Rainbow 271052 Installation Manual - page 35
16
Power Provision Indications
iPaul DM2000
In order to prevent voltage differences and ground loops, the same cable diameter must be used for the negative
conductor (-) as for the positive conductor (+). Because of the potential large differences, 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 for technical failure reasons. For this reason, select the engine block or search
for a minimal disturbance on the auto body 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 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 the individual equipment plus supply worsen the screening effect.
With high rendition volumes, especially in the bass tone range, the amplifier can distort due to long cable lengths
causing 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 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/40V) and allows for
additional screening and leveling of current supply. The assembly is performed directly at the amplifier or
multiplier.
Determining the „Central Ground“
Completely install and check system.
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.
Power on system, insert an empty cassette or CD (0dB-track) and set volume to the minimum level.
Start the engine and put all power users into operation, including light, windshield defrosters, and blowers.
If the revving of the engine creates whistling distortion that becomes more or less frequent during
revving, the ground connection must be corrected.
Pull antenna plugs out of car radio. If the distortion disappears there is a potential distortion „antenna ground
to battery.“
Remedy: Insert galvanic isolated separation filters into the antenna cable. (Part-No. 251001 / 251055).