Electrical and Electronics

This military group fuel be used to build an electric power writer, much(prenominal) as the iodine described in this idea. A coil prone to a shaft spins within the magnetic field ofa U make magnet. 3 conveniently designed semiconductive disks allow the electrical commove of the generator to be fed either with alternating watercourse or direct current. the draw in terms is sinusoidal with zero mean value (Fig. 2). Its absolute frequency is equal to the number of revolutions per second exe visited by the loop. Each terminal of the loop is committed to a metallic wicket. The contacts with sound atomic number 18 make by means of fixed brushes.If the brushes are onnected to an electrical commitment, an alternating current will be naturalized in the locomote. Keywords. Alternating Current, Direct Current, Generator, magnetised Field, Induced Voltage. 1. Introduction Although diverse forms of energy ( mechanistic, thermal, chemical etc. ) can be converted into electri cal energy, the expression electric generator is reserved, in the industry, energy into electrical energy. The generators that state direct current (DC) are called dynamos and the ones that produce alternating current (AC) are called alternators.The construction described in this paper is a generator capable of supplying an electrical load ith the desire persona of current alternating current or direct current. s AC output go through 1. AC generator. 2. AC generator teaching of operation. Figure 1 illustrates the principle of operation of an AC generator. A fit loop rotates within the magnetic field generated by a magnet, which induces an AC potency between the loop terminals. The periodic change of the potential augury is due to the change of the position of the coil relatively to the magnetic poles.The premium of the potentiality depends on the magnetic field strength and is also right away proportional to the rotating speed 1, 2, 3, 4. If he magnetic field is uniform and the rotation speed is constant, the voltage induced between Figure 2. AC generator output. 3. DC generator principle of operation. The described AC generator whitethorn be transformed into a DC generator, substituting the contact rings by a mechanical switch. As illustrated on Fig. 3, a mere(a) switch may be done with a metal ring divided into two isolated halves (segments), which are mounted in the axis.This type of commutator is denominated collector. segment of the collector. When the loop rotates, an AC voltage is induced in the coil, only as in the AC generator. But, before reaching the oad, the induced voltage is transformed into a DC voltage by the collector (Fig. 4), which plant as a mechanical rectifier. The contact segments of the collector move to a different brush each half turn of the loop, keeping a unidirectional current flowing through the electrical load of the circuit 1. The rotation speed has to be well determined so that the concluding result is the expe cted one.As stated before, the rotation speed influences the induced voltage amplitude and frequency. U shaped strong permanent magnet, shown in Fig. 6. The virtually challenging part to build was a contact rings and collector unit (Fig. 7). It was ade of three printed circuit board disks, concentrically mounted on the rotating axis. The two smaller disks were kept with their entire conductive layer and were think to supply the generated AC voltage. The conductive layer of the larger disk was cut into two halves, in order to implement the collector, which mechanically rectifies the generated AC voltage.Figure 5. bankroll with atomic number 26 bone marrow. DC output Figure 3. DC generator. Figure 6. indissoluble magnet used to induce a voltage in the coil. Figure 4. DC generator output. 4. Generator description Instead of a simple loop, an iron core coil with 1241 turns of O,16mm2 varnished copper ire was used. The iron core and its windings are shown in Fig. 5. The magnetic f ield used to induce a voltage between the coil terminals was provided by a Figure 7. Three coaxial printed circuit board disks with coil on top. 45 Fig. 8 and Fig. 9 illustrate how the rings and collector unit was built in a more comprehensive way.In Fig. 8, a cross-section of this unit is shown, reveal how electrical connections were made one terminal of the coil was connected to one of the smaller disks and to one of the halves of the larger disk (collector) the other terminal was connected to the other smaller disk and to the ther half of the larger one. Fig. 9 shows a panoramic view of the assembly and the generator outputs responsible electrical load. In order to make the generator operate properly, the DC output brushes positions essential(prenominal) be displaced by 1800 from each other.The AC output brushes may be placed anywhere on the respective disks. coil Copper outfit Insulator Copper Solder Figure 8. Connecting the coil to the three coaxial printed circuit board di sks. power could be easily measured, some affiliate of mechanical power meter was needed and it was not available. There are always mechanical and electrical power losses in the serve of ransforming mechanical energy into electric energy. Mechanical losses may be reduced by lubricating friction points. The generator was put to rotate at 3000RPM the measured induced voltage was 1,2V peak-topeak, with a 50Hz frequency. . Conclusions Spinning a telegram loop within a uniform magnetic field in a convenient fashion induces a voltage between the loop terminals. Rotation speed influences the induced voltage amplitude and frequency. If an electrical load is connected to the loop terminals, a current will be established in the circuit. The current generated by a basic electrical generator is alternating current. If the generator s intended to supply direct current, it must have a device working as a mechanical rectifier the collector.A device capable of generating two AC voltage and DC vo ltage has been presented. A coil attached to a shaft spins within the magnetic field ofa U shaped magnet. Three conveniently designed conductive disks allow either with alternating current or direct current. This device is very useful to illustrate the principles of electrical energy generation. It also shows the main(prenominal) similarities and differences between AC and DC generators the working principle is the same for both machines, but the AC generator has contact rings and the DC enerator has a collector.