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Over the last six months I purchased several copies from Amazon (US warehouse near me), and they were all shipped in a bigger box with no packing material, and were subject to severe damage. Thankfully, none was damaged. Today I received another order. It was finally properly packaged with a shrink-wrapped bottom plate in a larger box.
It was the 5th printing. This one has had hundreds of typos and errors fixed (thanks to many reader's timely notices) and the text, figures, tables and formulas are now largely free from further errors. :-) Just for now, Amazon is selling it for 30% off, or $84 each.
Did you ever get around to fixing Fig. 6.42 on page 416?
It claims to show a full 360 degree all-pass shifter, but the circuit looks like a Wien bridge with incorrect gain-setting resistor values.
It won't do what the text says it does, and Williams and Taylor show rather different circuit - with two op amps - to do the job. My clever friend in Edinburgh has a one op amp circuit that does the 360 degree phase shift, at constant amplitude, but the output amplitude is a constant at roughly one third of the input.
E-mail me and I'll send you the .asc files. I thought that I'd done that si x months ago, but there's no trace of it in my e-mail files, though the rel evant Spice models are dated around the 20th June 2015.
It's obvious enough to me to make me suspect that your publisher may have p ut it in as an anti-piracy device ...
ks like a Wien bridge with incorrect gain-setting resistor values.
er different circuit - with two op amps - to do the job. My clever friend i n Edinburgh has a one op amp circuit that does the 360 degree phase shift, at constant amplitude, but the output amplitude is a constant at roughly on e third of the input.
six months ago, but there's no trace of it in my e-mail files, though the r elevant Spice models are dated around the 20th June 2015.
Huh, yeah that doesn't seem to work. Can you post the *.asc file here?
Or find a link to the two opamp version. (I don't have Williams and Taylor .) Searching the web I can only find the "classic" all-pass.
ooks like a Wien bridge with incorrect gain-setting resistor values.
ther different circuit - with two op amps - to do the job. My clever friend in Edinburgh has a one op amp circuit that does the 360 degree phase shift , at constant amplitude, but the output amplitude is a constant at roughly one third of the input.
t six months ago, but there's no trace of it in my e-mail files, though the relevant Spice models are dated around the 20th June 2015.
You must be the last one left who hasn't ordered at least one copy.
C'mon, get with the program! Some of us have already been back for seconds.
I hear there are marathons where groups of engineers read the first, second and third editions cover-to-cover, or maybe I'm thinking of Star Wars.
--sp
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Best regards,
Spehro Pefhany
Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8
Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48
Is the US warehouse in Illinois? Amazon's a mixed bag for me. Sometimes it delivers the goods, and at other times it only delivers a facsimile of the goods.
What's the best bet, in your opinion, of getting a genuine fifth printing of AoE (and not a first printing masquerading as a fifth printing)? TIA.
I think Amazon has many warehouses, which to some extent operate each with their own inventory, although sometimes they ship from one warehouse to another. I was hoping to see a 4th printing (already had most of the fixes), but was pleasantly surprised to get the recent 5th printing.
The safest place to get the latest printing is to order a copy from Cambridge University Press, but they don't offer any discount.
looks like a Wien bridge with incorrect gain-setting resistor values.
rather different circuit - with two op amps - to do the job. My clever frie nd in Edinburgh has a one op amp circuit that does the 360 degree phase shi ft, at constant amplitude, but the output amplitude is a constant at roughl y one third of the input.
hat six months ago, but there's no trace of it in my e-mail files, though t he relevant Spice models are dated around the 20th June 2015.
ylor.)
From 10k to 2k, which is substantial.
And drop the output amplitude to a fifth of the input amplitude, which puts the circuit in a rather different ball-park from 6.41
And for most real op amps you need to put a capacitor in parallel with the
10k feedback resistor to compensate for the input capacitance of the real o p amp. Sometimes the parallel capacitance of a real resistor is high enough to do the job, and some op amps don't have enough gain-bandwidth for it to be a worry.
We apologize for our initial error in transcribing the circuit.
Genin (see ref to his 1968 paper in the caption of Figure 6.42, I'll email a copy on request) calls his circuit a variation of a Wien bridge. He derives an equation showing that gain must be exactly 1/5 to achieve perfect constancy with frequency. I confirmed this with some SPICE modeling.
There's no excess capacitance on the op-amp's summing junction, just two resistors, so no feedback capacitor is necessary.
ks like a Wien bridge with incorrect gain-setting resistor values.
er different circuit - with two op amps - to do the job. My clever friend i n Edinburgh has a one op amp circuit that does the 360 degree phase shift, at constant amplitude, but the output amplitude is a constant at roughly on e third of the input.
six months ago, but there's no trace of it in my e-mail files, though the r elevant Spice models are dated around the 20th June 2015.
put it in as an anti-piracy device ...
Good catch. However, see this 2nd order all pass:
formatting link
ring
which I saw in basic form in one of Analog Devices' books on Analog Design (chapter 8, active filters, appendix).
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