> On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
> <mike.terr...@earthlink.net> wrote:
> >micky wrote:
> >> Really older blankets might have a problem with low frequency
> >> radiation.
> > Very doubtful, considering that one cycle is 5000000 meters long.
> >That's 5,000 Kilometers or about 3106 miles. How big is that blanket?
> Are you saying unless something is 3000 miles long, it can't radiate
> low frequency?.
No, but has to be an appreciable fraction of a wavelength, or we
would be forced to use DC power for everything.
> I don't think so. And if that were the case, then a
> radio transmitter broadcasting at 600 KHz would require an antenna
> that was a third of a mile long.
No, it doesn't. AM BC band broadcast antennas are not a full
wavelength, and the aren't resonant at the transmit frequency. They all
use use L/C networks to make the tower work at the allocated frequency. Some ATU are as large as the AM transmitter when the tower is difficult
to configure. It gets even worse with multiple tower arrays, and
different day/night patterns and transmit power authorizations. You
should have seen the ATUs at the VOA station in Bethany, Ohio. They
could put up to 500,000 watts of RF at any frequency from 2 to 30 MHz. They had multiple antennas, and more than one a 50,000 transmitter was
switched to full power before the antenna was properly tuned, and wet
the wood support poles on fire.
I was a broadcast engineer at a number of radio & TV stations over the
decades.
> The question is not whether it can radiate, but whether the low
> frequency is harmful.
> This was the controversy that also centered
> around power lines, often just past the backyard of people's homes.
Very long power lines can radiate. That's wy there are regional
power grids across the US, and they are interconnected with HV DC.
> But you do remind me that most of the opinion, or maybe the consensus
> after a few years, was that that was not harmful. By then electric
> blankets had already been redesigned, since they were much easier to
> redesign than power lines. But yes, they're no longer thought to
> be a risk, I think. I'd forgotten.
I think we are feeding a troll (original poster), but yes, it is stupid to boost a voltage or go from AC to DC for a resistive heater. A company that I will not embarrass (plus I forget the name) was using a DC/DC for a heated stethoscope. [Hey Doc, do you keep that thing in the 'fridge?] Far better to get a heating element of the right resistance. And from what I hear, it is the speculum that needs heating.
BTW, I've been to the Jack Daniels factory. It is worth the tour. The irony is the factory is located in a "dry" county, so you can't do any tasting there. [See what happens when you let Bible thumpers get too much power!] The factory is more like a college campus. Lots of buildings surrounded by patches of green grass. The whiskey is aged in a manner like you store explosives. The "bunkers" are away from the factory and have a buffer zone so that all the stock won't be destroyed should one site catch fire.
>> On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
>> <mike.terr...@earthlink.net> wrote:
>> >micky wrote:
>> >> Really older blankets might have a problem with low frequency
>> >> radiation.
>> > Very doubtful, considering that one cycle is 5000000 meters long.
>> >That's 5,000 Kilometers or about 3106 miles. How big is that blanket?
>> Are you saying unless something is 3000 miles long, it can't radiate
>> low frequency?.
> No, but has to be an appreciable fraction of a wavelength, or we
> would be forced to use DC power for everything.
>> I don't think so. And if that were the case, then a
>> radio transmitter broadcasting at 600 KHz would require an antenna
>> that was a third of a mile long.
> No, it doesn't. AM BC band broadcast antennas are not a full
> wavelength, and the aren't resonant at the transmit frequency. They all
> use use L/C networks to make the tower work at the allocated frequency.
> Some ATU are as large as the AM transmitter when the tower is difficult
> to configure. It gets even worse with multiple tower arrays, and
> different day/night patterns and transmit power authorizations. You
> should have seen the ATUs at the VOA station in Bethany, Ohio. They
> could put up to 500,000 watts of RF at any frequency from 2 to 30 MHz.
