On Sun, Jun 30, 2013 at 02:10 PM, G?ran Krusell <goran.krusell@...> wrote:
Hi Tony,
I used the BU208A from ST with good result.
G?ran
On Sun, Jun 30, 2013 at 02:10 PM, G?ran Krusell <goran.krusell@...> wrote:
Hi Tony,
I used the BU208A from ST with good result.
G?ran
The BU208A is *>not<* a good idea. With a full set of modules the current load pushes past the SOA at the duty cycle used by the power supply. Its gets way too hot.. And once it gets hot it derates further. At 200V it exceeds the current pulled by a fully loaded 7904. This leads to thermal runaway which will then lead to a 200F back heat sink and eventual transistor failure. It will work tho, for short periods..
I am looking into upgrading this transistor to a more powerful one. I have ordered up some BUX48A's. I dont know if these work yet tho.. I will report back here once I have a well tested better then orginal sub..
MAYBE.. Untested so far.. I get them this week
