Abstract: This invention relates to the control of the temperature of heated fluid flow through a so-called single pass electrical heater. Specifically, a controller and accompanying flow circuit including a flow through single pass electrical heater is disclosed which provides for heating of water upon initiation of flow. A two stage control protocol is utilized for routing current under precise control to the heater element. In the first protocol utilized at start up to a control temperature limit slightly below the temperature set point, phase angle of current turn on with zero crossing current turn off control a 220 volt current to the single pass heater element. Once the control temperature is achieved, incremental adjustment of phase angle thereafter occurs with rapid asymptotical approach of the output temperature of the flowing water to a preselected temperature "set point" occurs.

Abstract: A patient lift apparatus is provided with a U-shaped base that folds to enable convenient reduced width storage of the unit when not in use. Accordingly, the U-shaped base of the unit has a hinge with a vertical axis in each leg of the "U". These hinges are located midway of each of the vertical legs. Typically, these hinges provide for a pivotal movement of the casters at the ends of each leg of the "U" from a caster extended position for patient lifting and transport to a caster folded position parallel to and spaced apart from the base of the "U". A releasable lock mechanism is provided to each leg for locking the hinge in either the caster extended position or the caster folded position. The lock includes an outer moving sleeve with a spring biased inner key connected to the spring biased sleeve. The key moves with the sleeve and fits into and out of paired apertures in the hinge.