Abstract: To provide a fuel cell system configured to appropriately measure the AC impedance of a fuel cell. A fuel cell system wherein the controller controls ON and OFF of the switches of n phases; wherein the controller operates the switches of the n phases at different phases, and the controller operates the switches of the n phases at the same duty ratio; wherein the controller operates the switches of the n phases at different duty ratios, when the controller determines that a specific condition is met; and wherein the controller measures the AC impedance of the fuel cell from the current waveform and voltage waveform of the fuel cell.

Abstract: There is provided a fuel cell system in which a constantly accurate impedance measurement is made possible regardless of a response characteristic of the voltage converting device. A superimposed signal analysis section analyzes an impedance measuring signal after passing through a DC/DC converter to thereby notify a superimposed signal amplitude control section of an analysis result. A superimposed signal amplitude control section controls an amplitude value of the impedance measuring signal generated by a superimposed signal generating section based on the result notified from the superimposed signal analysis section.

Abstract: A permanently locking ring binder includes a housing, a pair of hinged plates within the housing, each supporting a plurality of ring segments arranged so that, when the plates are in one position, the ends of the ring segments are spaced apart, so that one can insert loose-leaf papers over the segments, and a second position, in which the ends of opposing ring segments meet, forming closed rings for retaining the papers. The binder has an initially inactive lock which can be activated once papers have been placed in the binder, to prevent movement of the rings to their open position. The lock cannot be manually deactivated.

Abstract: A binder comprises suspension bars, each defining a channel with apertures leading into the channel adjacent the ends thereof. Flexible support elements are threaded through holes in sheets of paper to be received in the binder so that the paper is carried upon the elements. The channel in each suspension bar is formed and dimensioned so as to releasably retain the ends of each element therein without the need for separate retaining means. The binder is assembled by passing the ends of the elements through the apertures and pushing them into the channel where they are held in place.

Abstract: In a folder for receiving documentary material, which is provided with profile bars (3) and slides (6) guided on these for retaining thread-on wires (5) insertable through orifices in the profile bar (3), a cam (9) located on the profile bar is used to retain the slide (6) in a filing position, and this cam is formed by a profile-bar bottom section punched out of the profile bar (3) and extending obliquely upwards towards the end of the profile bar and makes it possible to retain especially securely an engagement stop (17) which is located on the slide (6) and which, if required, can be lifted by the user over the cam (9) in order to displace the slide (6) towards the center of the profile bar (3).

Abstract: A data binder having compression bars forming longitudinal rails and a center channel, flexible posts securing data sheets between compression bars and a retaining slide member embracing the rails to hold the bent over posts in place. Each end of said retaining slide member includes a flare at the end of the center groove for receiving the post. The guide groove facilitates insertion of the post into the retaining slide member.