Three Phase ACDigital ArtistsUpdated on Nov 27, 2019 View more like this | Visit CHANHASSEN, MN | Contact Control Concepts Inc. |
Three Phase, Zero Cross:
The term Zero-Cross (synchronous operation of SCR's) is derived from the fact that the SCR's are turned on only when the instantaneous value of the sinusoidal wave is zero. In Zero-Cross operation, power is applied for a number of continuous half-cycles and then removed for a number of half-cycles to achieve the desired load power in the same manner as power would be controlled with a mechanical switching device. The frequency of the on-off cycles can be extremely fast because there is no limit to the number of switching operations the SCR can perform.
3 Phase, Phase Angle:
In phase-angle control, each SCR of the back-to-back pair is turned on for a variable portion of the half-cycle that it conducts. Power is regulated by advancing or delaying the point at which the SCR is turned on within each half cycle. Light dimmers are an example of Phase-Angle control.
The term Zero-Cross (synchronous operation of SCR's) is derived from the fact that the SCR's are turned on only when the instantaneous value of the sinusoidal wave is zero. In Zero-Cross operation, power is applied for a number of continuous half-cycles and then removed for a number of half-cycles to achieve the desired load power in the same manner as power would be controlled with a mechanical switching device. The frequency of the on-off cycles can be extremely fast because there is no limit to the number of switching operations the SCR can perform.
3 Phase, Phase Angle:
In phase-angle control, each SCR of the back-to-back pair is turned on for a variable portion of the half-cycle that it conducts. Power is regulated by advancing or delaying the point at which the SCR is turned on within each half cycle. Light dimmers are an example of Phase-Angle control.
