DIY Low EMF 5 step Sine Inverter

[BruceM]

Thanks, Glort.  Because of MS and autoimmune thyroid disease that has caused alternating episodes of hypo and hyper thyroid, depression has often been a serious problem for me.  Just in the last year, I found that by taking just 1/4 grain of natural (pig) thyroid plus Cynomel by Grossman, I can manage and not have the horrible aggravation of my epilepsy that thyroid meds have always caused.  I need something that's in the natural stuff, but only a little.  The Grossman generic Cytomel feels MUCH better to me, is head and shoulders above the US generics, and 1/4 the price.  When I'm naturally hyperthyroid, my epilepsy is markedly better (7 years was my longest stretch), despite the difficulty in sleeping; so I know the thyroid medications are the culprit.

"Modern" medicine assumes that hormones that are not the same as your natural ones, but are similar molecules that can be patented, must be good enough, even when patients claim otherwise.  I think that's nonsense, and that for profit medicine with it's patent medicines is hardly in the best interest of the public.  I have similar problems with the hydrocortisone I inject.  It's NOT the same as having normal adrenal output, and even in injectable form causes gastric distress, yet for me, compared to the other two patented synthetic analogs to cortisol, dexamethasone and prednisone it is the lesser of evils. 

I'd sure like to see truely bioidentical hormones available; I think millions would benefit greatly.  Right now our  pharma industry with their regulatory capture makes that impossible,  as does their control of the legislature.

Depression has a dozen different causes, biologically, and is serious business. It may be the harbinger of neuro-degenerative diseases. The conventional approach of just giving SSRI drugs for "depression" will be viewed in the future as dark ages, incompetent medicine.  I highly suggest reading Datis Kharrazian's books.  His functional medicine approach, in looking deeper for the underlying problem, may not be as profitable as 8 minute medicine, but seems a hell of a lot better for the patient.

[glort]

Yeah, have had SSRI's. I WILL tell any doctor that suggests them to stick them in their Khyber pass and walk out because clearly they have no clue.

I know exactly what is wrong with me and causing my problems. I keep telling them i'm like a plate dropped on the kitchen floor. once it's shattered isn't any amount of super glue going to put it back the same but I guess it would be good to be a bit less broken.

I don't like taking any of that stuff or anything else unless I really need it.  Not crying every day atm so been giving it a rest. See what the only Doc I trust says on monday.

[BruceM]

Neurology and Psychiatry are both still pretty much dark ages.  They apply labels to symptoms and call that a diagnosis, and then start trying drugs at random.  There is no science to what drugs may temporarily help for someone and what will not, or worse.  All you can do is just keep trying.  I had a horror show for a life for a few years, trying drug after drug to try to get some control of my epilepsy while new MS lesions were showing at every new MRI. The horrible depression of being seriously autoimmune-hypothyroid, just taking enough Cytomel to keep me from suicide, since taking more turned up the epilepsy dangerously.  The rapid downward slide gradually stopped when someone visited with a meter, showed me the high readings. and I cleaned up my home, EMF wise.  A lot of misery and holes in my brain for the lack of a couple wire nuts in the right boxes.  I owe my life to the person who spoke up and stuck a meter in my face.

Doing laundry on the inverter with the latest software version now.  Did some checking and found an issue I have to work on besides cleaning up some EMI.  The PV charge regulation is going oscillatory at higher loads- this in the late AM when there is plenty of excess amps beyond what the inverter is calling for.  I see a 1V peak to peak sine ripple at about 6.6Hz on the 120VDC.  The battery regulators are flashing visibly.  This is the hassle of closed loop analog control systems.  I can twiddle with the values of the net charge dampening term...I suspect that when I last jacked that up to improve response to sudden shedding or adding of 1200W loads, I may have affected stability for the minutely pulsing nature of the inverter. It's going to take some time to sort it out.   I have a solderless breadboard that can take over that part of the control, getting the essential signals from the PCB and generating the drive signal for the PV current regulator.  I just hope I can make it happen without the inverter on, as I can't stand there for more than 30 seconds with that on.

