Listen to atomarc. If the 2 terminals in the hole look like this: [||] ,it needs an external regulator.

If they look like this: [--] ,it is internally regulated.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.