> They had multiple antennas, and more than one a 50,000 transmitter was
> switched to full power before the antenna was properly tuned, and wet
> the wood support poles on fire.
> I was a broadcast engineer at a number of radio & TV stations over the
> decades.
>> The question is not whether it can radiate, but whether the low
>> frequency is harmful.
>> This was the controversy that also centered
>> around power lines, often just past the backyard of people's homes.
> Very long power lines can radiate. That's wy there are regional
> power grids across the US, and they are interconnected with HV DC.
>> But you do remind me that most of the opinion, or maybe the consensus
>> after a few years, was that that was not harmful. By then electric
>> blankets had already been redesigned, since they were much easier to
>> redesign than power lines. But yes, they're no longer thought to
>> be a risk, I think. I'd forgotten.
Got to know the transmitter engineers at NSS Annapolis. 24 kHz at 1 million watts. The ATU was in a building four stories tall.
A friend of mine and I were instrumental in saving the three 600 foot self supporting towers on Greenbury Point at the Navy Academy property. The array was called a modified Goliath Array. The main feed went to a central 1200 foot hot tower fed with four inch diameter litz cable. Six towers around the central tower were 800 feet tall and made up a capacitance hat. The hat was extended to the east to the three 600 foot towers.
Two water cooled Eimac tubes made the power. They were amazingly small, maybe a foot tall. Cooled with deionized water in the anodes. A third tube was between the two that could be switched in if one of the main tubes failed.
It was really sad to see the site decommissioned. A little bit of our history died.
>I think we are feeding a troll (original poster), but yes, it is stupid to >boost a voltage or go from AC to DC for a resistive heater. A company that >I will not embarrass (plus I forget the name) was using a DC/DC for a >heated stethoscope. [Hey Doc, do you keep that thing in the 'fridge?] Far >better to get a heating element of the right resistance. And from what I >hear, it is the speculum that needs heating.
> BTW, I've been to the Jack Daniels factory. It is worth the tour. The > irony is the factory is located in a "dry" county, so you can't do any > tasting there. [See what happens when you let Bible thumpers get too much > power!] The factory is more like a college campus. Lots of buildings > surrounded by patches of green grass. The whiskey is aged in a manner like > you store explosives. The "bunkers" are away from the factory and have a > buffer zone so that all the stock won't be destroyed should one site catch > fire.
You fucking nitwit. That rule was made by a consensus of the local community. It has no effect on you other than you couldn't get a free handout of booze. Typical libtard. Maybe you can ask obozo for free whiskey.
> >> On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
> >> <mike.terr...@earthlink.net> wrote:
> >> >micky wrote:
> >> >> Really older blankets might have a problem with low frequency
> >> >> radiation.
> >> > Very doubtful, considering that one cycle is 5000000 meters long.
> >> >That's 5,000 Kilometers or about 3106 miles. How big is that blanket?
> >> Are you saying unless something is 3000 miles long, it can't radiate
> >> low frequency?.
> > No, but has to be an appreciable fraction of a wavelength, or we
> > would be forced to use DC power for everything.
> >> I don't think so. And if that were the case, then a
> >> radio transmitter broadcasting at 600 KHz would require an antenna
> >> that was a third of a mile long.
> > No, it doesn't. AM BC band broadcast antennas are not a full
> > wavelength, and the aren't resonant at the transmit frequency. They all
> > use use L/C networks to make the tower work at the allocated frequency.
> > Some ATU are as large as the AM transmitter when the tower is difficult
> > to configure. It gets even worse with multiple tower arrays, and
> > different day/night patterns and transmit power authorizations. You
> > should have seen the ATUs at the VOA station in Bethany, Ohio. They
> > could put up to 500,000 watts of RF at any frequency from 2 to 30 MHz.
> > They had multiple antennas, and more than one a 50,000 transmitter was
> > switched to full power before the antenna was properly tuned, and wet
> > the wood support poles on fire.
> > I was a broadcast engineer at a number of radio & TV stations over the
> > decades.
