DC – AC Medium Frequency Converter

Votes: 2
Views: 2120

This idea solves the problem of hardening steel surfaces. It is applied to flat surfaces or cylindrical surfaces ready to be hardened by thermal methods. These areas are found in the automotive industry, aerospace, rolling stock sub-assemblies and other sectors that require hardening on thin surfaces. The novelty of my system is that on the market there are products manufactured with electronic components which are not feasible at high power. The idea I present has the advantage that it can be of large or even infinite power. Given that this idea is implemented, it can be purchased by customers interested in high power hardening or with ideas for this technology to be applied in other sectors.

 Figure 1 presents a commutator of a Brushed DC Electric Motor with 6 copper contact bars powered by continuous DC current. Analyzing the schematic, it is noted that each copper bar (or segment) is connected to a segment which skips the neighboring segment. There are two networks that connect the two slip rings. It is noted that by the movement from one segment to other, direction of electrical current flow from the two slip rings changes and its frequency depends on the f = k / 2*n relationship, where k is the number of segments, and n is the rotating speed in revolutions per second. Increasing the frequency can be done by increasing the number of segments or by increasing the rotating speed of the motor which drives the system. In Figure 2 it can be noted that flat or cylindrical surfaces can be hardened. If placing the segments on a circle does not provide conditions technologically, one proceeds to Figure 3 in which by extension providing the higher speed of rotation and higher number of segments any frequency. This product will be obtained by the help of manufacturing technology of the DC motors commutators, and the slip rings after the manufacturing technology of wound rotor asynchronous motors.

Components are very cheap compared to static converters on the market. Adding that many of the components can be salvaged, it is obvious that the cost of production decreases.


Voting is closed!


  • Name:
    Marian Bida
  • Type of entry:
  • Profession:
  • Patent status: