Quote:
Originally Posted by Nymrod121
On 79xx series the lead configuration is common/in/out when viewed from the package side (c.f. in/common/out on the 78xx). The 79xx heatsink tab is also connected to the input connection so an appropriate heatsink washer / insulated mounting-bolt/nut will be needed:
|
The way I remember it (and there may be electrical reasons why this is so) is that the most negative connection is the tab (and centre lead). So for a positive regulator (78xx), the tab is common. For a negative regulator (79xx) it's the (-ve) input.
On a negative earth car you can normally have the tab of a 78xx (but not that of a 79xx) in contact with the car body.