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| Subject | Re: Trust your what-hour err watt hour meter |
|---|---|
| Newsgroups | sci.electronics.design |
| References | (5 earlier) <nuvrbctetboer5nis9vcaseqd5uqkpsb69@4ax.com> <swnvA.17150$I%4.3087@fx10.iad> <cu1sbc1ibqftcmqc3h7k0gesb6gtrqao3k@4ax.com> <ZDCvA.7400$QP1.5791@fx27.iad> <ubvtbc5ak39bcql58gaum2dhl9sqnaaa8c@4ax.com> |
| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
| Date | 2017-03-07 14:21 -0500 |
| Message-ID | <pLmdnQ6G6pKxlSLFnZ2dnUU7-RPNnZ2d@supernews.com> (permalink) |
On 03/07/2017 01:43 PM, John Larkin wrote: > On Tue, 7 Mar 2017 13:05:44 -0500, bitrex > <bitrex@de.lete.earthlink.net> wrote: > >> On 03/06/2017 08:08 PM, John Larkin wrote: >>> On Mon, 6 Mar 2017 19:53:44 -0500, bitrex >>> <bitrex@de.lete.earthlink.net> wrote: >>> >>>> On 03/06/2017 07:35 PM, John Larkin wrote: >>>>> On Mon, 6 Mar 2017 18:20:38 -0500, bitrex >>>>> <bitrex@de.lete.earthlink.net> wrote: >>>>> >>>>>> On 03/06/2017 05:21 PM, John Larkin wrote: >>>>>>> On Mon, 6 Mar 2017 14:10:19 -0500, bitrex >>>>>>> <bitrex@de.lete.earthlink.net> wrote: >>>>>>> >>>>>>>> On 03/06/2017 01:29 PM, John Larkin wrote: >>>>>>>>> On Mon, 6 Mar 2017 17:25:05 +0000 (UTC), David Lesher >>>>>>>>> <wb8foz@panix.com> wrote: >>>>>>>>> >>>>>>>>>> <https://www.utwente.nl/en/news/!/2017/3/313543/electronic-energy-meters-false-readings-almost-six-times-higher-than-actual-energy-consumption> >>>>>>>>>> >>>>>>>>>> ....."The inaccurate readings are attributed to the energy meter's >>>>>>>>>> design, together with the increasing use of modern (often >>>>>>>>>> energy-efficient) switching devices. Here, the electricity being >>>>>>>>>> consumed no longer has a perfect waveform, instead it acquires >>>>>>>>>> an erratic pattern. The designers of modern energy meters >>>>>>>>>> have not made sufficient allowance for switching devices of >>>>>>>>>> this kind. When they dismantled the energy meters tested, the >>>>>>>>>> researchers found that the ones associated with excessively high >>>>>>>>>> readings contained a 'Rogowski Coil' while those associated with >>>>>>>>>> excessively low readings contained a 'Hall Sensor'." >>>>>>>>> >>>>>>>>> Neither is really associated with measurement error. The downstream >>>>>>>>> signal processing is. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> I smell lawsuits since the PoCo's have been removing the >>>>>>>>>> old meters en mass.... >>>>>>>>> >>>>>>>>> It's not hard to make a meter that measures and integrates true power >>>>>>>>> correctly. You can even buy chips that do all the hard work for you. >>>>>>>> >>>>>>>> 555 timer. >>>>>>>> >>>>>>>> The "Design an accurate true power meter with a 555" challenge! >>>>>>>> >>>>>>> >>>>>>> Can I use a few opamps too? >>>>>>> >>>>>>> A 555 could be used in a duty-cycle based multiplier. D.C. multipliers >>>>>>> were popular for precision multiplies and divides and square roots >>>>>>> once. >>>>>>> >>>>>>> >>>>>> >>>>>> The LM324 or the '741, your choice! ;-) >>>>> >>>>> uA709? >>>>> >>>>> >>>> >>>> Probably allowed, IIRC it's older but better spec-ed than either, just >>>> not internally compensated and not unity-gain stable without a bunch of >>>> external parts... >>> >>> It made a decent comparator, uncompensated. But the NPN diff pair >>> would zener, and it liked to latch up. >>> >> >> The input stage isn't like anything I've seen before (i.e. modern) - two >> Darlington followers on either side of load resistors in the collectors >> of the LTP, fed by a constant voltage source. >> >> IIRC all op-amps that have resistive loads tied to the positive supply >> instead of current-mirror loads are prone to latch-up, for a technical >> reason that escapes me at the moment. >> >> Why they do it like that? Something about monolithic small-signal PNPs >> with good enough specs not being possible to lay down with the >> fabrication process available in '67 or something? > > There's one PNP in the 709. Probably not a very good one. The slew > rate is glacial, 0.25 volts per us. > > There were some all-NPN opamps back then that were really awful. > > At some point I decided to start using 741s, which was a > million-dollar decision at the time. But prices dropped fast. > > Until the mid to late '80s the only PNPs you could get on linear processes were laterals. Laterals have low beta and are super super slow, but have some interesting