AC line filtering
Thats is correct.... we have been living with RF all around us for a long time now.... it isnt an audio issue most of the time.
What you would benefit from is removing noise on the ac line which is in the audio frequency range.... and maybe up to the audio amp's BW.
THx-RNMarsh
- none creates any audio issues.
Even the HF stuff is ok, though it's not aimed at the house and I only run 100W PEP. The touch sensitive lamp the XYL has turns on when I power up on 40 metres though....
Thats is correct.... we have been living with RF all around us for a long time now.... it isnt an audio issue most of the time.
What you would benefit from is removing noise on the ac line which is in the audio frequency range.... and maybe up to the audio amp's BW.
THx-RNMarsh
yes it is and yes you can...... unless SMPS in TV (or anything) has a VERY different freq of operation than all others .... which they dont. Filtering a bandwidth of freq to cover the audio amp BW is all you need to do.
For example, this is what I have used.... 400Hz to 2MHz and over 100dB atten over most of that range [10MHz is still -50dB atten].
View attachment dual xfmr filter response.pdf
THx-RNMarsh
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In my experience, most of nasty audio related hash is done by around 85 kHz or so (obtiously including harmonics). Look it up on a scope and you will see a marked drop in level above 85 kHz or so. On the other hand, most line filters I have encountered start to do their thing at 600 kHz or so, when most of the hash has already gotten into the system. A case of too little, too late?
Although HF noise is nothing to joke about, I do feel it is sometimes overrated. After all, look at the power of what's producing them - located near you FM repeater will no doubt be a major issue, also a cell phone repeat station, but beside that - not much else.
And of course, whatever you do, you must not touch the 50-60 Hz range.
Do not confuse home automation with IoT. That is just one use case. For most of the others wifi is seriously sub-optimal. It's not particularly optimal for home automation either.
That is around the freq of most SMPS... esp used in new flat panel TV's. Note that commercial line filters are not designed for audio requirements.
But, as I already showed via spectrum analyzer photographs... everything from computers and CD/DVD players etc etc put out unwanted noise on the ac lines..... measured going beyond 85KHz, as shown. So, it depends on what you have running in your home that matters. Never-the-less, a broadband filter as I have shown will take care of it all for most everyone's environment.
[BTW... That shown filter response is one I designed and built.... not a commercial off-the-shelf product.]
THx-RNMarsh
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Completely agreed, Richard.
My own filter does -16 dB at 20 kHz, and -65 dB at 85 kHz, minimum guaranteed specs (which means that TYPICAL figures will be a bit better). And since the ferrite rings I use are made of sintered material, which tends to compress itself afre years of use, the irony is that measuring it again after say 3 years of daily use will yield actually better results (not significantly, by about 1-2 dB typically).
My own filter does -16 dB at 20 kHz, and -65 dB at 85 kHz, minimum guaranteed specs (which means that TYPICAL figures will be a bit better). And since the ferrite rings I use are made of sintered material, which tends to compress itself afre years of use, the irony is that measuring it again after say 3 years of daily use will yield actually better results (not significantly, by about 1-2 dB typically).
whither IoT
Does anyone know anyone who is positively excited about the IoT, other than chipmakers, or some ambitious crowdfunding folk?
It seems like the biggest bunch of drum-beating yet and for almost no benefit, and with plenty of risks.
Even multizone wireless audio seems like a colossal snore. How often do you want to have music in more than one room? It reminds me of the ancient proliferation of "background music". My late father did custom installations for a while for the rich and famous, and once had a customer ride with him in his elevator. He said George, what is missing? Of course he wanted music in the elevator.
Does anyone know anyone who is positively excited about the IoT, other than chipmakers, or some ambitious crowdfunding folk?
It seems like the biggest bunch of drum-beating yet and for almost no benefit, and with plenty of risks.
Even multizone wireless audio seems like a colossal snore. How often do you want to have music in more than one room? It reminds me of the ancient proliferation of "background music". My late father did custom installations for a while for the rich and famous, and once had a customer ride with him in his elevator. He said George, what is missing? Of course he wanted music in the elevator.
In industrial and enterprise space very. But its not the use cases trotted out by the media. It's leveraging disruptive technology to be able to do things that weren't cost effective in the past.
I certainly don't want my white goods on the internet. intranet maybe, but no further. Some cars already have 3 SIMs in them.
But I wouldn't worry. Everyone is fighting for a piece of pie in the home space at the moment without considering consumer benefits. The misled who think NEST is cool already have it, so that has fallen limp, to the point where Google have opensourced a lot of it. Apple are over a year late as they've suddenly realised its hard.
