Thanks for all the answers. In the past I have used TO-92 versions for their current capability. Maybe I can push the wattage further by using a suitable heat-sink. Thanks. Chetan Bhargava http://microz.blogspot.com On Tue, Feb 18, 2014 at 12:23 AM, IVP wrote: > > Are these germanium or silicon? > > Silicon, as far as I know > > > What would be the advantage of using the TO-18 package over > > TO-92 package? > > A little easier to heatsink ? Circular clip-on transistor radiators used > to be quite common to see on boards (in the olde days of RCA- > and Texas-branded TO-5), not so much these days > > One not-so-obvious use of a TO-18 package is that you can cut the > top off to expose the die and use it as an opto-transistor. Works > quite well. Can be done with a TO-3 too, although it's not very > good because a power transistor needs a lot of base current > > Joe > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .