Pulse width of successive output pulse is automatically varied in cycle pattern over an interval of nominally 6.5 seconds.

• Pulse width decreases linearly over a period of 0.5 seconds from the control setting value to a value which is 60 percent less.
• This narrower pulse width is maintained for two seconds and then increased linearly over a 0.5 second period to its original value.
• Pulse width in maintained for 3.5 seconds at the control setting value. The cycle is then repeated.