Patent ID: 7582989

Claim:
A safety relay comprising: a first relay including a first relay contact and a first relay coil to change the state of the first relay contact when the first relay coil is energized; a first switch coupled in series with the first relay coil; a second relay including a second relay contact and a second relay coil to change the state of the second relay contact when the second relay coil is energized; a second switch coupled in series with the second coil, wherein the first switch and the first relay coil are coupled in parallel with the second switch and the second relay coil between a first node and a second node, and wherein the first relay contact and the second relay contact are coupled in series between a third node and a fourth node; a third relay including a third relay contact and a third relay coil to change the state of the third relay contact when the third relay coil is energized; and a third switch coupled in series with the third coil, wherein the third switch and the third relay coil are coupled in parallel with the first switch and the first relay coil between the first node and the second node, and wherein the third relay contact is coupled in series with the first relay contact and the second relay contact between the third node and the fourth node.