The Governor is a device created by Stephen Bartowski. Stephen learned that continued use of flashing is akin to a computer circuit being overheated. So he created the Governor, a device that governs his neural network and prevents the Intersect from causing dementia and eventual insanity.
He also created one for Chuck for the Intersect 2.0. It appears that Chuck has learned how to make a governor by season 4. He is seen to have 3 of them in his room, despite there only being 1 left at the end of season 3. It is unknown if Chuck gave one to Morgan after "Chuck Versus the Cliffhanger".
We could conclude that whilst the Intersect 2.0's side effects manifest sooner, a previous Intersect (like the First Intersect) does cause negative effects after a long period of time. Whilst the first Intersect didn't seem to cause negative effects for Chuck, Orion's Intersect, which had been inside Orion's head for a lot longer, was causing him problems, therefore requiring him to have a governor to control it.
In the final beach scene of Chuck versus the Goodbye, as Chuck moves his hand to kiss Sarah, we see him wearing a watch that appears to be a Governor. It is possible that the Intersect version he uploaded from the sunglasses does not have the fix that Ellie had made when correcting their dad's Intersect, or Chuck has gotten so used to wearing the watch (or as a reminder of his father) that he wears it as part of his persona, even though he doesn't need its special function.
- Chuck's governor is a Rolex Oyster Perpetual with California Dial face.