For private use I prefer to buy two cheap Chinese devices than a single expensive one. I just do not use them all that often and prefer value and flexibility over quality. So I got myself a Hantek DSO5102P 100 Mhz digital storage oscilloscope, which I upgraded to 200MHz and coupled with my laptop using a nice DSO-USB Tool by Peter Dreisiebner. And I got myself a cheap Korad KD3005D digital lab power supply (30V, 5A), although I do not rely all that much on its readings. And some more.

Except value, there is one more thing all these devices share: they are loud. Especially the power supply made me crazy. I found a nice description how to silence it by Leniwiec ("the lazy one" in Polish). So I looked inside the power supply and ordered a couple of AIRPAX BT-67F050 bimetalic switches (TO-220, Tclose = 50°C) and a SK81/100/SA 100x100 mm Fischer Heatsink. I find the name AIRPAX really well-chosen.

I simply installed the bimetalic switch with some thermal grease on an existing "heatsink" and in the fan connection, and used the Fischer heatsink for another project.

Silence is golden now... And who is the lazy one?