Common mode noise cancellation circuit

摘要

A common mode noise cancellation circuit eliminates common mode noise generated by one or more high-frequency switching devices. A common mode noise waveform generated by the one or ore switching devices is capacitively coupled from the primary winding to the first secondary winding of a transformer. A set of cancellation secondary windings generates a common mode cancellation waveform, and cancels the common mode noise waveform because the common mode cancellation waveform is approximately equal in amplitude and opposite in phase to the common mode noise waveform. A triac control circuit receives an AC input and determines whether the AC input is within a range where multiplying of the DC voltage is implemented. If the triac control circuit determines the AC input is within the range, the triac control circuit transmits a triac firing signal to the triac circuit. The triac circuit charges a capacitor bank to multiply the DC voltage.