Author Topic: DIY Low EMF 5 step Sine Inverter  (Read 1247 times)

BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
DIY Low EMF 5 step Sine Inverter
« on: July 29, 2018, 03:12:30 AM »
I thought I should play nice and quite stuffing this in Glort's PV -grid tie work.  While I did add 1500 watts of panels to my existing 875 for this project, I'm now down to the inverter work.

A little review:

I live off grid and have lived with my own 120VDC system and Listeroid for AC and compressed air for a long time.  In preparation for adding inverter power to my system, I upgraded my 120VDC PV charge regulator to handle up to 3000 marketing watts of PV.  It's linear, not pulsing, for very clean DC.

My 120VDC input inverter design is based on the venerable Trace SW series which does low frequency switching of transformers with secondaries in series to create a sine.  That general concept is about all I'm using.  I'm using very soft (slow) switching plus snubbers and minimal passive filtration to generate AC with no audible (via AM radio) EMI on the AC or DC supply.  I'm only using 2 transformers of equal output secondaries, and they are used to make a 5 step sine wave; zero plus two steps up and two steps down.  I originally did a 7 step sine but found 5 step better. The 5 step sine gets the THD down below my ST3 generator head, and eliminates the typical 20% motor heating loss of a MSW inverter.  I use 120VDC for my home and shop power, and have been using a Listeroid 6/1 for AC generation for well pumping and washing machine.

I have previously done quite a bit of testing of the prototype on motor starting at 120VAC output; it would start a 1.5HP tile saw like grid power, instant and effortless.  I ran into a bunch of trouble when I switched transformers for 230VAC output; ultimately I tracked it down to huge inrush surge current.  Until I worked up a software solution of soft starting the transformers, I could only test by starting the processor and H-bridges with 0 volts input, then switching on the 120VDC through two huge chokes and 30K uF of DC filter caps. This provided a slowly increasing voltage which kept inrush current minimal. The massive DC filter was needed for keeping AC off my clean 120VDC. With the filter in place, I now have 1 millivolt of AC ripple with 1000 watts of load.  Backfeeding 230VAC to my step down transformer outside the shop, I've run a couple loads of laundry in the washer (about 1100 watt load also) with no trouble and barely warm heatsink on the H-bridges.  I've also been testing with 500, 1000, and 1500 watts of heat lamps in the shop.

I got the prototype jury rigged on the floor of the battery bank shed and then found that due to my new short 120VDC supply wires to the 10K uF fiter output capacitor, the old Antek transformer inrush current problem came back and bit me.  I should have tested with small fuses, but I got cocky...with 4 mosfets, 3 ICs, and 2 transistors fried the result.  I got it repaired, changed the soft start to extend from 50 usec to 5 millisecond pulses, and now she starts and stops nicely on small fuses, again.

Tomorrow I'll test on my 1/2 HP Franklin submersible well pump. It pumps from a depth of 200 feet.  It normally runs at 1150 watts, with starting peak over 3400.  The issue to be tested will be surge load capability and compatibility with the operation of the Franklin QD solid state capacitor start relay.


glort

  • Hero Member
  • *****
  • Posts: 2327
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #1 on: July 29, 2018, 08:30:55 AM »

Sounds like you have done something quite unique with this Bruce in what you have been able to do without appreciable EMI.  A lot of enthusiasts build their own inverters now but I have never read of anyone paying attention to the emissions.

Those doing DIY solar argue endlessly about which panels are best and 20 yr warranties etc but the more cluey all agree that the great majority of inverters out there of any type are crap and lucky to work beyond the warranty period.

Would your design be appreciably more expensive to build Commercially in parts or construction than the crappy and over priced inverters out there?
From hat you have said with the components used, I'd guess there is little to no difference other than being a transformer design and the main difference is in the level of engineering design put into it. There was a locally made brand of GTI here that was a transformer design. They are very well regarded and sought by the enthusiasts here dead or alive as they are easy to repair and also to modify for making battery chargers etc.

I have one and the thing looks about 1 Small step above home made. I'm sure the boards were all hand soldered as they look like they were built from a Kit.  They are reliable and well regarded however.

BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #2 on: July 29, 2018, 04:01:13 PM »
My intentionally minimalist design with PICOscope measured 8% THD does not comply with the THD specifications for grid tie inverters (5%).   My primary goal for an off grid inverter was to have the lowest possible EMI, while being able to run single phase induction motors efficiently. I intentionally sacrificed THD to allow for slow switching times and reduced EMI, as long as motor efficiency was not significantly affected; keeping induction motors happy was my requirement.  Most generators are in the 9-15% THD range. My ST-3 THD measured at 12%.  So "generator" class THD was sufficient for my needs, and I did beat that, just, when I got rid of the waveform distortions of slow switching a 7 step sine and went to the simpler 5 step. 

The large toroidal transformers will always be costly, and this will always pressure designers away from this approach, especially when EMI is not even considered.

For the low THD required for GTI inverters, the designer has no choice but to do 100x faster switching, even while using a low frequency design per the original 3 transformer Trace SW series. The sine wave must be built with many small steps; Trace used 32 steps per half wave.   The same Trace SW approach with a modern microcontroller can be done, but even with very well designed snubbing, the faster switching design will require substantially more passive filtering of the AC and DC.  AC filtering in particular is costly in efficiency.  For example, only 10 microfarads of total capacitance line to line at 230VAC draws 1 amp (230 watts) continuously.  Capacitance to ground in microfarad levels is largely a "beat the test" farce since the earthing system in the real world is NOT a copper plane from which all measurements are referenced. Capacitance to ground in larger values, for AC or DC typically just turns the entire grounding system into an EMI radiator. I combat that problem by spending a fortune on the earthing system; I use copper flashing, buried,  with rods connected, and copper flashing extending all the way to the filter enclosure, typically. 

The large toroidal transformers used in my design are heavy and expensive. The mass market for GTI's has driven them to make them smaller, cheaper, lighter.  Low frequency, transformer isolated designs were well proven as being the most durable and reliable. 

My usual plea to those adding inverters to their homes:

To avoid developing Electrical Sensitivity and to greatly reduce the risk of accelerated cancer growth and autoimmune diseases (arthritis, thyroid, diabetes, cardiac) I urge everyone with an inverter (GTI or off grid) to add a commercial grade two stage common mode choke filter to both PV input and AC output.  This will greatly reduce the EMI radiating from the home and PV wiring.  These passive filters are available at any big electronics component supplier, and they run $70-$250 each depending on size.  They will not adversely affect inverter efficiency or performance. They are likely to provide -20 to -30dB worth of filtering up to 50MHz, where must of the switching EMI energy will be.  DO NOT buy plug in "filters" such as Stetzer or Greenwave.   They are nothing but 22uF motor run capacitors and will void the warranty of your inverter, will likely cause it to fail, dramatically reduce it's efficiency and will provide absolutely zero common mode filtering. Anyone promoting them is utterly incompetent, knows nothing of the engineering field of EMC, and should be given a good tar and feather job. 







BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #3 on: July 29, 2018, 08:35:29 PM »
I did the inverter test on my Franklin "1/2 HP" well pump this morning.  Success!  I'm pleased with the results.  It starts faster than on the my ST-3/Listeroid which sags a little.  Running current at 235V was down to 5.9 amps in 2 seconds for a total of 1386 watts. That's a bit higher than expected but the pump is over 10 years old and main winding resistance is out of range, slightly.  The pump controller lid specs say 6 amps at 230VAC, even though Franklin literature claims 1150 watts for the pump. 

I did a comparison to ST-3/ Listeroid power. With the same RMS volts and RMS clamp on amp meters in place; results- 6.1 amps 232VAC.  1415 watts.   The frequency was 60.1 Hz which might account for the small increase. Certainly the inverter has performed at least as well as ST-3 generator for motor driving efficiency.

