A primary side controlled power converter having a voltage sensing means
coupled to a transformer of the power converter and configured to provide
a voltage feedback waveform representative of an output of the
transformer is provided. A primary switching circuit operates to control
energy storage of a primary side of the transformer. The primary
switching circuit is operable during an on time and inoperable during an
off time. The on and off time is switched at a system frequency. A
feedback amplifier generates an error signal indicative of a difference
between the voltage feedback waveform and a reference voltage. A sample
and hold circuit samples the error signal at a periodic frequency during
the off time. An error signal amplifier is configured to provide the
sampled value to the primary switching circuit wherein the primary
switching circuit controls the transformer and thereby regulates an
output of the power converter.