Abstract: A DC-DC power converter comprises: first, second and third input nodes for connection to one or more DC input power sources; a pair of upper switches TH1, TH2 connected in series between the first and second input nodes; and a pair of lower switches TL1, TL2 connected in series between the second and third input nodes. An output port is connected, via one or more output capacitors and one or more output inductors, to an upper switching node between the pair of upper switches and a lower switching node between the pair of lower switches TL1, TL2. The converter is connectable to a pair of DC input power sources, with a first DC input power source connected between the first and second input nodes and a second DC input power source connected between the second and third input nodes, and, when so connected, the pair of upper switches TH1, TH2 and the pair of lower switches TL1, TL2 are switchable to provide DC output power at the output por.

Abstract: A DC-DC power converter comprises: first, second and third input nodes for connection to one or more DC input power sources; a pair of upper switches TH1, TH2 connected in series between the first and second input nodes; and a pair of lower switches TL1, TL2 connected in series between the second and third input nodes. An output port is connected, via one or more output capacitors and one or more output inductors, to an upper switching node between the pair of upper switches and a lower switching node between the pair of lower switches TL1, TL2. The converter is connectable to a pair of DC input power sources, with a first DC input power source connected between the first and second input nodes and a second DC input power source connected between the second and third input nodes, and, when so connected, the pair of upper switches TH1, TH2 and the pair of lower switches TL1, TL2 are switchable to provide DC output power at the output por.

Abstract: Systems and apparatus for monitoring physiological electrical activity of an individual include a first electrode unit for receiving a first signal indicative of electrical activity at a first location on a body of the individual and a second electrode unit for receiving a second signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units may be operated in a field-sensing mode wherein the electrode unit is placed on or in proximity to the individual's skin. The first and second electrode units comprise a capacitive sensor element, and the capacitive sensor element of each of the electrode units comprising an electrodynamic sensor which is sensitive to electromagnetic waves; and an antenna comprising an electrically conductive radiating element for receiving electromagnetic waves.

Abstract: Systems and apparatus for monitoring heart muscle activity of an individual include a first electrode unit, for receiving a first signal indicative of electrical, activity at a first location on a body of the individual and a second electrode unit for receiving a second, signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units is configurable to operate in a field-sensing mode wherein the electrode unit is placed on or it! proximity to the individual's skin, and a current-sensing mode wherein the electrode unit is coupled to a resistive sensor sensing element placed directly on the individual's skin. The field-sensing mode can be either non-contact field-sensing mode.

Abstract: Systems and apparatus for monitoring physiological electrical activity of an individual include a first electrode unit for receiving a first signal indicative of electrical activity at a first location on a body of the individual and a second electrode unit for receiving a second signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units may be operated in a field-sensing mode wherein the electrode unit is placed on or in proximity to the individual's skin. The first and second electrode units comprise a capacitive sensor element, and the capacitive sensor element of each of the electrode units comprising an electrodynamic sensor which is sensitive to electromagnetic waves; and an antenna comprising an electrically conductive radiating element for receiving electromagnetic waves.

Abstract: Systems and apparatus for monitoring physiological electrical activity of an individual include a first electrode unit for receiving a first signal indicative of electrical activity at a first location on a body of the individual and a second electrode unit for receiving a second signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units may be operated in a field-sensing mode wherein the electrode unit is placed on or in proximity to the individual's skin. The first and second electrode units comprise a capacitive sensor element, and the capacitive sensor element of each of the electrode units comprising an electrodynamic sensor which is sensitive to electromagnetic waves; and an antenna comprising an electrically conductive radiating element for receiving electromagnetic waves.

Abstract: Systems and apparatus for monitoring heart muscle activity of an individual include a first electrode unit, for receiving a first signal indicative of electrical, activity at a first location on a body of the individual and a second electrode unit for receiving a second, signal indicative of electrical activity at a second location on the body of the individual. Each of the first and second electrode units is configurable to operate in a field-sensing mode wherein the electrode unit is placed on or it! proximity to the individual's skin, and a current-sensing mode wherein the electrode unit is coupled to a resistive sensor sensing element placed directly on the individual's skin. The field-sensing mode can be either non-contact field-sensing mode.

Abstract: A system includes a fuel cell stack, a power communication path, a first controller and a second controller. The fuel cell stack generates electrical power, and the power communication path is coupled between the fuel cell stack and a load of the system to communicate the electrical power to the load. The power communication path includes a switch, which is operable to selectively couple the fuel cell stack to the load and isolate the fuel cell stack from the load. The first controller has a first response time to control the fuel cell stack and control the power communication path. The second controller has a second response time, which is significantly less than the first response time to monitor the power communication path for a fault condition and take corrective action in response to detecting the fault condition.

Abstract: A method and apparatus for digitally controlling the average input current of a switch mode power supply are disclosed. In preferred embodiments, the switch mode power supplies are DC-DC converters. One aspect of the invention relates to a method for controlling the switch of a switch mode power supply by digitally sampling the input current once during each power supply switching cycle at a time that is synchronized with the switching cycle. The predetermined time at which the input current is sampled may be midway through the time that the switch is in the “ON” state. This midway time may also be delayed slightly to compensate for delays associated with the switch.

Abstract: A self-regulated system and method for cooling switching power supplies that take parasitic effects of switching which would normally be dissipated as heat in a typical RC snubber circuit, and use that waste energy to power a cooling element to automatically cool semiconductor switches of the power supplies and any DC or AC systems. The cooling element can be a variable speed fan, a liquid pump, a Peltier device, or the like, in which case the system and method provide power to the cooling element in proportion to the amount of current delivered to the power supply, and so the cooling system automatically adjusts itself to the level needed to protect the power supply.

Abstract: A self-regulated system and method for cooling switching power supplies that take parasitic effects of switching which would normally be dissipated as heat in a typical RC snubber circuit, and use that waste energy to power a cooling element to automatically cool semiconductor switches of the power supplies and any DC or AC systems. The cooling element can be a variable speed fan, a liquid pump, a Peltier device, or the like, in which case the system and method provide power to the cooling element in proportion to the amount of current delivered to the power supply, and so the cooling system automatically adjusts itself to the level needed to protect the power supply.