[glort]

 trying drug after drug to try to get some control of my epilepsy while new MS lesions were showing at every new MRI. The horrible depression of being seriously autoimmune-hypothyroid, just taking enough Cytomel to keep me from suicide, since taking more turned up the epilepsy dangerously.  The rapid downward slide gradually stopped when someone visited with a meter, showed me the high readings. and I cleaned up my home, EMF wise.

Eliminating the EMF stopped/ Slowed your MS and Epilepsy?
That's huge!


Must be standard medical practice to throw Drugs at people. I have had the same thing " We'll try this and see how it goes. If it doesen't work, don't worry, there are 54 other poisons  we can give you and one of them will suit you.  Or kill you in the process which will eliminate the problem anyway so all good".

They all sound like 2nd rate car mechanics..... " we'll just keep changing parts till the problem goes away.".

[BruceM]

The other thing I found very helpful in the last year is the Gundry low lectin diet. Reduced my headaches, brain fog and muscle pain dramatically.  Don't think I could have finished the inverter project otherwise.  Software was beyond me, totally.

Learned an important lesson today.  I forgot and started the inverter with the step down transformer turned on.  The new soft start can't handle that either, it blew the 16a fuse for each h-bridge, and the same two mosfets on each board.  No other casualties.  I MUST add a time delay relay control to the output so that soft start is ALWAYS with no loads.

 

[BruceM]

More EMI testing and DC ripple measurement today  led to an annoying discovery.  I use 4- 800 w toroidal step down transformers in parallel (not ideal) outside the shop to get 120VAC for the washing machine, a friend's welder, etc.  On occasion, when remotely switching on those transformers via relay, I get the same old toroid transformer inrush current spike- and it blew fuses and 3 mosfets.  So I will have to add a relay time delay controller (Siemens), another relay, and 400 watts of 50 ohm resistors.  The resistors will limit the start current, then the relay will short them out after 3 seconds. 

Toroids are very efficient, and a bit of a pain.

[glort]

Maybe using much cheaper/ thinner wire from the batteries would help Bruce?
A bit of inbuilt resistance to slow the current down?

That's the problem with quality installations, they work too well. If you did it china style with wire barely thicker than a human hair, you wouldn't have these Inrush Current problems! 

 

[BruceM]

Yes, when I did all my testing, there was a long 12 gauge pair leading from the shop bench to the 230V outlet, which was also 12 gauge back to the shop power panel, and I think 12 or 10 gauge to to the power pedestal in the hard with the transformers.

Now that I'm thinking about voltage losses, and everything is beefed up, it's been an eye opener how high the inrush currents can be for the higher efficiency toroids. The ST-3 never complained.

I found out something interesting today-  I had almost 20 millivolts peak to peak of AC waveform riding on top of my 120VDC when the inverter was running and no other DC load in the shop...and it didn't change in the slightest from no load to 1500 watts load! It took me a bit to realize what was going on.

 The problem is that I ran both AC and DC as 6 AWG twisted pairs in the same metal conduit (something I avoided for my neighbors setup) down the hill about 250 feet...and the 230VAC signal is coupling capacitively onto the DC line.  I'll have to add capacitance from 0, and120VDC to ground at the power pedestal to help remove the AC.  It should be well below 1 millivolt!  The luxury of DC is that there is no loss or performance penalty for adding capacitance.  I rely on clean 120VDC, it lets me use soldering irons and other resistive appliances with no health problems.

There's that old saying about 90% of the project completed, but that last 10% takes 90% of the time.

[glort]

That seems like a lot of crossover ripple but then again with 250ft of of run,  there is plenty of area for it to induct.
Will adding caps take out all the ripple or will you need to add anything else in?
With my limited knowledge I would have thought the batteries would have damped that but maybe it gets worse as it gets closer to the house and there is less damping effect of the batteries.

The 90/10 Rule sure applies to a lot of things but I always find that last bit of a project the most time consuming and invariably frustrating.
Was working on something this afternoon that took so much time for so little result where as all the other went like a dream .
Should have known.

