Conventional switching can be used to drive a brush dc geared servomotor, in terms of adjusting the position to our liking. For brush geared dc servomotor drivers we use a switching bridge where each arm is used a power transistor, in the process of switching bridge need to be considered the area where the short circuit is likely to occur, to avoid it we use dead time, as well as the possibility of a short circuit due to the upper arm and the lower arm of the bridge turns on at the same time for that it is necessary to make a transistor-transistor logic circuit so that the upper arm will not turn on when the lower arm is on or vice versa. From the results of conventional switching, it is able to drive the DC brush geared servomotor to the desired position.

Liner equations with n variables can be solved if there are n equations, the matrix is formed n x n square matrix, using the inverse matrix method. In this research, the linear equation used comes from the rod and mesh grounding system method, which is solved by the finite element method to calculate the grounding impedance, from the results of other research researchers. Here the researcher wants to inform in this study how to solve the linear equation with a calculation program. And the research results are plotted in Cartesian coordinates V = V (t). The results of this calculation program can be used to estimate how much the transient voltage is in the ground rod / mesh in the place where the electrical power system substation will be built when lightning strike with an amplitude of 34 kA/switching with a current of 34 kA/step with a current of 34 kA crash it. To adjust the transient voltage by adjusting the length of the finite element, required in accordance with the applicable safety level, while the subsequent arrangement can by increasing the number of mesh or increasing the length of the mesh.

This paper presents a dc-dc ZETA converter with reduced switching loses at the main switch. Reducing switching loses is obtained by application of a resonance switch, where turn-on by the zero voltage and rising voltage at turn-off is limited by capacitor that it's placed parallel with main switch. The operational principle of the proposed dc-dc ZETA converter with reduced switching loses has been analyzed under different modes of switching operation. To validate the proposed converter, the implementation is carried out using PSIM software. Simulation result shows that the main switch turn-on at the zero voltage and turn-off at the main switch voltage increase in a quadratic function, so that the result of the voltage and current multiplying is lower, on the other hand the loses of the main switch can be reduced.

No abstract

3 phase inverter is needed, besides to change the dc to ac voltage as needed, in the industry every CNC or NC machine needs an inverter to regulate the rotation speed of the motor, constant motor rotation requires for cutting in certain a variety of speeds feeding processes, wherein conventional machines gear is used to change the rotation speed of the motor, here the AC voltage is changed to DC and returned to AC according to the required frequency. For this reason, the researchers tried to research switching the 3 phase inverter algorithm with the principle of space vector pulse wide modulation. Here the switching theory follows the SVPWM switching rule, where the resultant vector is the result of each sector of each phase. The microcontroller accepts the input data, that will be used to generate frequency, the required PWM calculation, the sector, estimates the switching process per sector, the switching sector according to the algorithm results rule. These results will generate inter-phase voltage greater than conventional switching methods, reducing noise, switching steps shorter only 6 steps, improve the power factor. The switching algorithm is ready to be used to make 3 phase inverters.