feature, the conﬁ guration used insures that this

gain decrease doesn’t overload in current the previous voltage ampliﬁ er stage and it can have a constant distorsion for

every output load.

Also regarding the output power stage, an innovative solution was adopted.

In any ampliﬁ er high supply currents, power output and return ground current create electro-magnetic ﬁ elds interfering

with our precious audio signal.

In order to avoid this kind of situation, you are often forced to use convoluted wiring which compel designers to accept

compromises. Compromise is not accepted in the HV venti.

Inside the HV venti a six layer thick copper board was used which gathers all the output stage return currents; the layout

was created so that each current path comes to close contact with the return current ﬂ owing backwards.

This way the electro-magnetic ﬁ elds are out of phase and nullify each other: this solution could be deﬁ ned as a “balanced

power supply”.

e) Power supplies

There are two Hi power supplies for each channel. They supply power exclusively to the output stage.

Each power supply pair of each channel works in Synchro- PMW mode: an independent circuit controls each of them.

However, they are synchronized with one another and are designed to supply one single power source, one supplies the

positive and the other the negative power.

This solution, which has been employed by Audison for a very long time, allows engineers to increase the impulsive

current transient response necessary to the ampliﬁ er.

In HV venti this conﬁ guration was doubled in each of the two channels: the ampliﬁ er is actually set into a Dual Mono

conﬁ guration, reducing interference between the channels.

Furthermore, the two pairs of power supplies were synchronized to reduce radio frequency electro-magnetic

interference.

The use of 4 separate power supplies has a further advantage.

Power split allowed the use of just one MOSFET, although a large power one, for each rail of each power supply, thus

avoiding the paralleled conﬁ guration that is perhaps the main cause of ampliﬁ ers failures.

Each transformer and relative ﬁ lter inductor were enclosed in non-magnetic metallic shells and then ﬁ lled with resin.

This procedure further increases reliability for two reasons: ﬁ rst of all, coils are blocked and therefore made immune to

vibrations; secondly, heat is homogeneously distributed, thus preventing any possible overheated areas.

The resin-ﬁ lled groups were then mounted onto the aluminium thick bottom plate to allow heat to be dissipated through

side heatsinks.

In the Dual Power function, each transformer was equipped with two secondary windings that are selectable by positioning

minifuses into the two available jumpers. For Hi Current conﬁ guration you need 15A fuses, while for Hi Power conﬁ guration

you need 10A fuses; the fuses are factory provided.

All the necessary adjustments for Dual Power conﬁ guration are automatically managed by the ASC (Ampliﬁ er Status

Controller) .

All the rest of the power needed for signal circuits are supplied by two Flayback power supplies, one for each channel.

They have reduced power but are high efﬁ ciency types and are synchronized with the main power supplies. The whole

power supply group is connected to the car battery through two supply terminals equipped with a strip fuse. Two further

terminals are provided to connect an external capacitor.

f) ASC: Ampliﬁ er Status Controller

The ASC unit (Ampliﬁ er Status Controller) is in charge of managing all of the ampliﬁ er’s conﬁ guration functions.

It is equipped with its own proprietary microprocessor. Using the Status Display, you can visualize operational functions

or any possible anomalies of the ampliﬁ er or of the external systems. The ASC also handles the protection circuits and

checks thermal conditions of each component and maximizes the fans to keep things under control. Vumeters are used

to identify output power.

- 6 -

DESCRIPTION

INTRODUCTION

Missbrauch melden von Frage und/oder Antwort

Libble nimmt den Missbrauch seiner Dienste sehr ernst. Wir setzen uns dafür ein, derartige Missbrauchsfälle gemäß den Gesetzen Ihres Heimatlandes zu behandeln. Wenn Sie eine Meldung übermitteln, überprüfen wir Ihre Informationen und ergreifen entsprechende Maßnahmen. Wir melden uns nur dann wieder bei Ihnen, wenn wir weitere Einzelheiten wissen müssen oder weitere Informationen für Sie haben.

Audison Thesis HV Venti Seite 7

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info