I did find a software bug which is intermittently affecting remote shut down.  Otherwise, I'm ready to get on with proper job of packaging and installation; at present it is just a jury rig of boards and wires on the floor of the shed.








glort

  • Hero Member
  • *****
  • Posts: 2327
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #4 on: July 29, 2018, 11:48:17 PM »
I did the inverter test on my Franklin "1/2 HP" well pump this morning.
 5.9 amps in 2 seconds for a total of 1386 watts.


Is the Motor Half Horsepower or 1 to 2 Hp?
I always thought a horsepower was 746 watt making a half HP motor about 375.  1386w is just on 2 hp to me.

Do you have any links to the chokes you mention in the previous post for the inverters so I can see what they look like for substitutes?
I went to repair an inverter the other week and it seemed to have a Big Choke on the output wiring. As an amateur Hacker, I would have never stuffed the wiring in the messy, unorganised and what looked like stressful to other components in the way this thing was built.
Stupid design, required disassembly of most of the unit to get to ANYTHING in there or on the board.

Spose it's all made to be as light, cheap and compact as possible and it the thing is painful to repair, that's just more hour booked up to the client and revenue for service ion the back end of the sale.

Having opened a few different makes and types of these GTI;s  even as a pelican it's not hard to understand why they have such short service lives.
My main inverter runs too hot to touch when it's making anything over about 3KW from it's 5Kw rating.  No way in hell baking electronics like that is a good thing.  I have a big tube fan and a sensor on the thing so once it hits 40oC the fan kicks in.  The efficiency of the thing belies the amount of heat coming off it that's for sure.


BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #5 on: July 30, 2018, 02:24:51 AM »
Franklin rates it's submersible motors on pumping HP, apparently.  It's nuts.  The rated current/volts for their "1/2 HP" is more typical for a 1.5 to 2 HP motor.  Don't ask my why.  Horse power is generally untrustworthy in American marketing- you can only look at rated current and voltage and service factor and go from there. 

For the typical two stage commercial filter power filters, here's a page full of models about right for a 5KW output GTI.  If you drill down further you will see that the more expensive ones use larger common mode chokes, which have better performance, especially at lower frequencies.  Data sheets give you an insertion loss plot for each one.  I make my own filters, but I wanted to keep this simple for those who might be daunted.  They are not that expensive and even the cheapest one's will reduce the home power EMI dramatically. 

https://www.digikey.com/products/en/filters/power-line-filter-modules/838?k=&pkeyword=&pv2155=u25A&pv2155=u30A&pv2155=u36A&FV=ffe00346%2C5400d2%2C33c02b2&quantity=0&ColumnSort=0&page=1&stock=1&pageSize=25

For  installation, these need to be mounted inside a junction box, since the terminals are exposed.

Commercial electronics are not designed for ease of maintenance, just as cars are not anymore, either. It's all about the race to the bottom.  When I build something, the components alone might cost me 20 times the price of a finished product from China, and they have a custom molded plastic case.   

The challenge for my inverter install is to make it easy for myself for any troubleshooting and maintenance.  I have the luxury of not caring about size, weight.  I want to locate the two H-bridges so I have ready access the top side of the boards for o-scope checkout; the processor board can just unplug, and I'll add some test points on the top side of the power control/remote control board.  The little voltage sense transformer plus rectifier for computing RMS voltage needs a top side test point also.  Fortunately, what commercially would be stuffed in a small shoebox, I'm putting in a 15x15x6 inch box.  I haven't decided on whether the heat sink should be split in two and extend outside the box, or whether I'll just have lots of screened vents on the box and let the heat sink help drive the thermally driven airflow.  The latter probably, as it gives me better access.

I was too scramble brained from the live testing this AM to do the software debug work.  Hopefully tomorrow AM I'll be smarter.   It's the damned grossly overtaxed RMS voltage routine that's got the bug- that makes it ignore the shut down request signal...after traversing the voltage timing table upwards to a large amount.  I'm going to have to do some recording with the Picoscope logic analyzer function again, while flipping some spare port bits in the code so I can figure out what's happening in real time.  I'll be able to use an Arduino Uno board hooked up to a breadboard for simulating a few signals and a pot for AC sense voltage.  It would just be a whole lot faster if I didn't have to go into the house to operate the picoscope, but I can't work near it or the computer.
















glort

  • Hero Member
  • *****
  • Posts: 2327
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #6 on: July 30, 2018, 04:15:11 AM »

 Horse power is generally untrustworthy in American marketing- you can only look at rated current and voltage and service factor and go from there. 

