shunt (redirected from portacaval shunt)
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1. a railway point
2. Electronics a low-resistance conductor connected in parallel across a device, circuit, or part of a circuit to provide an alternative path for a known fraction of the current
3. Med a channel that bypasses the normal circulation of the blood: a congenital abnormality or surgically induced
4. Brit informal a collision which occurs when a vehicle runs into the back of the vehicle in front
an electrical or magnetic conductor connected in parallel with an electric or magnetic circuit to divert part of the electric current or magnetic flux when it is undesirable or impossible to pass all the current or flux through the circuit. For example, when a shunt is used to extend the measuring range of an ammeter, the current Ix being measured is divided between the shunt and the ammeter in inverse proportion to their respective resistances, Rs and RA; in this case Ix = IA (1 + RA/RS) = IAks, where IA is the value of the current as determined from the ammeter readings and ks is the shunting factor. For convenience in making current measurements, the resistance of the shunt is chosen so that ks is equal to 10,100, or 1000.
Shunts are manufactured in the form of plates, bands, and wires, primarily of manganin or constantan (for electrical shunts) or of a soft magnetic material (for magnetic shunts).
To shove or turn off to one side, as a car or train from one track to another.
A precision low-value resistor placed across the terminals of an ammeter to increase its range by allowing a known fraction of the circuit current to go around the meter. Also known as electric shunt.
To place one part in parallel with another.
A piece of iron that provides a parallel path for magnetic flux around an air gap in a magnetic circuit.
A vascular passage by which blood is diverted from its normal circulatory path; frequently it is a surgical passage created between two blood vessels, but it may also be an anatomical feature.
shuntTo divert, switch or bypass.