Hello Stefan and Andy,
Friday, November 25, 2016
Thanks for the replies, I see now how similar they are to an H Bridge
in a SMPS, and I have also found some good info from the audiophile
world on H Bridge outputs. And I see now how the Source and Drain naming
would have occurred, it's down to the review of positive and negative
current flow in light of better understanding of electron flow.
I just wish I had got into this hobby when I was younger with a more
receptive and retentive brain!
Thanks again, i have an RFI question, but I'll start a fresh topic.
Best regards,
Chris 2E0ILY mailto:[email protected]
> Forget my comments about gate resistors, you said for a non linear
> (switching) design. I was talking about linear amps
> As the last post said, small values to damp oscillations if any are
> needed at all - assuming a proper square wave drive, they shouldn't be.
> 'JNT
> On 25 November 2016 at 14:16, Andy Talbot <[email protected]> wrote:
> continuing...
> The gate resistor just has to swamp teh Xc of the gate capacitance
> in a linear amp, to make it look clean and resistive at the input.
> So, for example, assume 2000pF Cgs at 475kHz. Xc = 167 ohms. SO
> a shunt R of say 30 to 50 ohms will dominate.
> If you were really daring you might think it possible to resonate
> out the Gate C and then get really high gain. ( Don't do this with
> an expensive FET). But worth trying the experiment to see - power
> oscillators take on a completely new meaning if you try it.
> drain / source... emitter / collector. They're just legacy
> names. You just know what they are without thinking of the actual
> meaning. Although, I suppose, if you think of electron flow...........
> 'JNT
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