As I like saying 'told you so', I find it all fun
The IIoT I can countenance, provided that appropriate security measures are in place.
The home stuff was ridiculously oversold IMO. I read an article about the NEST guy in Fortune quite a while ago. He got a poor reception from venture capital until he explained his larger strategies, and then the wallets opened, leading to the acquisition. I hope he puts some of his money into something other than the company.
The home stuff was ridiculously oversold IMO. I read an article about the NEST guy in Fortune quite a while ago. He got a poor reception from venture capital until he explained his larger strategies, and then the wallets opened, leading to the acquisition. I hope he puts some of his money into something other than the company.
Being able to transfer data over a network without requiring human to human nor human to computer interaction will be fabulous.
Its going to take a long time and needs standards, protocols, security etc. Corps with very deep pockets, also. Seems to be in the cards for the future.
-RM
Its going to take a long time and needs standards, protocols, security etc. Corps with very deep pockets, also. Seems to be in the cards for the future.
-RM
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But what do you call something that is autonomously connected to computers but not on the internet? The government in UK are planning to roll out 55 million smart metering points. No internet involved. I still will resist having one as the system isn't being rolled out to help the consumer.
If only. Mostly it's taking things that worked and screwing them up by putting them in the cloud!
IoT was and is hugely overstated - especially the HA part of it. Talk about hype!
The only people that will make money out of it are the system integrators and top level software platform providers like SAP, IBM etc where some useful stuff can be done. I saw prices on 32 bit Zigbee micro controllers go from $3-00 to $1.20 over 2 years. It'll be even lower now.
I'm very glad to have put it behind me along with God knows how many customer visits, requests to tweak a 100k byte Zigbee stack to suit some oddball application, speeches at Computex blah blah
Mugs game. Period.
The only people that will make money out of it are the system integrators and top level software platform providers like SAP, IBM etc where some useful stuff can be done. I saw prices on 32 bit Zigbee micro controllers go from $3-00 to $1.20 over 2 years. It'll be even lower now.
I'm very glad to have put it behind me along with God knows how many customer visits, requests to tweak a 100k byte Zigbee stack to suit some oddball application, speeches at Computex blah blah
Mugs game. Period.
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Yup. And actually that always was the case. Course I had to nearly bankrupt myself to realise that. Currently with one of said SI firms.
But if they beat the drum hard and long enough , IOT will usher in "hardware
as a service"(HAAS). Monthly/yearly fee to toast your bread.
https://azure.microsoft.com/en-us/documentation/articles/iot-hub-operations-monitoring/
"Device telemetry" (to cloud) is very "worked out". Same as W10 , HAAS/
SAAS ---- cloud will happen.
An analogy would be global warming , hundreds of stories a day saying it is true , or "you need this" .... erodes into the sub-conscience.
No , a further monetization of things that currently make no money for IT.
Google Wants to Put Ads in Your Refrigerator | TIME
Five ways to bring advertising to life in the internet of things | Media Network | The Guardian
IOT sneakers and underwear and jackets.
IOT cars will be the biggest ... riding around with your plastic , pass by a
retailer - get an ad. Pay extra for the luxury (opt-out) to drive around ad-free.
OS
http://www.pge.com/en/myhome/customerservice/smartmeter/howitworks/index.page
Well , look at that ... the access point is the powerline , the provider has
the endpoint , and they are connected to the WWW.
No way around it. They are setting themselves up for a cyber warfare
infrastructure attack.
It also looks like the electrical grid itself is being prepared for IOT in certain
regions.
OS
The power company came by about a month ago or so and upgraded the meter so they no longer have to come and read the meter. Just sends out an RF signal with the power usage, no more meter readers, another job bites the dust. If you didn't want that you had to pay a higher monthly bill if they had to drive by and check the meter by car. They were already a wired device so they didn't have to come into the side yard and read the meter, now they don't even have to walk down the street and collect the meter reading, it is all cellular now.
Internet of Things Connecting to Smart Meters | SIGFOX
Full IOT "remote disconnect" !
Looks like a combo of special longer "blockproof" waves , since IOT only needs
to send small data.
Looks like Europe is fully covered - all ready for dystopia ~.
OS
Full IOT "remote disconnect" !
Looks like a combo of special longer "blockproof" waves , since IOT only needs
to send small data.
Looks like Europe is fully covered - all ready for dystopia ~.
OS
might want to keep an eye on this sort of thing / what they did in the '805' -
Smart meter fallout continues | November 1, 2012 | [url]www.toacorn.com | Thousand Oaks Acorn[/url]
the 805, just past the hill, in the distance -
An externally hosted image should be here but it was not working when we last tested it.
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