> >> The question is not whether it can radiate, but whether the low
> >> frequency is harmful.
> >> This was the controversy that also centered
> >> around power lines, often just past the backyard of people's homes.
> > Very long power lines can radiate. That's wy there are regional
> > power grids across the US, and they are interconnected with HV DC.
> >> But you do remind me that most of the opinion, or maybe the consensus
> >> after a few years, was that that was not harmful. By then electric
> >> blankets had already been redesigned, since they were much easier to
> >> redesign than power lines. But yes, they're no longer thought to
> >> be a risk, I think. I'd forgotten.
> Got to know the transmitter engineers at NSS Annapolis. 24 kHz at 1 million
> watts. The ATU was in a building four stories tall.
> A friend of mine and I were instrumental in saving the three 600 foot self
> supporting towers on Greenbury Point at the Navy Academy property. The array
> was called a modified Goliath Array. The main feed went to a central 1200
> foot hot tower fed with four inch diameter litz cable. Six towers around the
> central tower were 800 feet tall and made up a capacitance hat. The hat was
> extended to the east to the three 600 foot towers.
> Two water cooled Eimac tubes made the power. They were amazingly small,
> maybe a foot tall. Cooled with deionized water in the anodes. A third tube
> was between the two that could be switched in if one of the main tubes
> failed.
> It was really sad to see the site decommissioned. A little bit of our
> history died.
That Bethany VOA site is now a stinking golf course.
>> So ahm happier'n'a alcoholic workin the night shift in a Jack Daniels
>> distillery.... with my 400# deep cycle battery, 1500 W inverter (sitting
>> in the back seat of m'truck), and my brand new blue electric
>> blankey-poo.....
>> Now I can curl up in a fetal position -- in m'truck -- in compleat toasty
>> comfort.....
>> Now, don't ax me WHY I gotta curl up in a fetal position -- in m'truck.
>> Just suffice it to say, if you had my yob, you'd be curling up in a fetal
>> position in YOUR truck, too.
>> Except for one thing.....
>> My g-d electric blankeypoo dudn't WORK with my 1500 W fukn inverter!!!!!
>> WTF??????
>> And the reason quickly became clear: some electronics don't work with
>> modified (read: shit) sine wave power.
>> But, what electronics are in a g-d electric blanket???
>> So I take apart the three-heat controller, and lo and behold, the goddamm
>> thing looks like the motherboard of a small PC.... holy shit.... for a
>> $25 blankeypoo????
>> Tryna sleuth out the ""circuitry"" of this electric blanket reminds me of
>> the two days I spent tryna fix a $2.00 flashlight.... unsuccessfully....
>> holy shit....
>> The blanket has three wires between it and the controller, but only two of
>> the wires register continuity!! From which I surmised, via advanced Ohm's
>> Law, that there is only one element in the blanket, and the controller
>> actually does control voltage/current, ie, no switching among elements, cuz,
>> well, there's only one element.
>> .
>> AND, the resistance is in fact the "right" resistance, cuz the wattage is 60
>> W (1/2 amp), and the ohms measure 230.
>> So now I got an extree wire that I don't know wtf it does, amidst my awe of
>> all this goddamm gratuitous complexity.
>> Now, I do have an inkling surrounding this latest Conspiracy of Gratuitous
>> Complexity -- whose fundamental purpose is, of course, to assfuck the entire
>> Global Population up to their collective ileocecal valves, so that Orwell
>> looks like summer fukn camp.
>> It appears that this particular example (this blue electric blanket) of
>> Gratuitous Complexity has to do with.....<shudder> <shudder> SAFETY!!!!!
>> And of course the li'l CHILDREN.......
>> Btw, a brief digression:
>> You DO know that they now make crawling helmets for toddlers??? Yes
>> indeedy, google helmets for babies crawling , and pick your link.
