1.   The drill has variable speeds.

2.   The only controls are a variable speed dial mounted on the top of the trigger, and a small lock-on button.

3.   The transition from Romanesque to Gothic proceeded at a variable speed in differing countries.

4.   New chip technology that will give a variable speed drive is also being introduced with a replacement control panel.

5.   Two machines already have variable speed drives.

6.   And your first major purchase should be a variable speed drill-driver of good quality.

7.   Equipment that contains variable speed motors can also cause problems.