Tuesday, July 28, 2009

Transistor matching

After the carrier block has finished, it's time to match the transistors.

I have built a simple curve tracer from Elektor Electronics (Feb. 2009).

More info about this Transistor Curve Tracer,

http://www.elektor-electronics.co.uk/magazines/2009/february/transistor-curve-tracer.810360.lynkx


And this is mine.




A sample screenshot of a typical 2SJ49 mosfet,

Wednesday, July 15, 2009

It looks like this.......

Have the TO3 transistor mounted on the carrier block and it fits very well.




More tests to follow.



Thursday, July 9, 2009

Making a new poweramp

I'm in the process of making a new solid state power amp that uses the old but good "Lateral" mosfet by Hitachi. Since they are in To3 package, mounting them onto the heatsink will need some work. I have decided to make a "carrier block". The output transistors will all sitting on the carrier block and then the block will be mounted on the heatsink.

Machining of the carrier block by a small CNC:





This is a test version which will hold two TO3 transistor. The milled block look like this:




We will need a flat surface to ensure good thermal contact with the heatsink, some touch up is then required.




Not too bad I think. :-)