Shunt (electrical)

In electronics, a shunt is a device which creates a low-resistance path for electric current, to allow it to pass around another point in the circuit. The origin of the term is in the verb 'to shunt' meaning to turn away or follow a different path.Low-side insertion can eliminate common mode voltage, but not without drawbacks.High-side insertion resolves low-side drawbacks, but guarantees common mode voltage.Isolated amplifiers resolve all the difficulties and limitations with high- or low-side current shunt measurements. In electronics, a shunt is a device which creates a low-resistance path for electric current, to allow it to pass around another point in the circuit. The origin of the term is in the verb 'to shunt' meaning to turn away or follow a different path. One example is in miniature Christmas lights which are wired in series. When the filament burns out in one of the incandescent light bulbs, the full line voltage appears across the burnt out bulb. A shunt across the burnt out filament will then short out to bypass the burnt filament and allow the rest of the string to light. If too many lights burn out however, a shunt will also burn out, requiring the use of a multimeter to find the point of failure. In photovoltaics, the term is widely used to describe an unwanted short circuit between the front and back surface contacts of a solar cell, usually caused by wafer damage. A gas-filled tube can also be used as a shunt, particularly in a lightning arrestor. Neon and other noble gases have a high breakdown voltage, so that normally current will not flow across it. However, a direct lightning strike (such as on a radio tower antenna) will cause the shunt to arc and conduct the massive amount of electricity to ground, protecting transmitters and other equipment.