>> Better yet, ORDER yours, right away, so's when you take the li'l future Wall
>> Street predator-to-be to Montessori for his (first) pre-school interview,
>> you'll be showing up correck.
>> You yourself and the spouse should also wear matching bicycle helmets, as
>> well, just to show Montessori that the whole Beaver family is indeed
>> correck.....
>> Back to this g-d blanket bidniss....
>> This shit blanket, for safety (it is UL listed btw), SHUTS OFF
>> automatically EVERY GODDAMM HOUR!!!!WTF?????
>> I mean, look, the g-d blanket is a *whole 60 effingW*!!!! My goddamm BODY
>> puts out more heat than that....
>> fyi, Your BMR of about 1 cal/min is actually nearly exactly 70 W of heat....
>> which is why 10 blustering assholes in a meeting room make the place so
>> goddamm hot.
>> So some dumb QA engineering fuckhead sed, Oh, OH, 60 W -- spread over **24
>> sq ft of g-d blanket**, no less -- is MUCH too dangerous!!!!
>> Sheeit, in that case, my 70 W of body heat puts me at risk for
>> self-immolation, right???
>> Fuuuuuuuck, they couldn't have timed it for 8 hours?? 6 hours???? 4
>> hours????? WTF???????
>> So now, some while after the blanket shuts off, I'll freeze my goddamm ass
>> off, have furtive nightmares, wake up, and flail around for the controller,
>> just to reset it.
>> So now I can't even g-d SLEEP worth a goddamm, in my fetal position -- and
>> if you knew how long it takes me to get in that fetal position (in m'truck),
>> you'd realize this is really a significant issue.
>> OK.... so NOW ahm gettin it:
>> SAFETY, and our precious li'l bratty g-d CHILDREN, require a solidstate
>> automatic safety controller. Shitty li'l dropping resistors, or a xsformer,
>> or split heating elements, just won't do it anymore.
>> Now, they got a g-d controller in a $25 electric blanket that could have
>> gotten Neil Armstrong to the g-d moon.
>> Well, let me tell you, no one, but NO ONE messes with Angst's fetal
>> position/sleep....
>> So I took that controller off (via the detachable connector) and
>> hard-wire-crimped a shit 18 ga wire with a shit 99c-store two-in-a-pack
>> unpolarized plug, so now's I got *60 uninterrupted W* of blazing power,
>> blasting thru my li'l blue blankeypoo. What a fukn triumph.....
>> My gripe against Gratuitous Complexity harks back to my erstwhile 1971
>> Datsun 510, which got better gas mileage than almost every effing car out
>> here today, ceptin Volts'n'Prius'n'shit, and mebbe that VW TDI motor....
>> AND, I could fix it my goddamm self.
>> And I think I drove around Hawaii about 25 g-d times in a Datsun B-210, on a
>> gallon of gas.
>> Now, cars are so fukn complicated.....
>> HOW COMPLICATED ARE THEY???????
>> Cars are so fukn complicated, that factory Toyoter mechanics make more money
>> than asshole college puhfessuhs..... AS THEY RIGHTLY SHOULD, cuz college
>> professors are just absolutely fukn useless. goodgawd..... What a sham
>> the college credit is, and a bankrupting sham at that.
>> Cars now weigh 50% more than in the 70s.... and you can't even adjust the
>> g-d IDLE!!!!
>> Well, you can, I spose, with a laptop and about $1,000 worth of g-d
>> programming.....
>> Part of the Conspiracy behind Gratuitous Complexity is, imo, the desire to
>> shut out the small entreepreeneer, bidnissman. A good fraction of the
>> people on these ng's could *make their own perfectly navigable electric
>> car*, with a welder, lathe, milling machine, some fukn batteries and a
>> motor. Or mebbe just a welder, drill press, and an angle grinder....
>> But fukn Chevrolet and Nisan barely got *their* electric cars out, the
>> regulatory ante is so goddamm high. Near $40K for a g-d electric motor and
>> a bunch of g-d batteries....
