An uninterruptible power supply comprises a power source and a housing to contain the power source. In accordance with one or more embodiments, an apparatus includes a charge pump that generates an output using a reference voltage, a low dropout regulator circuit, current-limit and a voltage-limit circuit. The flow of the liquid in proximity to the vibratable element causes the element to vibrate and mix the liquid and the additive. The joint body and the coupling member have a threading contact part. Sheet metal stock need be only half the thickness of conventional flat suspension bar stock with the same load-supporting capacity when incorporated in a hanging file folder thereby lowering manufacturing cost of suspension bars and hanging file folders.