The ornamental design for an automatic transferswitch, as shown and described.
1. Automatic transfer switch
1.1: Front perspective view
1.2: Front
1.3: Back
1.4: Left
1.5: Right
1.6: Top
1.7: Bottom
Reproduction 1.1is a front perspective view of the automatic transfer switch; reproduction 1.2is a front view thereof; reproduction 1.3is a back view thereof; reproduction 1.4is a left view thereof; reproduction 1.5is a right view thereof; reproduction 1.6is a top view thereof; and reproduction 1.7is a bottom view thereof.
The broken lines depict portions of the automatic transfer switch that form no part of the claimed design.