[ajaffa1]

Hey BruceM, sorry to here you have had such a rough time with your mental/physical health and the Medical professionals that are supposed to help.

I have had similar experiences and wonder at the way pills are randomly trialed on the sick. My doctor tried to prescribed a drug called lyrica, for nerve pain. I declined his kind offer as I knew that this product can cause heart attacks and I`ve already had one. He then put me on an antidepressant called Sertraline which put me back in hospital with blood pressure issues.

I went to see the cardiologist today for a check up, told him what had happened and he was appalled that my GP had tried these medications on me without consulting him.

There are some very smart doctors out there who can help, the difficulty is finding them and then having the courage to tell the mediocre medics to take a running jump.

The best news today is that I have been taken off the blood thinners. I will no longer bleed for a week from an insect bite or develop a haematoma instead of a bruise. Happy days 

Keep up the good work, chin up,

Bob

[glort]

Glad to hear some good news for you Bob. That's definitely a step in the right direction.

I have had a specialist tell me much the same thing, nearly had a fit when I told him what I had been given. I think was somewhat pissed off with the GP who gave them to me. Said they should never have been prescribed for you and that should have been obvious.

I learned to stand up to doctors a long time ago.
My grandmother took me in when I was 12.  When I was older I looked after her.  I remember her having breathing troubles one time. She was so short of breath she was crying thinking she was going to die.  Put her in the car and got her to the hospital faster than any ambulance would have.  Kept her for about 6 Hours then said she is OK to go home.

3rd time in under a week I told them straight out, I'm not taking her home. I don't know what your tests tell you but my eyes tell me when she is sitting in the chair and can't get her breath there is something wrong and still is. You need to keep her overnight. They said we have no beds. I looked at gran and said looks like you are spending the night in the hallway. Told them again, I am not taking her home to die while i'm in the shower or out the yard.   After an hour they came back and begrudgingly said we found her a bed but we can only keep her in one night.
I said fine.  They released her 3 days later after they drained the water off her lungs that was almost drowning her which they found when she had ANOTHER attack and they looked her over properly. 

I never held back on saying my piece to medicos since.
After that I looked after my father in law when he had cancer.  Same deal, they tried to fob him off at different times. I bet they hated me because i didn't let them get away with a thing.  I was surprised they let me back in the hospital given some of the enthusiastic discussions I had with his doctors and particularly nurses.

I was at it again the other week. Discovered a Nurse left my Mrs in the middle of getting her out of bed in a very uncomfortable position which caused her a lot of pain.  Same nurse later in the day also Missed the fact the IV in her hand was running to fast and tissued.  I'm an idiot not a medically trained person and If I could spot this, the nurses in a private hospital bloody well ought to.  I went and saw the head Nurse unbeknown to my wife and found out the nurse that was responsible was a trainee.  I made my displeasure very clear in a very calm and polite manner and told them that this nurse was NOT to go near my wife again without a qualified person supervising and if I found she had, I would take it further. I told her I did have the time and money to be a pain in their arse they would wish they never upset.  Mrs never saw that nurse again. Also rang the surgeon and relayed my concerns to him and he kicked some butt as well.

After too many bad reactions to the poison they hand out I NEVER take a damn thing without looking it up on Mimms to see what the heck it is and the side effects. I'll admit that's only partially useful as they all list so many things it sort of becomes a bit of a moot point.  Does prevent some surprises though.
I went to the only doc I trust on Monday and came away with a showbag of sample drugs he's changing me over to.  Been off the anti depressants about 6 weeks when I ran out and thought I was doing OK.  3 days back on them and I'm up the shed crying again. Mrs said I was better with them, more motivated but I'm not so sure.  I didn't seem to be thinking about things as much but now it seems all I can think about again.  Hard to tell though, I'm up and down through phases like a Yo yo.  Just went through a numb phase where I didn't feel anything, Now I feel like I'm going to back to crying at the drop of a hat.

