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Unread 02-05-2007, 22:43
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David Brinza David Brinza is offline
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Re: Voltage regulator--how to mount?

Quote:
Originally Posted by Al Skierkiewicz View Post
Jbot,
The 7805 series regulators have the center pin and the tab at the same potential, i.e. power supply common.
As Al points out, the 7805 case (and mounting tab) is tied to the center pin (power supply common). For some applications, you might need to isolate the regulator from the chassis. (In FIRST, for example, the robot chassis is required to be isolated from the +12VDC AND return/ground). There are thin mica insulators available for the TO-220 package that will provide electrical isolation with minimal thermal resistance. If you use your chassis as a heat sink and wish to keep it isolated from the power supply, you should use one of these mica insulators - with some thermal compound to improve the thermal conductivity between the regulator and heat sink.
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