Stand the test generator is fairly expensive equipment, not available to every car owner, so some motorists prefer to do them with my hands. So device for the promotion of the generator can be built out of the motor with the clutch decommissioned industrial sewing machines that were previously produced at the Podolsk or Orsha mechanical plants.
It is preferable to use motors more power – 1 kW, 2800 Rev/min. With such a home-made stand you can measure the following parameters: operating voltage generator, the number of revolutions and the load current. In principle, it is possible to use other types of electric motors with pulleys under the belt corresponding to the generator. It remains to sum up to the generator to 12V, connect according to the diagram. Do not forget the external relay (if any), and weight.
Then start the engine and measure the voltage at the output of the generator. Check the alternator on the bench gives the opportunity to determine the status of the generator and its main characteristics nominal. It is necessary to observe a very important requirement is that the alternator brushes have to be carefully lapped to the contact collector rings, the rings must be clean. So, install the generator on the stand, turn the motor on stand, set with the help of rheostat output voltage of approximately 14V, and the frequency of rotation of the rotor – up to 5 thousand rpm.
After two minutes of operation in this mode, measure the amperage provided by the generator. A working generator will show at least 44 A. If the output readings will be significantly less, it could indicate problems in the windings of the rotor and the stator, damage to the valves, the wear of the slip rings and brushes. If you have any suspicions about the malfunction of the valves of the rectifier Assembly of the alternator, then check the amperage returns to preheat the generator.