16
Power Provision Indications
KW 4V8
In order to prevent variations in voltage and ground loops, the same cable diameter
must
be used for the negative
conductor (-) as for the positive conductor (+). Because of the potential for variation, the auto body is
not
appropriate
as the negative pole in this application.
In order to prevent distortion, all audio devices must be attached to a
central ground
. This can be determined
during installation in accordance with the type of vehicle. A direct connection at the negative terminal of the
battery is not always advantageous because of the possibility of technical failure. For this reason, select the engine
block or search for a minimal disturbance on the autobody and from this point supply
all devices
with the negative
conductor (–) (use multiplier).
The same criteria apply for the positive terminal (+). The battery lines must be placed on a multiplier to avoid
distortion loops. All audio devices (including radio and CD player) as well as memory lines are supplied with
current from this point.
If, for reasons of interference suppression, the positive (+) current supply must be filtered, then only one filter
choke with appropriate total maximum capacity should be placed into the (+) main line (consider total value of
current of all devices). Additional filters in individual device plus supplies worsen the screening effect.
With high rendition volumes, especially in the bass range, the amplifier can distort when long cable lengths cause a
premature voltage drop. This can be prevented by using a cable with a large diameter and minimizing the transition
resistance at the connection points. Appropriate precautions can be taken by using low-loss battery clamps and a
multiplier during the first installation.
With insufficient cable diameter or large requirements of electrical current within the impulse range of the bass
rendition or by active operation of more than one amplifier, an additional buffer condenser can help to improve the
clippings. This supplies sufficient current in the millisecond range through high capacity (~1F/20V) and allows for
additional screening and levelling of current supply. The assembly is performed directly at the amplifier or
multiplier.
Determining the „Central Ground“
n
Completely install and check system.
o
Provisionally make the minus (–) connection of the audio system on the auto body minus (Point 1).
If the potential equalization line is not available, shift from the generator housing to Point 1.
p
Power on system, insert an empty cassette or CD (0dB-track) and set volume to the minimum level.
q
Start the engine and place all electricity consuming devices into operation, including lights, windshield
defrosters, and blowers.
ª
If the revving of the engine creates whistling distortion that becomes more or less frequent during
revving, the ground connection must be corrected.
r
Remove antenna plugs from car radio. If the distortion disappears there is a potential distortion
at
„
antenna
ground to battery”.
ª
Remedy: Insert galvanic isolated separation filters into the antenna cable. (Art. No. 251001/251055).
