Understood but there has got to be more to it that my mind is not absorbing. The FQA32N20C spec sheet gives 1700 pf but they are making the waveform much softer than the FQA34N20's spec'd at 2400 pf
Millar feedback capacitance The multiplication of Gate-Drain capacitance due to negative feedback. Don't just look at Cgs, but also at Cgd Andy www.g4jnt.com On Fri, 30 Nov 2018 at 15:12, N1BUG
All I know is this amp had very little drain ringing and worked well with FQA34N20 FETs but it is not happy with FQA32N20. I slowly increased drain voltage but at 200W out (of a kilowatt deck), there
Paul Ringing of FETS is an Early Warning sign for a Big Bang There should be no ringing or singing. g3kev All I know is this amp had very little drain ringing and worked well with FQA34N20 FETs but i
Paul Use the DECCA 5501 bridge cct and you will not have a problem, no ringing, singing or dancing. 73 gl de mal/g3kev All I know is this amp had very little drain ringing and worked well with FQA34N
Hi Paul, In one of my early PA designa i also used an IR2110 to drive FETs having 4 nF gate capacity. At 137 kHz the driver became quite hot and the total life time was just about 20 hours. In my opi
Hello Stefan, Any chance of a few photos of the H Bridge amp construction please? I take it the BF862's in the optocoupler feeds act as current limiters? Any reason you didn't just use resistors inst
Hello Chris, LF I was so frustrated I did not get out the camera to take photos of the scope traces. But I promise before I remove these FETs I will do that and post some waveforms with the original
Hi Chris, Am 02.12.2018 18:01, schrieb Chris Wilson: Any chance of a few photos of the H Bridge amp construction please? OK, here are some impressions ;-) Outside: http://www.iup.uni-heidelberg.de/sc
Hi Chris, Wow, i'm impressed. There seem to be really better FETs nowadays, and they are quite cheap! Here is another parametric search from RS UK: https://uk.rs-online.com/web/c/semiconductors/discr
