Abstract: A power converter that properly copes with the wiring defects on a feedback path is shown. According to a control signal, a power driver couples an input voltage to an energy storage element to provide an output voltage that is down-converted from the input voltage. The output voltage is further converted into a feedback voltage by a feedback circuit, and is entered to an error amplifier with a reference voltage for generation of an amplified error. A control signal generator generates the control signal of the power driver according to the amplified error. The power converter specifically has a comparator, which is enabled in a soft-start stage till the output voltage reaches a stable status. The comparator compares the amplified error with a critical value. When the amplified error exceeds the critical value, the input voltage is disconnected from the energy storage element.

Abstract: A power supply includes an isolated power converter and a DC/DC converter. The isolated power converter includes a primary winding connected to a primary power stage, a secondary winding to generate a first output voltage, and an auxiliary winding at the primary side to generate a voltage signal proportional to the first output voltage to stabilize the first output voltage. The DC/DC converter converts the first output voltage into a second output voltage for supplying for a load.

Abstract: An aspect of the present invention comprises a method of forming holes in a dielectric substrate comprising the steps of applying a layer of photoresist to a dielectric substrate, exposing portions of the photoresist to actinic radiation through a photomask to form a pattern in the photoresist for an array of holes to be etched in the substrate, developing the photoresist, etching the dielectric substrate to form an array of holes, each hole extending at least partially through the dielectric substrate, and removing the excess photoresist. Another aspect of the present invention is a method of simultaneously forming holes in a dielectric substrate some of which extend partially through the substrate and some of which extend completely through the substrate. Other aspects of the present invention are dielectric substrates formed using the methods of the invention.