HAHA!
Have you ever looked at chinese power ratings?  they just put a bigger number on whatever than the other guy. NO semblance to reality at all.
There are so many inverters on Fleabay  that are say 12v, 1000W and use a 25A fuse.  You don't even have to look at the efficiency to see that don't add up by a country Mile.

Of course then you have the no name 10 Ah 18650 Cells that even the likes of panasonic have only been able to achive about 3500Mah and the Lipo jumper packs that are 53,0000 Mah and fit in your shirt Pocket. Why the likes of Tesla haven't got onto them I don't know.
Apart from the fact they are complete and utter fantasy of course.   :laugh:


Quote
For the typical two stage commercial filter power filters, here's a page full of models about right for a 5KW output GTI.
For  installation, these need to be mounted inside a junction box, since the terminals are exposed.

They aren't what I thought so I don't have any spare.  I have put a lot of Junction boxes in here. Always splitting or tapping into some Circuit.
When I need things like Boxes , terminals and cover plates now I go to the dumpster round the back of the local solar installers. Just stuns me what these guys throw away. All brand new still in the plastic bags.  I have more good quality breakers in single and 3 phase of different ratings than I knew existed sitting on  my now electrical shelveS  that ever before and I got them all out of the bin.  Same with Tech Screws. Must come with the mounting rails for the solar or something but I always pick up 2  or 4 bags of the things and they aren't cheap to buy.

Called in there the other weekend on the way to the hardware.  Got a load of stuff.  Started going home and the Mrs says  what about the hardware place? I said Idon't need to go now, I got everything I wanted  to do the job better just out that bin.
I'm not too proud to go Dumpster Diving, I feel clever for being able to get this perfectly good stuff for nothing not ashamed!

 
Quote
I have the luxury of not caring about size, weight. 

I built a setup years ago for wirelessly  sending pictures from a camera to a server 200+ M away.  At the time it cost thousands for the gear to do this and the range was far more limited.  I made it up using off the shelf every day components and some DIY antennas and the like. It was not compact, it wasn't pretty and it was a little involved just turning everything on in sequence and booting an old laptop BUT... it worked perfectly when about everyone I asked or discussed it with pretty much laughed at me and said I had no clue.
They were right, I didn't, never played with that before but It went from idea to reality in less than a week and I spend about $100 on the whole thing. Perhaps not having a clue was the best assett. I had no idea why it wouldn't work so it did.
I packaged it all up in a cheap suitcase I screwed wooden shelves into and mounted that on a trolley which also carried a battery to run the thing about a week and supported a small mast for the antenna I made to beam the signal back to our trailer.

Found it all the other day in the suitcase. Even today, to do what it does would still not be cheap , not do what this does and not have near the range.
The layout was clunky but the operation was fantastic.

If you can do things yourself, you are always better off than having to buy pre made I reckon.



Quote
I'll just have lots of screened vents on the box and let the heat sink help drive the thermally driven airflow.

You know my proclivity for forced air. I'd have a little fan blowing in the bottom of one corner and extracting out the top of the opposite. Nothing cools in my book like forced, moving air.  :laugh:

Is your shed well ventilated or well insulated to keep the heat out?

mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1283
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: DIY Low EMF 5 step Sine Inverter
« Reply #7 on: July 30, 2018, 06:05:52 AM »
My inverter logs my 1/2 hp Franklin well pump motor right at 1Kw.  Poor Power Factor on the motor is what kicks it up over 800w/hp

BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #8 on: July 30, 2018, 07:41:06 AM »
Good point on PF, Mike.  I've got to try adding some motor run caps and see if I can lower the power draw a bit or if Franklin already has it optimized.

I also thought about reducing power frequency and voltage a bit after it's started, but I'd need a faster and more capable (ram, faster ADC, priority interupts) controller processor as the little ATmega328P is tapped out. 

