high frequency transients/dirty electricity

debra · May 2015

I'm looking for a solution to the high frequency transients or harmonics that are said to be created by most inverters. I've heard they are unhealthy to be around and that it's better to be all DC, but feel there must be a solution to the "harmonics" on the sine wave of inverters. Does any one know anything about this?
Debra

froggersix · May 2015

dont worry about it. good sine inverters have better bpower output than utility anbd even if they didn't the distortion is not a health problem thats just nonsense.

BB. · May 2015

Hi Debra,

There are many folks that believe they are negatively affected by various electromagnetic waves...

The entire radio spectrum runs from very low frequency (50/60 Hz power lines, 3-30 kHz VLF for submarine communications) on up through standard ratio bands to light, to xray and beyond.

In general, it helps to have an idea of what is the frequency range of concern.

When dealing with power systems (generators, utility power, MSW and TSW AC inverters, computer networks, various power systems/loads, etc.)--They all have their own profiles.

Some people are very concerned about power line frequencies (60 Hz + some harmonics out to 500 Hz or so)... Others are worried about cell phones and WIFI (800 MHz to 5.0 GHz). These are wildly different frequency ranges and have quite different effects. And the distance and power levels from the wiring to the human matters too (a low power electric blanket on the body; or a high power hair drier is different from a small computer running a USB charger/power cord).

So--What are your specific concerns and what are the types of loads you want to use?

-Bil

debra · May 2015

I've listened to interviews with Dave Stetzer of Stetzer Electric and Samuel Milham (epidemiologist) and others who are concerned about the health effects of high frequency transients. When there's a sudden load on our system, there's a pop that comes out of a small speaker. I'm assuming, based on what little I know, that there are constant surges happening with lesser loads. I have had bacterial, viral,parasitic, yeast infections for years and have been told that there's a link with exposure to electromagnetic fields and infections that are very resistant to elimination.

Dave Angelini · May 2015

debra wrote: »

I've listened to interviews with Dave Stetzer of Stetzer Electric and Samuel Milham (epidemiologist) and others who are concerned about the health effects of high frequency transients. When there's a sudden load on our system, there's a pop that comes out of a small speaker. I'm assuming, based on what little I know, that there are constant surges happening with lesser loads. I have had bacterial, viral,parasitic, yeast infections for years and have been told that there's a link with exposure to electromagnetic fields and infections that are very resistant to elimination.

How close are you to the inverter? After 3 feet or so it dissipates quite a bit. How about cell phones also? What brand of inverter as there are different topologies that radiate different frequencies of RF?

Is the small speaker pop connected to an AM radio? I have heard of similar issues and in the end the person decided to eliminate AC in their house and use DC appliances. I did not get a diffinitive answer if this worked for them. Good luck

BB. · May 2015

In general, transients are so short of time that they have very little physical effects on our bodies. It is the long term exposure that tends to be more of an issue.

There are certainly problems with transients, "dirty power", and MSW (modified square wave) inverters... However, those are mostly concerns of engineers and owners of the equipment. Designing equipment to "ride through" transients, Active Power Factor Correction for electronic power supplies/passive power factor correction for induction motors (using capacitors), lightning strike issues, radio interference, etc. are all real.

The "pop" you hear in a speaker on an AM radio is an amplified (1-10+ audio watts) signal that is a radio frequency event that may be 1/1,000 to 1/1,000,000 Watts (milli and micro Volt) events...

A WIFI and Cell Phone transmitter may transmit as much as 1 Watt (legally, although you can get long range WIFI devices that are up towards 60 Watts or so). A microwave oven has a ~1,000 Watt "transmitter" inside.

An old CB radio transmits a maximum of 4-5 watts. A HAM radio can range from well under 1 Watt to 5 Watts (hand held typical) to 1,200 Watts maximum (larger HAM transmitters need to be studied/measured to ensure they do not exceed FCC human body exposure limits).

https://en.wikipedia.org/wiki/Mobile...ion_and_health

Frequency also has a huge effect on how the radio frequency energy "couples" to the human body... Attachment not found.

