The total harmonic distortion at the connection point to a house in Australia and other countries can be as high as 8%, and still comply with the The Institute of Electrical and Electronics Engineers IEEE519 recommendations for mains supply. My sine-wave inverter has a maximum THD of <3% from 0% to 200% of rated load irrespective of the load profile.
Voltage waveform distortion including harmonic distortion results from the operation of appliances or equipment that draw non-sinusoidal currents from the network. Harmonic distortion can cause the supply voltage to depart from a sine wave in a repetitive manner. When waveform distortion is outside acceptable limits it can cause interference and damage to sensitive customer and network equipment. This form of distortion can also cause light flicker, incorrect operation of ripple control devices (used for off peak electric water) and computers, audible noise in television, radio and audio equipment and vibration in induction motors.
Customers with sensitive equipment may need to install devices to protect it, e.g. a line filter or an appropriately designed uninterruptible power supply.
Below are the allowed levels for individual harmonic voltages in low voltage networks at the customer's service connection point.
Voltage waveform distortion including harmonic distortion results from the operation of appliances or equipment that draw non-sinusoidal currents from the network. Harmonic distortion can cause the supply voltage to depart from a sine wave in a repetitive manner. When waveform distortion is outside acceptable limits it can cause interference and damage to sensitive customer and network equipment. This form of distortion can also cause light flicker, incorrect operation of ripple control devices (used for off peak electric water) and computers, audible noise in television, radio and audio equipment and vibration in induction motors.
Customers with sensitive equipment may need to install devices to protect it, e.g. a line filter or an appropriately designed uninterruptible power supply.
Below are the allowed levels for individual harmonic voltages in low voltage networks at the customer's service connection point.
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Ha ha, I was being audacious! The inverter I mentioned is the primary electricity supply for my off-grid property. It's a Selectronic SPPro SPMC481-AU. It's easy enough to dedicate the inverter to the hifi; all I have to do is turn off the breakers for everything else. I also have a Selectonic SE42 3kW inverter with similar quality specs used it to charge the car.
I live on an island where the mains supply is SWER (single wire earth return) and quite unreliable due to lightning strikes and other transmission failures, so I made the decision 5 years ago to pull the plug from the electricity network and be grid independent.
Before I moved here I did intend to run a double conversion UPS because where I was in the centre of a large city there is an enormous amount of rubbish on the mains electricity supply, caused by industrial machinery users (I was very close to a chocolate factory), feed-in solar systems, domestic air conditioning units, etc. My budget for a UPS was non-existent, however most of my non-Mac computer equipment (desktops, laptops, memory chips, software, etc) came out of the e-waste bins from the headquarters of a large company nearby, which tossed out all their stuff at ~2 years old. Unfortunately I missed out on ever finding a suitable UPS. The Peach Audio studio line filter I mentioned would have been eminently suitable also, however I didn't have the budget for that either.
To be honest, properly designed and interconnected audio equipment is (or should be) immune to noise on the supply side, however individual units often are not, and it is normally beyond the resources of the end user to 'open the bonnet' and correct poor engineering practice inside tuners, DACs, amplifiers, etc, and sometimes it is actually impossible to undo bad circuit layout. In a previous life when I was technical manager of audio for a performing arts organisation with tens of thousands of pieces of audio equipment, my department's techs just opened up everything we bought and fixed any design issues. In fact we often fixed equipment that didn't even belong to us; we had hundreds of touring troupes in our venues each year and the public held us responsible for sound quality issues even when they brought their own gear!
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You could use a motor generator set, better in noise performance than a sine wave inverter. Harmonics in noise are also to be considered.
Members having experience with IGBT drives with pure sine wave output please add their experience, and points of view.
Members having experience with IGBT drives with pure sine wave output please add their experience, and points of view.
Go buy used sine online UPS 1kW+ power range. Then you have inverter generated good sine wave power. The more advanced the unit is the better. Brand new ones are kinda expensive. Whether or not it will be less noisy than a grid is to be seen. Designing a goof filter for sine inverter is a task of itself and may require special conditions to even check the performance.
for instance
https://www.ebay.com/itm/390309738993?epid=133932680&hash=item5ae045f9f1:g:VDIAAOSw6O9eef6U
for instance
https://www.ebay.com/itm/390309738993?epid=133932680&hash=item5ae045f9f1:g:VDIAAOSw6O9eef6U
A motor generator is a motor driving a dynamo or alternator.
Was used to get different output voltages or frequencies in the old days.
https://www.google.com/url?sa=t&rct...%93generator&usg=AOvVaw02_uT_nLZvewmSJtcob4kU
Was used to get different output voltages or frequencies in the old days.
https://www.google.com/url?sa=t&rct...%93generator&usg=AOvVaw02_uT_nLZvewmSJtcob4kU
APC is a business now owned by Schneider, I think.
In the old days, they were average, the sine wave is a modified (stepped) square wave.
Check the THD and load / no load performance in the above unit's specifications before thinking of buying one.
In the old days, they were average, the sine wave is a modified (stepped) square wave.
Check the THD and load / no load performance in the above unit's specifications before thinking of buying one.
I am not sure about M–G set cause the production seized perhaps in 70-s. Umformers are usually used for 400Hz @ airports. Last time I've seen MG sets it was UPS for mainframes like IBM-360.
I have this sound card. The click you hear is a relay - there are different output modes based on speakers/headphones or line. I got rid of my hum/noise by using the S/PDIF output and an external DAC. Galvanic isolation also works but digital was cheaper.
Except when dealing with AM radio which is completely useless in my place due to stray EMI (the entire AM band is a loud 60Hz hum here).
You can make a M-G set, use an old compressor base plate,or something similar, rig a mains motor to drive an alternator from a car with a V belt.
This is a DIY forum...!
This is a DIY forum...!
Inside any building surrounded by its wiring is no place for an AM antenna. Make a weatherproof loop for outside and connect it to your tuner with coaxial cable (TV cable is fine) and you can have good hum free AM.
A pure sine inverter/storage battery alternative to try first? Augmented grounding. A solid low impedance earth ground makes a big difference. Multiple copper plates buried horizontally like irrigation lines, with soil amendments if needed. Brazed 10ga bare copper leads running to a solid copper ground post with more brazed connections. Preferably under something that needs to be watered on a regular basis. So many things are reliant upon a solid earth ground, and almost no one has one at home. Even if it doesn't make your stuff sound better, surge protectors will actually work, etc. IMHO
I live in Toronto. AM and hum free are mutually exclusive here, even in the car. 740AM is so bad in the downtown that they added a 1kW FM repeater for it on 96.7MHz 🙂
I visited The Hummingbird Centre (now called Meridian Hall) back in 1998 as part of a world tour studying variable acoustics for auditoria and a mate of mine from Sydney, Neil Wilson was NAD's international marketing manager based in Toronto . I love the underground malls. However I'm sure the physics of AM radio reception works the same there as other cities.
There obviously some reason why an AM station that can be heard from "Kingston to Windsor, Perry Sound to Pittsburgh" doesn't work in DT Toronto... The FM repeater has an ERP of 22.4 Watts...
https://www.zoomerradio.ca/faq
https://www.zoomerradio.ca/faq