Audi 80/Avant (B4)

since 1991-1995 of release

Repair and car operation

Bosch firm generator (the old version), rear view

As Audi 80 cannot pull along a lengthening cable, production of an electricity should occur directly in the car. This task is carried out by the generator. And and not only for lighting as it was once, but also for all electric systems in Audi.

Three-phase generator of an alternating current

Capacity

Approximately till December, 1991 some Audi 80 versions were equipped with the 65-amperny generator, only 90-amperny generators now are established. In special options can stand and 110-amperny or 120-amperny generators. To calculate generator capacity, it is necessary to increase the specified maximum current by rated voltage in 14 V.Poluchayetsya, for example 90 And x 14 In = 1260 W. You already noticed: the generator in a 12-voltny onboard network actually gives 14 V.Potomu chto to the storage battery the current for a charge only thanks to this small difference in tension can arrive.

Transfer from a pulley of a cranked shaft to a pulley of the generator is chosen, by the way, so that already on single turns about 2/3 capacities of the generator were made.

Service of the generator and safety measures

The three-phase generator of an alternating current differs in rather high capacity and develops a current even on single turns of the engine. Its sliding graphite contacts (brushes) maintain more than 80 000 km. According to the name it makes an alternating current which in the car is not used as the accumulator can be charged by only a direct current. Therefore the vypryamitelny diodes turning an alternating current into a pulsing direct current are built in the generator. As these diodes are sensitive to a high voltage, you should remember the following:

• At the working generator it is impossible neither to weaken, nor to connect wires between the storage battery and the generator. Because of it there can be a power surge (tension peaks) that will lead to diode damage.
• The three-phase generator of an alternating current should not work in the absence of correctly connected, serviceable storage battery because the accumulator serves as some kind of buffer from retension.
• All cable connections between the three-phase generator of an alternating current, the storage battery and metal of a body or the power unit ("weight", the case) should sit strong. To dangerous peaks of tension can lead even leaky contact.
• At a fast charge of the accumulator (not to apply at a charging by means of devices to a charge with automatic shutdown) and at electric welded works on a body both wires that diodes of the generator were not damaged should be disconnected from the accumulator.