Low frequency "noise" have very long wave lengths. Typically the 1/4 Wave Length is what engineers worry about (energy coupling becomes efficient at 1/4 wave lengths). A 60 Hz open air 1/4 wave length is something like 776 Miles long.

A 2.4 GHz 1/4 wave length is 1.23 inches long--Much closer to the size of parts of the human body--And why we use 2.4 GHz microwaves instead of 60 Hz waves to heat our food.

And as Dave A. says... The farther you are from something, the less the energy density... Basically, is the inverse square law. A hair drier is 2 inches from your head. The wires in your wall may be 20 inches away:

(2 inches/20 inches)² = 1/100 times less energy (20 dB reduction--deciBels a common engineering unit used for radio waves)

I am not trying to minimize concerns of people (in a way, I am of course)--But trying to narrow down your area of concern (what devices you are worried about, what frequencies, what power levels, etc.).

There are people that have, what appear to be health issues, when exposed to RF energy--But those are (usually) few and far between. Could we be in a huge labratory waiting for 20 year effects (i.e., cell phone/wireless networks/TV and radio transmitters/etc.)--Yea. We could be in for some nasty surprises in the future.

But do not mistake that there are people making lots of money on these concerns... We even had one of those years ago here:

http://forum.solar-electric.com/foru...s-solar-panels

Use "my meter" to see if you have a problem in your home.

One of my jobs years ago was to reduce EMI (electromagnetic interference) from computer systems. You need a spectrum analyzer and a set of antenna to even begin to look at the EMI in your home/area...

http://www.anritsu.com/en-US/Product...rum-Analyzers/
https://www.google.com/search?q=emi+...ih=672&dpr=0.9

This stuff is not cheap....

Remember radios/receivers are capturing very small signals and amplifying/displaying them for our use... It is very difficult to equate "exposure" from a "radio" to what your body will experience.

You can certainly find a remote valley somewhere and have less exposure. When we tested our equipment, we had to go to remote sites that were "quiet" enough for us to accurately see/measure the emissions from our computer systems.

http://www.ckc.com/locations/guide.html

-Bill

Dave Angelini · May 2015

We used CKC also Bill. What years and what facility? Ever get down here to the CKC in Mariposa. Extreme Rural but great to test at night under the milky way.....

Very nice response from you BTW!

At HP we made the EMI test system equipment in the 80's when I was there, I still see it being used with newer software. One of the spectrum analyzers had three fans and could run in a 19" rackbox on one fan. I found a few at customer sites that had been running for 6 months with all the fans plugged with dust. I bet our paths crossed and it might be hard to prove.

BB. · May 2015

Hi Dave,

We used CKC a lot in the late 80s and into the 90s at one place I worked Split time between Mariposa and their Fremont facility (also used a place in southern San Jose too--Always a challenge to find testing time when you needed to test). We were lucky enough to have some parking lot space and spare building/shed for unofficial testing/debugging during development.

Don't remember any HP personnel onsite when testing--But I am sure the HP equipment was more than good enough to be used now--Accuracy and frequency range requirements do not change much (although, with high clock rates, going into multi-GHz much more often now).

-Bill

Dave Angelini · May 2015

Looks like we missed the meeting. I was up in Mariposa in the mid 80's and 2005 to 2013. In between we had to go to El Sugundo and the LA commute that always is a challenge.

We had a nice parking lot for outdoor test at the corner of Stevens Creek Blvd and Lawrence Express way. The old Santa Clara HP division 02.
It is now Agilent's headquarters but I think they have changed their name to Keysight Technology.

Those were fun times back then in test and measurement.

debra · May 2015

Thanks for all the good information that goes over my head for the most part (I may bring it to the attention of local solar business folks). Our inverters (one is Trace, one is Xantrac) are about 55 feet away in a pumphouse. The speaker that pops is hooked up to my husband's computer. It pops when he's out in the shop (hundreds of feet away), using tools that take especially large amounts of power at start-up and sometimes pops when we flush a toilet and the pressurized water tank comes on.