>> So, inyway, Angst finally has his new blue blankeypoo blazing away, and I'll
>> be fellatingly positioning myself in peaceful bliss tonite, in m'truck, with
>> my 400# marine battery/1500W inverter right behind my blissful head.
>> Oh shit, did I say "fellatingly"??? That would be "fetally", "fetally
>> positioning myself in peaceful bliss".....
>Our old electric blanket died several years ago. It had the bimetalic >strip type control with the 0-10 dial. We loved it because we could turn >it on an hour before going to bed and the bed would be toasty warm when >we went to bed.
>It died and we got a new one and it would not preheat the bed. We >returned it to the manufacturer and they said it was working fine, but >sent a new blanked anyway. New worked the same way.
>I am convinced the thing knows when there is a body in the bed and when >there is not. It can be on for hours and the bed is still cold when we >go to bed. About 1/2 hour later, the blanket is warm, but we freeze >until then. Real POS design.
>Paul
I was told that that last is indeed true. Something about internal
sensing of warmth. They now use carbon fiber strands to heat rather
than wires. I had one actually start burning over my feet, which woke
me up rather suddenly. And I had to put out the burning fur of one fo
the dogs who evidently had shorted out the wiring in his sleep. It was
a close thing. The replacement wouldnt get warm..preheat at all and
only would warm up like yours..after we were in bed. When I called the
manufacture..they gave me info (pre stroke) on how it works..and I
cant remember the details..but yeah...most of them dont preheat
anymore.
Gunner
--
""The Democratic constituency is just like a herd of cows. All you have
to do is lay out enough silage and they come running. That’s why I
became an operative working with Democrats. With Democrats all you
have to do is make a lot of noise, lay out the hay, and be ready to
use the ole cattle prod in case a few want to bolt the herd.
Eighty percent of the people who call themselves Democrats don’t have
a clue as to political reality.
What amazes me is that you could take a group of people who are hard
workers and convince them that they should support social programs
that were the exact opposite of their own personal convictions. Put a
little fear here and there and you can get people to vote any way you
want.
The voter is basically dumb and lazy. The reason I became a Democratic
operative instead of a Republican was because there were more
Democrats that didn’t have a clue than there were Republicans."
James Carvell, DNC operative
>>> Such circuits typically prevent current from flowing at all within a
>>> half cycle, until a point is reached where the remainder of the half
>>> cycle would deliver an amount of energy that would, if delivered over
>>> the entire half cycle, represent the desired power. Once triggered, the
>>> triac conducts until current drops below some smallish threshold.
>>> A circuit designed to do that with a sine-wave is going to be somewhat
>>> thrown by an input that is a modified sine-wave.
>>I'm fully aware of how SCR and Triac (or generically, Thyristor)
>>"dimmers" function, and how to build them (from scratch, without any
>>supplied schematic).
>>I'm also aware that a "modified sine wave" or "simulated sine wave" would
>>satisfy the needs of most of that type of circuit, with the exception
>>that the initial triggering and the the subsequent "near zero"-crossing
>>cutoff might occur late and early, respectively, from where they ought.
>>Such circuits don't work nicely on square waves, primarily because they
>>don't have time to properly turn off. There's usually some capacitance
>>in the gate circuit (sometimes driven by a diac) that prevents a very
>>rapid change from full voltage through zero to the opposite polarity
>>from lasting long enough below the quench voltage for the device to turn
>>off.
>>Such _can_ be the case with a simulated sine wave, where the voltage
>>might go from (say) +10V-0--10V on a square edge. But most inverter
>>companies realized a long (long) time ago that doing it that way causes
>>problems, so they switched (pun) to a waveform that stays at zero long
>>enough for such devices to turn off properly.
>>Only a really old, or really cheap Chinese inverter would not have that
>>feature. For all I know, he has both AND a cheap Chinese blanket that
>>didn't take into consideration the problems it might see on old Chinese
>>inverters.
