Densei-Lambda Kabushiki Kaisha

Hitachi, Ltd.

Densei Lambda K.k.

Satoshi Tomioka

Hideho Yamamura

Naoki Maru

Motoharu Ueguri

In a redundant configuration with multiple power sources connected in parallel to enhance reliability, a power source in which an overvoltage failure occurred has been difficult to identify and unable to be deactivated, which has impeded the improvement of reliability. However, it has become possible to deactivate selectively only the power source in which an overvoltage failure has occurred, by providing a independency-discrimination circuit that identifies the occurrence of the overvoltage failure by use of the state of a parallel operation control circuit, and connecting the independency-discrimination circuit, an overvoltage detection circuit, and a connection circuit.

Overvoltage protection circuit, and power source, power supply system and electronic apparatus using the overvoltage protection circuit

A switching power supply which feeds energy stored in a choke coil to a load through a freewheeling element when a switching element turns off. The switching power supply includes a freewheeling MOSFET serving as the freewheeling switch element which operates synchronously with the switching element and a surge voltage prevention circuit . The surge voltage prevention circuit detects a timing for a current to flow in the direction that a body diode of the freewheeling MOSFET conducts when an operation stoppage signal to the switching element is outputted, and then turns off the freewheeling MOSFET at the timing.

Switching power supply

An on-board mounting electronic apparatus including an apparatus body made up of a main board and terminal pins for connection with a circuit board The terminal pins extend from an underside of the main board A heat dissipation plate is arranged on an upper surface of heat generating components mounted on the main board The heat dissipation plate is thermally connected with the surface of the heat generating components Such structure may be applied to an on-board mounting electric power supply as well.

Growing community of inventors

Nagaoka, Japan

Satoshi Tomioka