Abstract: An improved electric actuator is provided, having in association therewith a resolver. The actuator includes a stationary and a rotatable housing, and an electric motor within it. The electric motor drives the rotary housing through a speed reducing harmonic drive mechanism. The actuator has an opening in the rotary housing, and a cavity inwardly of the opening having a mating anchoring element connected with the stationary housing. A modular resolver is provided, of a shape and size to have a major portion of it occupy the cavity provided in the actuator, and having a mating part for engaging the mating part of the stationary housing, upon assemblage of the resolver to the actuator. A rotatable part of the resolver is secured to the rotary housing. A heat dissipation system is provided, including a fan mounted on a rotary member of the actuator and a closed circuit for the passage of air between the fan and a heat conductive plate forming a part of the stationary housing.

Abstract: Apparatus for use with existing electrolyte passage means for replenishing electrolyte within the fuel cell stacks of a fuel cell stack module to keep the matrices in the optimum electrolyte-wetted condition. Pump means is provided to withdraw a predetermined volume of electrolyte from electrolyte reservoir means and propel it in a series of pulses of predetermined duration through transfer means to distribution means which divides the electrolyte volume into streams according to the number of fuel cell stacks in the module. Each portion of the electrolyte volume is then introduced into existing electrolyte passage means. The pulses of electrolyte must be of a sufficiently short duration that no electrolyte streams are still issuing within distribution means when electrolyte has reached electrolyte passage means of the fuel cell stacks. If the streams are still issuing at this time, a circuit will be completed between the fuel cell stacks through the electrically conductive electrolyte, damaging the stacks.