The TRIAC is used in single phase AC loead control, for example in heating, light and motor control. The circuit is relatively simple, but not its design and control.
As soon as the capacitor voltage gets alrger than the on voltage of the DIAC, the TRIAC will start conducting. The vlaue of trigger votlage of the diac can be set in the DIAC component.
Change R2 from 1k to lager values ,like 2k, 5k, 10k 22k, 68k to control the on time
The light dimmer is greatly simplified . However a snubber across the TRIAC is required to filter the voltage spikes.
For motor control, the TRIAC circuit is enhanced with more filter components. Change R3 from 1k to 68k to control the speed of hte motor. This circuit is typically found in vacuum cleaners.
A softstarter is used in industrial motor control to reduce the size of the currents durin start up of a three-phase induction machine. The simulation below sows the difference between a directly to the grid connected induction machine and one operatiing from a softstarter. Notice that the maximum current in the case of the softstarter is around 300 ampere, while for the directly to the grid connected machine a start-up current of around 1000 Ampere is flowing.
For single-phase and three-phase control, either a Triac or complete softstarter is used. Notice that the Diac component can be found under the section of components/circuit/semiconductor, while the triac has to be selected from components/library/semiconductor/triac.