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Switch- mode power supplies convert the AC line directly to high voltage DC, then the precision PWM (pulse width modulation) inverter creates a new AC power signal at a frequency more than 1000 times higher than the original wall frequency of 50/60Hz. This new high voltage, high frequency power signal is then fed into a custom high frequency transformer that steps the voltage down. A high frequency rectifier and high ESR filter capacitors finish the process off by converting the high frequency A