>>But it's not the case that simulated sine wave inverters universally
>>cause problems with thyristor switches.
>>LLoyd
> What he NEEDS is a 12 volt blankie. My baby brother has been a long
> distance trucker across north america, from Alaska to Florida - and
> has 12 volt mattress warmer and 12 volt electric blanket for YEARS.
> Lost 'em both when he rolled the truck last year. Bust his neck too,
> but he's back on the road - doing mostly short haul flatland driving
> hauling crude - less than 2 years after the crash.
I considered the 12V route -- blankets, heaters, seat warmers, all available, couild use the same deep cycle batt.
But, I opted for 120 V stuff so I could use it inside the house as well as in the truck.
But, the 12 V option might be better for some stuff. We'll see how it goes.
I'm going to experiment with foiled-up 100 W light bulbs for heat, as well. Altho I also have a nice 9" Optimus parabolic heater, only 300 W -- don't yet know how to gauge wattage requirements of a small space that is exposed to the elements.
My hot-wired blanket now works, and as far as the risk of fire goes, even at full blast, it's got a long long way to go before ignition... heh, famous last words, eh?? LOL
-- EA
Products are designed to produce the best perceived value by the most
customers...mitigated by applicable safety regulations.
People who like to sleep in their truck are not the target demographic
and never will be.
If you expect to sleep "outside the box", you need to pick your
electric blankets more carefully. Ranting won't help.
Jamie <jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
> Vic Smith wrote:
> > On Fri, 9 Nov 2012 19:01:11 -0500, "Existential Angst"
> > <fit...@optonline.net> wrote:
> >>And the reason quickly became clear: some electronics don't work with
> >>modified (read: shit) sine wave power.
> > Well-known inverter - and cheap generator - gotcha.
> > I mentioned it in one of these "inverter" posts regarding furnace
> > control boards. Too bad you missed that.
> > Only way to avoid the gotcha is to pay up for pure sine wave.
> Or, just put a small transformer on the affected device.
...or buy another blanket that is better designed.
-- ~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
> When a device only turns on and off at the AC zero crossings, we call it > a "wire".
Oh, and yes -- I know about those controllers that do switch only at the zero-crossings, but then count cycles to accomplish duty cycle control.
Those are even more "gratuitously complex" than the others, but perhaps they've gotten that sort of control down into the $0.80USD range. That's about the price it would have to be to find its way into a consumer electric blanket.
>> When a device only turns on and off at the AC zero crossings, we call
> it
>> a "wire".
> Oh, and yes -- I know about those controllers that do switch only at the
> zero-crossings, but then count cycles to accomplish duty cycle control.
> Those are even more "gratuitously complex" than the others, but perhaps
> they've gotten that sort of control down into the $0.80USD range. That's
> about the price it would have to be to find its way into a consumer
> electric blanket.
> LLoyd
A cheap pic could easily do that. It used to be a bi-metallic thermo switch.
>...
> The small standby UPS does no wave shaping when allowing the load to
> run on "line " voltage - and most are, at best, modified sine wave
> output.
A UPS "modified sine wave" is a sequence of positive and negative square pulses at 160 to 170V, with enough off time between them to reduce the average (RMS?) voltage to 120V. I've seen the pulse width increase at higher loads that pulled down the peak voltage.
Some of them can run off large external batteries without overheating. Check the surplus stores for used ones. The downloadable manual shows the simple but not obvious way to remove the old batteries.
I just discovered that the sensor-logging feature of HWiNFO32 v4.06 freeware can record the run time of an unattended laptop on its battery, It captures the battery voltage, the power drain and the estimated percent of remaining capacity, which will show a sudden drop to empty if the battery's microcontroller IC needs to recalibrate itself with a full discharge cycle.
http://www.hwinfo.com/
I use recording TV and displaying Internet weather radar as representative high and moderate power applications to check UPS run time. During an outage I wouldn't let it run idle on precious battery power though that's the easiest measurement to make. The Event Log will capture shutdown time.