BB. · May 2015

Computer speakers tend to be built "inexpensively"--So they can be very susceptible to "electrical noise". While it is possible that the speaker system is receiving radio frequency interference (some will even receive local AM radio stations). Or, it can be a "ground loop".... Basically electrical noise on the AC power vs the AC green wire ground or even on the Computer signal/ground.

There are many possibilities to address audio interference. Using a small "signal transformer" between the computer audio output and the speaker audio input is a common solution.

http://www.amazon.com/40428-3-5mm-St.../dp/B001DF4GME (look around, this is not a "cheap" unit--You might do better).

And there are AC isolation transformers too (although, I am not sure that this type of transformer would help in this case).

One way that I have found to isolate audio interference (automotive alternator "whine", AM radio leaks, etc.) is to use a WIFI or Bluetooth based satellite speaker system. The digital link between the computer and the speaker box is very immune to interference. If the computer does not have a Bluetooth transceiver -- You can buy a USB Bluetooth adapter pretty cheap.

Do you know if these are just "speakers" plugged into the computer or if these are AC powered (amplified) speakers... Amplified audio systems are very susceptible to audio interference/ground loops and such. And is a different issue vs the concerns that some folk have with "radio frequency pollution" and its effects on the human body.

If you have a monitor, try moving the monitor/cables away from the audio cables. If you have alternate connections (desktop computer with rear and front connectors, etc.). And some computer speaker systems are just poorly designed and need to be replaced with something different/better (Bluetooth, USB, isolation transformers, etc.).

-Bill

Johann · May 2015

debra wrote: »

I've listened to interviews with Dave Stetzer of Stetzer Electric and Samuel Milham (epidemiologist) and others who are concerned about the health effects of high frequency transients. When there's a sudden load on our system, there's a pop that comes out of a small speaker. I'm assuming, based on what little I know, that there are constant surges happening with lesser loads. I have had bacterial, viral,parasitic, yeast infections for years and have been told that there's a link with exposure to electromagnetic fields and infections that are very resistant to elimination.

You are probably taking antibiotics for your yeast infections and those antibiotics are the cause for many women in the first place to have a yest infection and urination tract infections. You may need to talk to a specialist about it. There are other ''antibiotics'' like colloidal silver water that can be used for treatments and other things to balance your chemistry.

If you hear the pop in the speaker, that pop is a tiny arc that jumps across a switch when you turn a light on or off for example. That jumping arc gets amplified and you hear it in the speaker. The inverter can be put in a metal cage and the cage must be grounded and that could lower the radiation. Wires and inverter could be places a few feet further away. I have read that some people are covering theire home with aluminum to shield from outside radiation.

Everyone is different and what may have no affect on me does not mean that it does not affect someone else.

debra · May 2015

Thanks for all your help here. My husband's speaker is connected to his computer. It's power source is an AC power strip. As you suggested, he has seen that moving wires around can help ameliorate the popping (and loud static sounds). More information about our off-grid system is that we have a 4000 watt Sine Wave inverter for the house; and another one for the shop to allow my husband to get 220 there. As far as harmonics/transients on the line, I did a cheap experiment of walking around to lamps, computers, dimable light switches, CD player, television with an AM radio to note high static versus low. Distance from the appliance does make a huge difference. Close up, there was quite a bit of static (with computers and television especially). As far as electrical sensitivity I'm told we're better off being wired in than wireless.
Debra

Johann · May 2015

Here is a you tube about RFI and inverter noise.

debra · May 2015

Thanks very much Johann. In talking to a solar store owner, he also mentioned doing something like what ham radio operators do to reduce "noise".
Debra

waynefromnscanada · May 2015

"debra", please don't drive yourself foolish over this. The "problem" has far more to do with the religious-like beliefs being spread by scaremongers on the internet, than it has to do with the reality of the situation. Unfortunately, once someone has bought into such beliefs, trying to reason with them is often a lost cause.

high frequency transients/dirty electricity

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