Abstract: A vehicle system includes a voltage sensing circuit configured to detect voltages across cells in a fuel cell stack, and powered by a power supply sharing a voltage reference with the cells and having a voltage magnitude greater than a sum of voltage magnitudes of the cells. The system further includes a controller configured to, responsive to a change in polarity in at least one of the voltages indicative of freezing of the cells, issue an alert notification.

Abstract: A solar photovoltaic module safety shutdown system includes a module-on switch coupled with a first circuit having a photovoltaic module and a System-Monitor device. The System-Monitor device couples to the module-on switch through a second circuit and to the photovoltaic module and an AC main panelboard through the first circuit. A module-off switch operatively couples with the photovoltaic module and the module-on switch. The System-Monitor device supplies a System-on signal to the module-on switch through the second circuit. The module-on switch disables the photovoltaic module by shorting it or disconnecting it from the first circuit in response to the System-On signal not being received by the module-on switch from the System-Monitor device. The module-off switch disables the photovoltaic module by shorting it in response to the System-On signal not being received by the module-on switch when the photovoltaic module is irradiated with light.

Abstract: A method of fabricating a MEMS switch having a free moving inductive element within in micro-cavity guided by at least one inductive coil. The switch consists of an upper inductive coil at one end of a micro-cavity; optionally, a lower inductive coil; and a free-moving inductive element preferably made of magnetic material. The coils are provided with an inner permalloy core. Switching is achieved by passing a current through the upper coil, inducing a magnetic field unto the inductive element. The magnetic field attracts the free-moving inductive element upwards, shorting two open conductive wires, closing the switch. When the current flow stops or is reversed, the free-moving magnetic element drops back by gravity to the bottom of the micro-cavity and the conductive wires open. When the chip is not mounted with the correct orientation, the lower coil pulls the free-moving inductive element back at its original position.

Abstract: The present invention relates to an electrical relay in which a solid slug is moved within a channel and used to make or break an electrical connection. The solid slug is moved by electromagnets. In the preferred embodiment, the slug is wetted by a conducting liquid, such as liquid metal, that also adheres to wettable contact pads within the channel to provide a latching mechanism. The relay is amenable to manufacture by micro-machiningtechniques.

Abstract: An electrical relay using conducting liquid in the switching mechanism. Two electrical contacts are held a small distance apart. The facing surfaces of the contacts each support a droplet of a conducting liquid, such as a liquid metal. A piezoelectric actuator is energized to reduce the gap between the electrical contacts, causing the two liquid metal droplets to coalesce and form an electrical circuit. The piezoelectric actuator is then de-energized and the electrical contacts return to their starting positions. The liquid metal droplets remain coalesced because of surface tension. The electrical circuit is broken by energizing a piezoelectric actuator to increase the gap between the electrical contacts and break the surface tension bond between the liquid metal droplets. The droplets remain separated when the piezoelectric actuator is de-energized because there is insufficient liquid metal to bridge the gap between the contacts. The relay is amenable to manufacture by micro-machining techniques.

Abstract: A bypass apparatus and method for series connected energy storage devices. Each of the energy storage devices coupled to a common series connection has an associated bypass unit connected thereto in parallel. A current bypass unit includes a sensor which is coupled in parallel with an associated energy storage device or cell and senses an energy parameter indicative of an energy state of the cell, such as cell voltage. A bypass switch is coupled in parallel with the energy storage cell and operable between a non-activated state and an activated state. The bypass switch, when in the non-activated state, is substantially non-conductive with respect to current passing through the energy storage cell and, when in the activated state, provides a bypass current path for passing current to the series connection so as to bypass the associated cell. A controller controls activation of the bypass switch in response to the voltage of the cell deviating from a pre-established voltage setpoint.

Abstract: A multi-positional mercury switch (1) for use with miniature relays (3). The mercury switch apparatus has magnetic contact structures (11, 13, 16, 17) supported in a sealed envelope member (10) with free ends thereof located in the envelope member and positioned to engage or disengage each other in response to a magnetic field generated by current appearing in a coil (310) externally surrounding the envelope member. A magnetic contact structure (11) has a mercury wetted surface (113) and an opening (111) at a free end (116) extending from the mercury wetted surface through the magnetic contact structure for forming a mercury contact (117) opposite the mercury wetted surface.

Abstract: A resettable switch is disclosed having a conductor maintained in contact with a reservoir of mercury to conduct current therethrough during normal operation. During impact or roll over, the mercury is spilled from the reservoir and prevented from returning thereto by cone-shaped retainers maintained in a telescoped relation by a spring, thereby opening the switch. The switch may be reset by depressing a plunger which aligns slots in the telescoped retainers, which permits mercury to return to the reservoir.