features such as resisting reverse V_BE out to 20V or something like that, vs. ~6V for a normal planar device. To get speed out of those you had to restrict them to level shifting and use capacitive coupling around them. There was a trick for speeding up LM301s and LM318s by capacitive coupling into the offset adjust or frequency compensation pins. It worked OK but made the frequency compensation squirrelly, iirc. The first complementary bipolar process I encountered was National's VIP 1 (Vertically Integrated PNP), which produced some nice parts, especially the LM6361, which was fast and handled capacitive loads very well. (It's been discontinued but the LM8621 is similar.) See e.g. <http://www.ti.com/lit/pdf/snoa843>. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
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Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-06 17:25 +0000
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 10:29 -0800
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 14:10 -0500
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 14:21 -0800
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 18:20 -0500
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 16:35 -0800
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 19:53 -0500
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 17:08 -0800
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-07 13:05 -0500
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-07 10:43 -0800
Re: Trust your what-hour err watt hour meter Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-07 14:21 -0500
Re: Trust your what-hour err watt hour meter whit3rd <whit3rd@gmail.com> - 2017-03-06 18:36 -0800
Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 14:52 -0500
Re: Trust your what-hour err watt hour meter George Herold <gherold@teachspin.com> - 2017-03-06 12:04 -0800
Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 15:15 -0500
Re: Trust your what-hour err watt hour meter Jon Elson <jmelson@wustl.edu> - 2017-03-06 14:28 -0600
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 16:41 -0800
Re: Trust your what-hour err watt hour meter Jon Elson <jmelson@wustl.edu> - 2017-03-06 14:26 -0600
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 15:30 -0500
Re: Trust your what-hour err watt hour meter bitrex <bitrex@de.lete.earthlink.net> - 2017-03-06 15:28 -0500
Re: Trust your what-hour err watt hour meter rickman <gnuarm@gmail.com> - 2017-03-06 16:04 -0500
Re: Trust your what-hour err watt hour meter Jeff Liebermann <jeffl@cruzio.com> - 2017-03-06 16:22 -0800
Re: Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-09 16:03 +0000
Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:39 -0800
Re: Trust your what-hour err watt hour meter Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-09 15:46 -0800
Re: Trust your what-hour err watt hour meter TTman <pcw1.cad@ntlworld.com> - 2017-03-06 21:48 +0000
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-06 14:32 -0800
Re: Trust your what-hour err watt hour meter David Lesher <wb8foz@panix.com> - 2017-03-09 16:30 +0000
Re: Trust your what-hour err watt hour meter makolber@yahoo.com - 2017-03-09 12:27 -0800
Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-09 15:43 -0500
Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:49 -0800
Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-11 11:11 -0500
Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-11 12:28 -0800
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-09 12:59 -0800
Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-11 17:38 -0500
Re: Trust your what-hour err watt hour meter John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-11 15:04 -0800
Re: Trust your what-hour err watt hour meter Wim Ton <wim.ton@gmail.com> - 2017-03-09 12:47 -0800
Re: Trust your what-hour err watt hour meter Neon John <no@never.com> - 2017-03-08 20:05 -0500
Re: Trust your what-hour err watt hour meter Phil Allison <pallison49@gmail.com> - 2017-03-11 17:42 -0800
Re: Trust your what-hour err watt hour meter Phil Allison <pallison49@gmail.com> - 2017-03-06 17:53 -0800
Re: Trust your what-hour err watt hour meter Cursitor Doom <curd@notformail.com> - 2017-03-07 17:58 +0000
Re: Trust your what-hour err watt hour meter Anthony Stewart <tony.sunnysky@gmail.com> - 2017-03-09 15:31 -0800
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