However with an inductive
load the current ’lags‘ behind the voltage so it is
possible that the current through the triac will not reach
the triacs threshold level before the trigger pulse ends.
This results in unacceptable dimming performance. To
avoid this, dimmers designed for use with wire wound
transformer fed loads use what is known as a hard
firing technique. This ensures that the trigger pulse is
maintained for a long enough period of time to ensure
that the current reaches the device’s threshold level.