The model makes sure that an on signal is only passed through if the device was on for a given time thresholdTimer.
When the input signal is set to true the given thresholdTimer starts counting.
After the moment when thresholdTimer is exceeded the
output signal can switch to false but will stay true until the
input value is set to false again. Then again the timer start to
count and the output won't change to true until the timer is
finished again.