I haven't tried yet, but it should also show when the UPS or inverter powering the laptop plus your test load shuts off and the laptop switches to internal battery.
On Sat, 10 Nov 2012 02:48:29 -0500, "Existential Angst"
<fit...@optonline.net> wrote:
>My hot-wired blanket now works, and as far as the risk of fire goes, even at >full blast, it's got a long long way to go before ignition... heh, famous >last words, eh?? LOL
It sounds like you're on a parallel path to what I have in my
motorhome. It had 2 tired deep cycle batteries which I replaced and
added a third. If I remember right I have about 1kwh capacity to 50%.
I bought a 1000W true sine inverter on sale for $150. Now I have more
battery capacity for running the furnace heavily overnight when dry
camping in cold temperatures. And I don't have to use the generator
nearly so often. Even the inverter microwave is OK at half power.
In my rig the bedroom is at the back. It stays cool when the rest of
the coach is toasty. I've considered getting an electric blanket and
running it off the inverter and then turning down the furnace
thermostat overnight. I should break even on the battery use and come
out ahead on propane. One wrinkle is that the furnace has an outlet
into the holding tank compartment. If I run the furnace too little in
below freezing temperatures then I'd have to worry about the dump
valves freezing. I've traveled in the off season and my record so far
for being comfortable is 14 degrees Fahrenheit. Man the RV crowd
really thins out when it gets cold. :) If I get a chance to
experiment further I'll report here.
> > That Bethany VOA site is now a stinking golf course.
> It went the way of the American values it promoted.
It should have been turned into a museum. That site had a huge impact
on W.W. II It went from an empty pasture, to the most up to date Short
Wave Radio transmitter site in a very short period. It fed news & music
to the world, and was a huge boost to morale.
> My g-d electric blankeypoo dudn't WORK with my 1500 W fukn inverter!!!!!
> WTF??????
> And the reason quickly became clear: some electronics don't work with
> modified (read: shit) sine wave power.
> But, what electronics are in a g-d electric blanket???
I sometimes use a heating pad, for a heated seat. Many of those won't work with an inverter.
[snip]
-- 45 days until the winter celebration (Tue Dec 25, 2012 12:00:00 AM).
>>distance trucker across north america, from Alaska to Florida - and
>>has 12 volt mattress warmer and 12 volt electric blanket for YEARS.
>>Lost 'em both when he rolled the truck last year. Bust his neck too,
>>but he's back on the road - doing mostly short haul flatland driving
>>hauling crude - less than 2 years after the crash.
>Glad he's doing so well
Yea, he's only got less than 30 degrees total lateral movement, and
by the end od a day his neck is sore - but with convex mirrors on the
truck he's OK as long as he's carefull. Guess they figured it was
better to let him drive again than to try to retrain him for something
else.
Darn good driver. Other than being struck by lighning, a herd of
antelope, and about a hundred separate deer his record was very good
till he ditched and barrel rolled just west of Calgary 2 years ago May
24. Not sure how many million miles he and his little dog CB have
under thair belt - CB is 16 now and was on the road with him from the
time he was a pup antill about 6 months before the accident. (Jack
Russel /???? cross)
>>>"tm" <No_one_h...@white-house.gov> fired this volley in news:k7khim$at3$1
>>>@dont-email.me:
>>>> Well, if it has a poorly designed triac controller, it may radiate RFI.
>>>Even well-designed ones do on the turn-on. Only a lot of down-line
>>>choking and shielding will get it down to reasonable levels.
>>>But it's not likely that the RFI emitted from a 1/2-amp controller would
>>>emit enough to be harmful to tissue. Could screw up your pacemaker, I
>>>guess...
>>>Lloyd
>> There ARE controllers that switch on the downward slope of the sine,
>> greatly reducung theRFI.
