Tantalum capacitor

About: Tantalum capacitor is a research topic. Over the lifetime, 2432 publications have been published within this topic receiving 26709 citations.

High charge, low leakage tantalum powders

Abstract: Tantalum powders for electrolytic capacitors having improved electrical capacity and low direct current leakage characteristics are produced by the introduction of combinations of carbon, nitrogen and sulfur-containing materials.

Capacitor and method for producing the same

Abstract: A capacitor including a dielectric film of a metal oxide, in which two electrodes contact with the surfaces of the dielectric film, and at least one of the electrodes is a conductive metal compound to which oxygen is added. A method for producing the capacitor is also disclosed.

Method and apparatus for testing electrolytic capacitors

Abstract: An Equivalent Series Resistance (ESR) measurement device for testing electrolytic capacitors without removing the test capacitor from the circuit in which it is being used and without first discharging the test capacitor prior to testing. A low voltage AC ohmmeter, which operates at a frequency of approximately 100 KHz, is used as the measurement device for the in-circuit testing of the ESR and thus as an indication of the status or usability of the electrolytic capacitor being tested. A current-blocking capacitor is placed in series with the electrolytic capacitor being tested to allow in-circuit testing without damaging the meter since it blocks any DC charge remaining on the test capacitor. A pair of oppositely poled diodes are coupled in parallel across the terminals of the meter to protect the meter from surge currents and the like and a resistor is coupled in parallel with the test capacitor to provide a discharge path for discharging the series blocking capacitor when the electrolytic capacitor is removed from testing. The ESR meter itself is designed with two operational amplifiers forming an oscillator whose output is relatively immune from fluctuations in supply voltage. An amplifier network including three operational amplifiers is provided to amplify the ESR signal to a usable level. A peak-to-peak detector circuit is used which employs an operational amplifier having a supplemental feedback resistor which reduces the phase shift at the output of the operational amplifier to enable the peak detector diodes to perform their conventional functions. The two outputs of the peak detector are connected to two DC amplifiers and a conventional meter movement is driven differentially by the DC amplifiers to provide a visual readout of the measured ESR of the test capacitor for evaluation purposes and the like.

Surveillance devices with multiple capacitors

Abstract: The present invention relates to surveillance and/or identification devices having capacitors connected in parallel or in series, and methods of making and using such devices. Devices with capacitors connected in parallel, where one capacitor is fabricated with a relatively thick capacitor dielectric and another is fabricated with a relatively thin capacitor dielectric achieve both a high-precision capacitance and a low breakdown voltage for relatively easy surveillance tag deactivation. Devices with capacitors connected in series result in increased lateral dimensions of a small capacitor. This makes the capacitor easier to fabricate using techniques that may have relatively limited resolution capabilities.

Electrolytic capacitor and method of producing the same

Abstract: The present invention provides an electrolytic capacitor having a large capacitance sufficiently close to its design capacitance, and a method of easily producing such an electrolytic capacitor. In this method, a cathode-side conductive polymer layer or a electrolyzing electrode is formed on at least one side surface of an anode valve metal foil having through holes 20 and a coarsened surface, electrolysis is carried out in a conductive monomer solution, with the polymer layer used as the anode, and an electrolytically-formed conductive polymer layer is formed on the surface of the dielectric oxide film of the valve metal foil, thereby obtaining an electrolytic capacitor. As a result, it is possible to easily obtain an electrolytic capacitor having a large capacitance sufficiently close to its design capacitance.