Topic
Wetting current
About: Wetting current is a research topic. Over the lifetime, 44 publications have been published within this topic receiving 282 citations.
Papers
10 Jun 2008
TL;DR: In this article, a contact resistivity model was developed that is a function of contact pressure, the hardness of the softer contact member, average bulk resistivity, and contact constants.
Abstract: Adequate contact pressure needs to be applied at electrical contacts to overcome contact separation force due to current constriction effects. In the railgun operation, the initial contact pressure is provided by the interference pressure between the armature and the rail. As the magnetic field is established in the bore, the electromagnetic force provides the contact pressure, as the initial contact pressure reduces due to wear or contact melting. Excessive initial contact pressure may delay the motion of the armature and cause overheating of the armature. On the other hand, insufficient initial pressure would result in contact separation of armature and rail. The contact interface is never perfectly smooth. It only contacts at discrete asperities at micro scale and at discrete points due to deformation of the contact interface at macro scale. The interface characteristics are different from the bulk behavior. A detailed model of contact resistivity is essential to compute the interfacial current density and temperature distributions accurately. A contact resistivity model was developed that is a function of contact pressure, the hardness of the softer contact member, average bulk resistivity, and contact constants. The model was implemented into the code EMAP3D. This paper presents the simulation results of the start-up of a sample railgun with and without contact resistivity.
66 citations
Patent•
28 Nov 2000TL;DR: In this paper, a method for improving the consumption of energy consumption of a switch input current circuit that contains resistor elements is described. But the method is limited to a single switch and does not cover all switches.
Abstract: The invention relates to a method and to a corresponding device for improving the consumption of energy of a switch input current circuit that contains resistor elements. The inventive method comprises the following steps: providing a wetting current on at least one switch by means of a corresponding resistor element, modulating the wetting current with a pulse-width modulation signal to provide a reduced average voltage that is supplied to the corresponding resistor element, thereby reducing the consumption of energy of the electric circuit.
33 citations
TL;DR: The instability of Au-Au micro/nano-contact behavior during the initial stage of contact formation is comprehensively investigated for the first time and a strong correlation between contact resistance fluctuation at the initial contact stage and the presence of a hydrocarbon alien film on the contact surface is revealed.
Abstract: The metal contact is one of the most crucial parts in ohmic-contact microelectromechanical (MEMS) switches, as it determines the device performance and reliability. It has been observed that there is contact instability when the contact force is below a threshold value (minimum contact force). However, there has been very limited knowledge so far about the unstable electrical contact behavior under low contact force. In this work, the instability of Au-Au micro/nano-contact behavior during the initial stage of contact formation is comprehensively investigated for the first time. It has been found that the alien film on the contact surface plays a critical role in determining the contact behavior at the initial contact stage under low contact force. A strong correlation between contact resistance fluctuation at the initial contact stage and the presence of a hydrocarbon alien film on the contact surface is revealed. The enhancement of contact instability due to the alien film can be explained within a framework of trap-assisted tunneling.
18 citations
Patent•
21 Jul 1942
TL;DR: In this article, an improvement of electrical contacts of silver was proposed. But the improvement was concerned with the improvement of the electrical contacts with high current carrying capacity and low contact resistance.
Abstract: This invention relates to electrical contact elements suitable for use in making and breaking electric current, and is concerned in particular with the improvement of electrical contacts of silver. Electrical contacts should have high current carrying capacity and low contact resistance. They...
13 citations
Patent•
28 May 1990
TL;DR: In this paper, the authors proposed to prevent defective continuity and reduce the consumption current by feeding a large current to a contact when the contact is in the conductive state, and feeding a small current when the nonconductive state of the contact was detected after the large current was fed for a preset period.
Abstract: PURPOSE: To prevent defective continuity and reduce the consumption current by feeding a large current to a contact when the contact is in the conductive state, and feeding a small current when the nonconductive state of the contact is detected after a large current is fed for a preset period. CONSTITUTION: An input circuit is constituted of a resistor 10 inserted between the cathode of a diode 2 and a resistor 4 and a capacitor 11 connected to the connection point between the resistors 10, 4 at one end and grounded at the other end. When a contact 5 is turned on, the current (i) charged to the capacitor 11 flows through this contact immediately after it. This current (i) is large and breaks an oxidation film. The consumption current I in the stationary state then flows through the contact 5. If the resistance R of the resistor 4 is made smaller than the resistance nR of the resistor 10, the consumption current I can be decreased. When a large current is fed immediately after the contact 5 is turned on and a small current is fed thereafter, defective conduct can be prevented, and the consumption current can be reduced. COPYRIGHT: (C)1992,JPO&Japio
12 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2017 | 1 |
| 2016 | 2 |
| 2015 | 4 |
| 2014 | 5 |
| 2013 | 7 |