I think my doc is getting ready to retire. That will be depressing.  This guy is alike a best mate with medical qualifications.  He motivates me which is more powerful than anything that comes out a box.  He's also never set a foot wrong with what he has given me so it will take a lot to trust someone else.

I think Bruce is on the right track in doing a lot of his own research and self help.  Medicine is too much about making money from the pills and potions these days.

There was a line on a TV comedy show I saw a while back.  Was a Chemist that worked for a big pharma company replying to a friend asking how was her day at work.  She said great, I invented a new condition and a cure for it all in one day.
It was supposed to be satire but the truth in it was frighteningly poignant.

[BruceM]

I think good medical practice is an extreme exception, rather than the norm. I've seen so much blatant, basic malpractice it's outrageous.  Trusting any medical practitioner is a fools paradise, in my book.  It's your health, and MUCH can be done to help yourself. 

I'm keeping an open mind on the cause of the AC ripple on the DC.  But I know it was NOT there in my bench testing; I had it down to 1-2 millivolts peak to peak at 1000 watts at the end of about 300 feet of cable.  I was expecting an unmeasureable situation with the inverter near the battery bank.  But given the constant level of AC ripple regardless of load, it is almost certainly capacitively coupling from the constant 230VAC pair in the same metal conduit.  I was foolish to have not run a separate conduit for AC.

[BruceM]

Not fully believing my own findings (I was still recovering from a trip to town.) I retested today and find results similar to the bench testing. AC ripple on 120vdc supply of about 3 mv p-p at 1000w load, 1mv with 500w.  I suspect operator error or a bad test lead before.

EMI on DC is non-existant,  AC is barely there with AM radio oriented just right a few inches from the wire and tuned just right to the lowest portion of the AM band under even small load.

The EMI is around 1MHz, so as one should expect, it didn't significantly jump to the DC wires in the same conduit, or what did is the same as what bled off to the buried metal conduit.

This is substantially better than my partially EMI suppressed Listeroid/ST-3 power.

I have yet to add the 0.1 ohm capacitors to ground on the H bridge output filter boards, which I will try, since the earth grounding system was such a project! Right now they are just a toroidal common mode choke and snubber.  The only ground connection at present is the center connection of the two transformer secondaries. 

[ajaffa1]

Hi BruceM, used to get the same sort of problems with control cables in factories, always ran unshielded twisted pairs at least a meter away from single or three phase cables. The worst offender was florescent lighting with starter modules.

Where we had no choice but to lay cabling next to power cables, we ran shielded cables all grounded to earth. Gets real expensive in some situations where you might need 30 or more control/data wires.

Bob

[BruceM]

Hi Bob, Yep, industrial control is often one of the worst EMI environments out there; fiber, both plastic and mulitmode glass, has made big inroads there for good reason.  I use Industrial Fiber Optics POF products for both analog/control and digital data regularly. My home's audio, thermostat, central vac, computer on/IR controls, keyboard/trackball and IR rear projection controls are all IFO product based, my own designs.  In my case it's because the home is shielded to -110dB so all signals have to either be filtered or fiber. 

Today I did add 0.01 uF caps to the earthing system on the AC output of the H-bridges.  Connection was easy as I ran sheet copper (16 oz/SF copper flashing) up behind the steel box and could just screw to the box and copper anywhere. It did improve both the DC (nothing audible at all now) and AC.  AC with any load is only audible on the AM radio around 560KHz, within 1/2 inch of the wire with the radio oriented just right.  No load EMI on the 230VAC can be picked up at 6 inches.  I'll have to think about that one.  During testing I experimented with a snubber on the AC output, a motor run cap about 6 uF and 2-10 ohms on my earlier 120V version.  It worked well but I don't like that solution as it's a power sucker.

I thought about adding the 4 - 250 uH toroidal chokes to the 2 h-bridge output filter boards again.  The chokes "round the corners" of the stepped waveform quite nicely but do nothing for the EMI whatsoever.  They do get hot at full load and add about 1% power loss. While the waveform is softer, it doesn't do anything appreciable for THD or motor efficiency so I'm reluctant to add them in.