Voltage-converting circuit for the power supply of an electrical consumer of high output, particularly a bobbin winding machine

An electrical circuit for the conversion of a multiplicity of commercial power voltages into a supply voltage for use with a device with high electrical power requirements, such as a textile bobbin winding machine, said supply voltage being independent of the respective commercial power voltage, said electrical circuit comprising:

• a rectifier assembly for generating a primary intermediate circuit DC voltage in a range of approximately 300 V to approximately 1000 V by rectifying and filtering the commercial power voltage having a range of values between approximately 180 V and approximately 600 V;
• a converter assembly having a plurality of triggerable power switches for converting said primary intermediate circuit DC voltage into an AC voltage having a rectangular waveform;
• a high-power transformer having an intermediate circuit connected thereto for transforming said AC voltage having a rectangular waveform into said supply voltage;
• and
• a control assembly for switching said power switches at zero voltage responsive to the primary intermediate circuit DC voltage, the current in the primary winding of said high-power transformer, and the voltage and the current in the secondary intermediate circuit, said control assembly switching said power switches using a variable pulse width of the AC voltage having a rectangular waveform required for achieving a predetermined supply voltage.