Franklin has a PV direct inverter for running their single phase pumps. About $3K and no doubt an EMI monster. But I was able to comb through their literature to find out what they are up to.  It slows down to 30Hz and reduced voltage if PV power drops.  They can go no lower than 30 Hz or their pump's hydrostatic bearings fail.   

 I don't need full power flow at all, it will just be topping off a 2400 gallon gravity feed storage tank on sunny days.  I expect their controller also replaces the standard motor control box so they can manage their own soft start on the start windings.  A bit more of a project than I wanted to handle right now.  With 3 of my soft switch H-bridge boards and a bigger, faster processor I could also do 3 phase MSW (3 step).  6 H-bridges for 5 step sine.

I did get my two 1000 watt transformers wrapped with 3/4" mylar strip tonight, and also wrapped my 14mH gapped, laminated toroidal choke.








BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #9 on: August 06, 2018, 09:35:38 PM »
I've got the inverter installed in the battery bank shed and am running my washing machine PV power using the remote start. Voltage and frequency are perfect.  Battery bank is holding in float at 139V thanks to the new 1500W array addition to my old 875W panel array.

It was a relatively uneventful installation but I had an interesting problem with the generator/inverter 230V switchover coil relay; it was chattering during the transformer soft start, even though voltage during the soft start is limited to single transformer, only 150V max.  The soft start failed as it was also connecting to remote step down transformers and blew the fuses.  I figured it out after some end to end testing.  I've temporarily bypassed the offending relay and tomorrow will add a time delay module on the coil so that it won't kick in until transformer soft start is complete and the the output has stabilized at 230V.

I still have some work to do; I haven't installed the earth grounding system for EMI filtering. Grounding the center tap of secondary side the two 1000W transformers completely eliminates the very low end of the AM band EMI. It's like adding a shield ground between the two sets of windings, which is what I'd probably do if I was having them custom made.  Since this is a low budget DIY project, I just rewound the secondaries of some stock Antek transformers.  They aren't ideal for this application since they buzz with the non-sine primary input, even with no load.  The laminated cores aren't adequately bonded for that. 










BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #10 on: August 08, 2018, 10:16:54 PM »
Light white smoke this AM (more distant fire) with no taste and less misery for me so I got up at 4AM and tried to get something done before the worst of the heat and smoke.

I did get the software updated with a slightly better version of RMS voltage sensing.  I added a second 65 sample half wave with 1/2 a sample time shift.  It's adequate now, +-1%. I can improve it more by exceeding the best accuracy speed of the ADC and doubling the sample rate but will wait until I have finished the grounding system as the little bit of common EMI on the AC now is likely affecting the RMS accuracy.  It's also only a 10 bit analog to digital converter (ADC) so that may be the limiting factor at this point.  Hot rodding the ADC may only make accuracy suffer further.

I topped up the water tank with about an hour of running at 1385 watts in 93F heat.  The transformers were barely warm, the heat sink on the 2 H-bridges was also barely warm.  No need for fans. 

I tried a new transformer soft start routine, with both transformers pulsed at the same time, in opposite polarity so that the net AC volts would be zero until soft start was almost complete.  Alas, it blew a 3A (gentle testing) fuse and I don't have enough 3A spares to continue with trying new variations to see what keeps the Antek transformers happy.  After I cool off for a bit I'll install the time delay controller on the output relay, and then I'll be able to switch between Listeroid 6/1 and inverter power from in my shop. The inverter gets priority- if it's on, it steals the 6 gauge twisted pair coming down the hill.

I'll do a video when we have a windless AM without too much smoke.




BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #11 on: August 11, 2018, 03:03:47 AM »
I got the earth grounding system put in over the last few days. That was a lot of dirty work. I did hook the transformer secondary "center" to ground, but still have to modify the H-bridge output filters to add capacitors to ground.  For all the bench work, I didn't have a decent ground so couldn't test that for effectiveness.

Got the 3A test fuses so back to the start up relay issue. 

