A device to allow a two-way switch to be used in an electrical circuit comprising multiple switches. Using the invention device, the two-way switch can operate as either a three-way switch or a four-way switch in a multiple-switch electrical circuit using AC mains voltage.

In some aspects, a switching device for a medical apparatus includes a first switching member adapted to select an assigned operating function of the medical apparatus; and a second switching member adapted to permit the selecting of the assigned operating function of the first switching member. The second switching member is adapted such that it has a detection space in which it detects a presence of an operating object; and the first switching member is arranged in the detection space of the second switching member.

A drive circuit for a DC latching device includes a battery, a storage element, and a plurality of switches connecting the battery to the storage element for charging the storage element from the battery and discharging the storage element into the coil of a DC latching device. The drive circuit further includes components for determining a state of the DC latching device. The drive circuit may include components for terminating the discharge of the storage element into the coil of the DC latching device in response to determining that the DC latching device has changed states to add reliability to the system and reduce energy consumption.

A solid state power control (SSPC) controls flow of current from a power bus to an inductive load. The SSPC utilizes load sharing, in which a plurality of current supply paths are connected in parallel to control and share the flow of current between the power bus and the inductive load. Each current supply path includes a main power switching field effect transistor (FET); a balance resistor, and a secondary FET. The balance resistor is connected between the main FET and the load. The secondary FET shunts the balance resistor when the main FET is turned on, and allows current flow through the balance resistor during a turn-off time of the main FET. The balance resistor modulates gate-source voltage of the main FET in order to compensate for gate-source threshold differences among the main FETs that could lead to unequal current sharing during the turn-off period.

Circuitry and methods related to switching power are provided. One of a plurality of current-limited power distribution switches is enabled in accordance with a hierarchical scheme depending upon the respective states of plural power sources. The power source having the greatest available load carrying capacity is thus coupled to a power node for provision to load entities. Servers, computing devices, printers, and other apparatus can include such selective power provisioning.

An apparatus for use in a power delivery system, the apparatus comprising: a DC circuit breaker having first and second terminals and configured to automatically switch from a closed state to an open state during an overcurrent condition; a disconnector switch in series with the DC circuit breaker, the disconnector switch having a first terminal for connecting to a first polarity terminal of a DC power supply, a second terminal for connecting to a second polarity terminal of the DC power supply and a common terminal connected to the first terminal of the DC circuit breaker, the disconnector switch having at least a first position in which the first terminal is connected to the common terminal and a second position in which the second terminal is connected to the common terminal; and an interlock mechanism coupled to the DC circuit breaker and the disconnector switch, the interlock mechanism configured to disable the DC circuit breaker from automatically switching from the closed state to the open state during the overcurrent condition when the disconnector switch is in the second position.

A power control device includes a connector, a detecting module, a control module, a first output module, a second output module, a first switch module, and a second switch module. The detecting module measures a current and outputs different signals according to a comparison result between the current and a preset value. The first output module and the second output module are selectively used to supply power for the connector according to a value of the current.