Heat sink DIY for TO92
Apr 27, 2013 13:41:22 GMT
Post by Deleted on Apr 27, 2013 13:41:22 GMT
Well, I did it again, missed bits on my orders for the A Class 15w build 
I omitted heat sinks for the BC327/337 TO92 packages. Can't obtain anything locally whether it be TO92/5/99, curses.
After looking around on the net I saw an idea that seemed OK but needed enhancing so I did the following...
Tools required, plus some malleable metal, copper/steel/ally. I used aluminium of approx. 0.75mm gauge.
I carefully measured a TO92 package then drew a stencil to fit it well and provide the required sinking to transfer to the ally.
Using tin snips, I cut out the shape, made slots to form the fins and create the tabs that would grip the package.
As you're left with a rather curly and twisted affair from the snips, it's best to then straighten and flatten the result with use of long nose pliers and our good friend the hammer!
The fins then need to be bent back over a straight former, the pliers worked nicely.
Using another former placed at the bases of your fins, e.g. I used the edge of a 1mm gauge steel piece. Bend the fins back flat either side of your former.
You should end up with something like this. It may need a little tidying to be aesthetically more pleasing.
Now you need to make the initial bends on the tabs to grip the TO92. Check with a spare or dead TO92 that the bends are accurate and snug.
Keeping said TO92 as a former, complete the bending of the tabs to create a secure fit. Remember you need to remove this package and then fit the sink on the target one so don't close the tabs around the top and bottom of the stunt TO92!
Sorted guvna', bloody bootifal!
...and I'm ready for my close up Mr. DeMille!
I omitted heat sinks for the BC327/337 TO92 packages. Can't obtain anything locally whether it be TO92/5/99, curses.
After looking around on the net I saw an idea that seemed OK but needed enhancing so I did the following...
Tools required, plus some malleable metal, copper/steel/ally. I used aluminium of approx. 0.75mm gauge.
I carefully measured a TO92 package then drew a stencil to fit it well and provide the required sinking to transfer to the ally.
Using tin snips, I cut out the shape, made slots to form the fins and create the tabs that would grip the package.
As you're left with a rather curly and twisted affair from the snips, it's best to then straighten and flatten the result with use of long nose pliers and our good friend the hammer!
The fins then need to be bent back over a straight former, the pliers worked nicely.
Using another former placed at the bases of your fins, e.g. I used the edge of a 1mm gauge steel piece. Bend the fins back flat either side of your former.
You should end up with something like this. It may need a little tidying to be aesthetically more pleasing.
Now you need to make the initial bends on the tabs to grip the TO92. Check with a spare or dead TO92 that the bends are accurate and snug.
Keeping said TO92 as a former, complete the bending of the tabs to create a secure fit. Remember you need to remove this package and then fit the sink on the target one so don't close the tabs around the top and bottom of the stunt TO92!
Sorted guvna', bloody bootifal!
...and I'm ready for my close up Mr. DeMille!
engineering wins out again.
