Search results
Results from the WOW.Com Content Network
A thin film of oxidation, or an otherwise passivated layer, tends to form in most environments, particularly those with high humidity, and, along with surface roughness, contributes to the contact resistance at an interface. [3] Providing a sufficient amount of wetting current is a crucial step in designing circuits that use switches with low ...
The current induced in a circuit due to a change in a magnetic field is directed to oppose the change in flux and to exert a mechanical force which opposes the motion. Lenz's law is contained in the rigorous treatment of Faraday's law of induction (the magnitude of EMF induced in a coil is proportional to the rate of change of the magnetic flux ...
Electric current can be directly measured with a galvanometer, but this method involves breaking the electrical circuit, which is sometimes inconvenient. Current can also be measured without breaking the circuit by detecting the magnetic field associated with the current. Devices, at the circuit level, use various techniques to measure current:
The current entering any junction is equal to the current leaving that junction. i 2 + i 3 = i 1 + i 4. This law, also called Kirchhoff's first law, or Kirchhoff's junction rule, states that, for any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node; or equivalently:
When the contact is operating under power (wet), the sources of the wear are the result of high current densities in microscopic areas, and the electric arc. [2] Contact wear includes material transfer between contacts, loss of contact material due to splattering and evaporation, and oxidation or corrosion of the contacts due to high ...
The magnetic Lorentz force v × B drives a current along the conducting radius to the conducting rim, and from there the circuit completes through the lower brush and the axle supporting the disc. This device generates an emf and a current, although the shape of the "circuit" is constant and thus the flux through the circuit does not change ...
The use of a "fluid transistor" in microfluidic circuits for manipulating chemical and biological fluids was first investigated by J. Brown in 1980 and later funded in 1984–1988 under NSF Grants 8760730 & 8822197, [4] employing insulating dielectric and hydrophobic layer(s) (EWOD), immiscible fluids, DC or RF power; and mass arrays of ...
When relay contacts open to interrupt a high current with an inductive load, a voltage spike will result, striking an arc across the contacts. If the voltage is high enough, an arc may be struck even without an inductive load. Regardless of how the arc forms, it will persist until the current through the arc falls to the point too low to ...