Trust your what-hour err watt hour meter

So, a '555 mounted in an earring, or (for oldsters) on a tie clip, would be appropriate.

Six times higher? Try this:

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.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

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. .

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

And stupidly.

The electric meters, with a convenient unlimited source of power, run as a mesh network eventually reaching a node up in their space atop a pole. Look for two broomsticks.

The node uses cellular data to report upstream, unless it's a dead spot when they have POTS.

The gas meters, relying on a lithium battery, use the lowest transmit power by talking to the nearest electric meter.....

^H^H^H^H^H Error Error

No, the gas meters do NOT use the electric mesh; they have to separately talk directly to the pole node....

And by the way, if you are in the mountains w/ no cell coverage, PG&E drives a car up with a mobile interrogator..

^H^H^H^H^H Error Error

....drives a car up, parks, and the reader walks to each meter to read by hand.

I was dumbfounded when their employee told me this...

--
A host is a host from coast to coast.................wb8foz@nrk.com 
& no one will talk to a host that's close.......................... 
Unless the host (that isn't close).........................pob 1433 
is busy, hung or dead....................................20915-1433

But the issue at hand is all about non-sinusoidal waveforms, is it not? Does C12 even cover such? It's only recently that such have predominated in resi loads.

[A friend got dragged into mess at a cement plant. His gadget depended on zero crossing detection. There was a mixer with a VFD; said mixer was a several thousand horsepower motor. At some speeds, it took such big chunks out of the plant feed that "zero" was not where it should be....]

--
A host is a host from coast to coast.................wb8foz@nrk.com 
& no one will talk to a host that's close.......................... 
Unless the host (that isn't close).........................pob 1433 
is busy, hung or dead....................................20915-1433

so what waveform will make them read LOW?

Not exactly unlimited, in many countries there is a limit to the power cons umption of an electricity meter. In Europe, something like 5 Watt/phase, bu t some brands require only 1 Watt/phase. B.t.w. this consumption is general ly not metered. You have to pay it anyway through your infrastructure charg es.

BR, Wim

To reduce costs and assuming a more or less resistive load, domestic electricity meters only measure 'active energy', the part where current and voltage are in phase. For industrial customers, like your cement mill, the reactive 'energy' is measured and billed separately.

BR, Wim Yes, I know reactive is not energy but still burdens the network.

There must be some box load that net slows down a disk meter.

Most meters are AC-coupled for the current measurement, and CTs may saturate with DC, too.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

I was part of Iris System Ltd in Winnipeg with an AMR system in mid 90's wi th 2 way ISM wireless using optical rotation sensor on mechanical meters. It worked well but company ran dry on R&D funds to make a custom embedded m icro chip with 2way Wireless radio in ISM band. They sold the IP to Itron w ith all the equipment, who is one of the biggest in the biz.

I think the postal service reads meters in some places here a receiver on their cars read them as they drive around delivering mail.

I don't know if it still exist but there also used to be a tracking device for bicycles and such. tiny super low power rf transceiver hidden on the bike, every time a postal van is in range a gps coordinate stored in a database so you could lookup it up if it went "missing"

It wouldn't take a lot of power to jam a bunch of DC amps into a circuit. That would have interesting effects on most any disk or electronic meter.

I'm sure it's being done. Meters may have tamper detection.

I designed one meter for use in India, where some serious fraction of the power is stolen... sort of like New York City. It had some anti-theft hooks. Sadly, it never saw production.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics