17 Dec
2011
17 Dec
'11
10:36 a.m.
On 12/16/2011 05:07 PM, Tony Duell wrote:
Isn't that basically what I said?
Nope. His final circuit didn't use the FET.
Ah yes, of course. I guess the fact that the channel reisstance of a FET
is not quite constant casued enough distortion to make it worse than the
good old filament lamp.
I thoguht in the end he managed to get the FET circuit
to be better than
the light bulb, but it took a lot of work (and probably wasn't worth it).
No. His initial attempt with a FET didn't perform all that well (if
memory serves), but in the end his very complex circuit with (I think)
three high-end opamps and an LED-driven photocell did end up
outperforming the incandescent lamp design. I didn't; realise he used an LED + LDR in the
cirucit. It's a long time
sinc eI read the book, so I must have forgotten that. I'd sort-of assumed
it used only purely electronic (as opposed to optoelectornic) parts
Yup. Those Vactrol analog optoisolators sure are neat. Don't bother; I've already found it.
It's "Troubleshooting Analog
Circuits", ISBN 0750694998.
THat sounds right.
[1] I don't necessarily agree with everything
they write, but it's all
worth reading. To be abvle to disagree with it you have to understand it,
and you'll learn a lot by so doing...
That's good thinking.