Tried the ICM 102 delay on make controller- it is either defective for won't work for a 230V coil relay.  The spec sheet that came with it says 40ma minimum current...a detail left out in the sales literature.  It was just turning on immediately.  I took it down to my shop and tried it on generator 230V, with another Omron relay with 230V coil. Yep, that didn't work.  Coil is being fed 80VAC when "off".  ICM in Syracuse, NY,  blew this one.

I decided to have another go at a zero voltage output transformer soft start.  Why add hardware with some new  software can do it instead?  With keeping zero output voltage in mind, I wrote a new version pulsing one transformer positive while the second negative, then vice-versa, increasing the pulse width by 50usecs each time.  The transformers are the same, so outputs in opposite polarities in series cancel.  I carefully matched the pulse and delay timing of the old successful routine.  Voila, it worked on the first go.  Figures now that I had an open bag of 20- 3A fuses!  I can hear the distinctive buzz-winding down sound of the soft start, with zero volts on the meter, then snap, voltage goes to 230 and the output switch-over relay goes clack.  So I don't need the delay on make relay controller anymore. 

I put the covers on all the boxes yesterday and cleaned up the chaff on the shed floor.  Looks pretty decent. All that's left is the final EMI cleanup. 




glort

  • Hero Member
  • *****
  • Posts: 2327
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #12 on: August 11, 2018, 05:03:50 AM »

Sounds like it has come together Perfect Bruce.
You seem to have a similar thing to me with design.  Waiting on something then then get another Idea that works perfect and then have a lot of spare parts you were sweating on you now no longer need.

Unfortunately I have this other proclivity of trying to think something through for months and believe I have it right then 5 Min after it's don'e I think I should have done it another way which would have been more advantageous.

That's why I have a welder AND a plasma cutter.  One to put stuff together and the other to take it back apart so I can do it the way it should have been done in the first place!

Inverters while common are not an easy thing to do well. I can only how much more difficult putting something together with regards to the  low EMR as you have done would be.
I'll bet this would leave anything commercially available for dead.   Perhaps there is a market for your design with others with EMR concerns? Might be a profitable side line for you even if you just sell plans and schematics.

BruceM

  • Hero Member
  • *****
  • Posts: 2321
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #13 on: August 11, 2018, 06:07:31 AM »
Thanks, Glort.  Open sourcing this hardware and software and my 120VDC battery management hardware is one possibility.  I'm afraid most need a finished product, competent installation, and lots of support.  Precious few are well enough (or have the resources) to tackle living off grid after becoming ill.

Wish I could use a MIG welder and plasma torch.  Now I have to get back a few hundred feet from those. I wasn't too bad with a stick welder/cutting rod at one time.














« Last Edit: August 11, 2018, 06:23:59 AM by BruceM »

glort

  • Hero Member
  • *****
  • Posts: 2327
    • View Profile
Re: DIY Low EMF 5 step Sine Inverter
« Reply #14 on: August 11, 2018, 09:49:34 AM »

I often think of you Bruce when I'm doing things and i'm sure can only part imagine how difficult things must be for you. The bit I can imagine makes me realise how entirely different my life would have to be if I had the same hurdles you do. Your ailments would have long ago taken many others without your skills, learning capacity and guts to adapt and overcome.  I know I wouldn't have a hope of doing a fraction of what you have.

I did a LOT of welding this last few days and I feel better than I have in a couple of weeks actually although sore and aching from doing too much at once like normal. I guess I don't have any EMF sensitivity , YET, but in this day and age, who knows what will get you first.
Pretty sure my Diabetes has not been good of late and that's one of my main ailments. Then again, last time I thought it was that I was OK and the doc said it was my depression that was the trouble.  I don't know how a mental state makes your back ache and so tired you want to fall asleep all the time so I'm still only half convinced.  Going back on Monday so see what the blood tests say this time. Nothing good i'm sure.

So many things these days people suffer these days. I have to count myself lucky that at least I can be treated for what I have. You are pretty much on your own and to survive, endure and overcome as you have,  that takes real balls and guts in my book and you certainly have my admiration for that and a lot of other things.