REVERSIBLE CONVERTER FOR ELECTROLYTIC CHROMIUM PLATING Russian patent published in 2015 - IPC H02M7/17 

FIELD: electricity.

SUBSTANCE: in a reversible thyristor converter its power circuit comprises two multiphase groups of thyristors connected in parallel opposition and an in-series smoothing reactor, and a control circuit of the converter comprises an in-series connected automatic control system, a multichannel pulse-phase control system for the thyristors and two multichannel groups of output keys, which outputs are connected to control electrodes of the respective thyristors in the power circuit; the control circuit also comprises a reversible unit, which two outputs are connected to joint inputs of different groups of output keys; in the power circuit there are an additional smoothing capacitor and a monitoring key, which first outputs are interconnected in-series and the second outputs are connected to output leads of the converter. The key control input is connected to one output of the reversible unit outputs. At that the capacitor introduced additionally to the power circuit is made as parallel electrolytic capacitors while the monitoring key introduced additionally to the power circuit is made as parallel MOSFET transistors. The use of the monitoring key as the parallel MOSFET transistors with a channel of an n-type allows almost complete eliminating the impact of the key to rippling of current with the cathode polarity and the use of parallel high-capacity electrolytic capacitors in smoothing LC-filter allows reducing significantly rippling of current with the cathode (direct) polarity, at which the deposition of chromium plating takes place, thus allowing the perfection of mechanical and physical properties of this plating and reducing the weight and dimensions of the smoothing filter.

EFFECT: reducing the ripple ratio for the output current of the reversible thyristor converter up to minimum values allowing the improved quality of chromium plating and other types of plating.

3 cl, 1 dwg