Electronics Design does it Again!
in [Design]
|
Prev: Which type of volatile RAM has the least duration of data remanence when power-offed?
Next: USB3.0 FD Design
From: Michael A. Terrell on 13 May 2010 19:22 John Larkin wrote: > > Some places, like tony parts of Long Island, don't allow any vehicle > to be parked on the street. That's to keep the riff-raff out of posh > neighborhoods and off "our" beaches and parks. Some even forbid > parking a vehicle in sight on your own property. > > In theory a car can't be parked here in the same place for more than > 72 hours, but that's not much enforced. The weekly street cleaning > pretty much takes care of that. I guess Pease shuffles his rusty VWs > occasionally. That, or they've read his column and declared him dangerous & insane. ;-) -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: Jim Thompson on 13 May 2010 19:32 On Thu, 13 May 2010 13:52:17 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 13 May 2010 11:56:44 -0500, John O'Flaherty ><quiasmox(a)yeeha.com> wrote: > >>On Thu, 13 May 2010 09:45:57 -0700, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Thu, 13 May 2010 11:02:58 -0500, John O'Flaherty >>><quiasmox(a)yeeha.com> wrote: >>> >>>>I see attenuation of 1/2 at the input, gain of 4 (3+1), and >>>>attenuation of 1/2 at the output. LTSpice agrees, unless I made a >>>>mistake. >>> >>> >>>You did. You left out the pot and the cap. >> >>That wasn't a mistake, it was a choice. I believe the intention of the >>circuit is to have that as an AC ground, that is, as an adjustable >>reference voltage. Is the fact that the capacitor size wasn't >>specified in the published circuit the mistake that you meant to point >>out? > >My point was that the gain and the frequency response change as the >offset pot is turned. Tacky. Absolutely wrong. It's remarkably stable! Surprised even me... I expected some corner movement... the Thevenin equivalent of the pot ranges between zero and 250 Ohms. I invite everyone to Spice it. John "Always Wrong" Larkin is totally wrong AGAIN! [snip] ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | The only thing bipartisan in this country is hypocrisy
From: John Larkin on 13 May 2010 20:48 On Thu, 13 May 2010 09:23:56 -0700, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >news:6r5ou5lcgjqv2cg8vbg1831506uqtmod4g(a)4ax.com... >> Such brilliance! How do they keep doing it? > >A lot of graduating BSEEs today never really got that whole thing about >superposition, I suspect? :-) > >Hmm... there might be a good interview question in there somewhere... "It's >clear you can use an op-amp to sum an arbitrary number of inputs -- both with >positive and negative gains -- but why is it that the vast majority of the >time in an 'application example' you see people suggest only the inverting >form?" > >Although I think it was Jim or someone who mentioned that these days some >people don't even get past, "What's the approximate Vbe of any unremarkable >transistor at reasonable currents?" :-) I like this as a test: +10V | | | | c +5V--------------b e | | 1K | | | | gnd What's the base voltage? What's the base current? What's the emitter voltage? What's the collector current? What's the collector voltage? Any other comments? I'm not kidding. One "experienced ee" said that, since the transistor is saturated, the collector voltage is zero. A tech applicant said that the base voltage is 0.6. Some people got it right, but nobody has mentioned oscillation so far. John
From: Jim Thompson on 13 May 2010 21:06 On Thu, 13 May 2010 17:48:41 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 13 May 2010 09:23:56 -0700, "Joel Koltner" ><zapwireDASHgroups(a)yahoo.com> wrote: > >>"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >>news:6r5ou5lcgjqv2cg8vbg1831506uqtmod4g(a)4ax.com... >>> Such brilliance! How do they keep doing it? >> >>A lot of graduating BSEEs today never really got that whole thing about >>superposition, I suspect? :-) >> >>Hmm... there might be a good interview question in there somewhere... "It's >>clear you can use an op-amp to sum an arbitrary number of inputs -- both with >>positive and negative gains -- but why is it that the vast majority of the >>time in an 'application example' you see people suggest only the inverting >>form?" >> >>Although I think it was Jim or someone who mentioned that these days some >>people don't even get past, "What's the approximate Vbe of any unremarkable >>transistor at reasonable currents?" :-) > > >I like this as a test: > > > > +10V > | > | > | > | > c > +5V--------------b > e > | > | > 1K > | > | > | > | > gnd > > >What's the base voltage? > >What's the base current? > >What's the emitter voltage? > >What's the collector current? > >What's the collector voltage? > >Any other comments? > > >I'm not kidding. One "experienced ee" said that, since the transistor >is saturated, the collector voltage is zero. A tech applicant said >that the base voltage is 0.6. > >Some people got it right, but nobody has mentioned oscillation so far. > >John When cornered, change the subject ?:-) How about the Pease/Matlin level shifter? Please elaborate on your statement, "My point was that the gain and the frequency response change as the offset pot is turned. Tacky." ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | The only thing bipartisan in this country is hypocrisy
From: JosephKK on 14 May 2010 02:19
On Thu, 13 May 2010 08:19:22 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > > >http://electronicdesign.com/article/power/non_inverting_level_shifter_requires_only_one_op_amp_one_supply_voltage.aspx > > >Such brilliance! How do they keep doing it? > >Sarcasm aside, he made a mistake. > >And we should take up a collection and buy Pease some grid paper. > >John The site violates my no unauthorized cookies policy. |