>> One thing for sure - an electric blanket sure plays havok with
>> magnetometers, like in electronic compases - and electronic gyros.
>It's best when they switch on the zero crossings.
On Fri, 09 Nov 2012 21:46:08 -0800, miso <m...@sushi.com> wrote:
>I think we are feeding a troll (original poster), but yes, it is stupid >to boost a voltage or go from AC to DC for a resistive heater. A company >that I will not embarrass (plus I forget the name) was using a DC/DC for >a heated stethoscope. [Hey Doc, do you keep that thing in the 'fridge?] >Far better to get a heating element of the right resistance. And from >what I hear, it is the speculum that needs heating.
>BTW, I've been to the Jack Daniels factory. It is worth the tour. The >irony is the factory is located in a "dry" county, so you can't do any >tasting there. [See what happens when you let Bible thumpers get too >much power!] The factory is more like a college campus. Lots of >buildings surrounded by patches of green grass. The whiskey is aged in a >manner like you store explosives. The "bunkers" are away from the >factory and have a buffer zone so that all the stock won't be destroyed >should one site catch fire.
The county is now suggesting an increased tax, and Jack Daniels is
suggesting that it _can_ move and leave a bunch of unemployed :-)
...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 |
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I love to cook with wine. Sometimes I even put it in the food.
>So ahm happier'n'a alcoholic workin the night shift in a Jack Daniels >distillery.... with my 400# deep cycle battery, 1500 W inverter (sitting >in the back seat of m'truck), and my brand new blue electric >blankey-poo.....
>Now I can curl up in a fetal position -- in m'truck -- in compleat toasty >comfort.....
>Now, don't ax me WHY I gotta curl up in a fetal position -- in m'truck. >Just suffice it to say, if you had my yob, you'd be curling up in a fetal >position in YOUR truck, too.
<muratla...@gmail.com> wrote:
><cl...@snyder.on.ca> wrote in message >news:prdr98tujur9ofk02do25klmor59rupktc@4ax.com...
>>...
>> The small standby UPS does no wave shaping when allowing the load to
>> run on "line " voltage - and most are, at best, modified sine wave
>> output.
>A UPS "modified sine wave" is a sequence of positive and negative >square pulses at 160 to 170V, with enough off time between them to >reduce the average (RMS?) voltage to 120V. I've seen the pulse width >increase at higher loads that pulled down the peak voltage.
>Some of them can run off large external batteries without overheating. >Check the surplus stores for used ones. The downloadable manual shows >the simple but not obvious way to remove the old batteries.
That is not a "small standby UPS" by anyone's definition. It is an
online UPS - AKA dual conversion.
>I just discovered that the sensor-logging feature of HWiNFO32 v4.06 >freeware can record the run time of an unattended laptop on its >battery, It captures the battery voltage, the power drain and the >estimated percent of remaining capacity, which will show a sudden drop >to empty if the battery's microcontroller IC needs to recalibrate >itself with a full discharge cycle.
>http://www.hwinfo.com/
>I use recording TV and displaying Internet weather radar as >representative high and moderate power applications to check UPS run >time. During an outage I wouldn't let it run idle on precious battery >power though that's the easiest measurement to make. The Event Log >will capture shutdown time.
>I haven't tried yet, but it should also show when the UPS or inverter >powering the laptop plus your test load shuts off and the laptop >switches to internal battery.
>>> That Bethany VOA site is now a stinking golf course.
>> It went the way of the American values it promoted.
> It should have been turned into a museum. That site had a huge impact
> on W.W. II It went from an empty pasture, to the most up to date Short
> Wave Radio transmitter site in a very short period. It fed news & music
> to the world, and was a huge boost to morale.
Switched wires radiate as per &E/&t (Maxwell's Eqns).
It's called sparks, and can nearly radiate all over the
radio+ spectrum.
Ken
PS: Wife & daughter used electric sheets prior to bed time.
