New no battery pure sine wave solar power system with smart switchers.

[GridWorks Green Solar]

Good morning, up at 5AM in preparation for another dual 140VDC solar test on the two FET inverter.

What is different this time around is the project system has been powered down so I can fully access and test the 10amp ISO transformer output from the new two FET inverter. Hopefully the inverter will push the level one quartz tube heater and lamp directly off the built-in outlets on the front of the ISO transformer.

Each solar input is fused at 5amps seven series panels 140VDC and the ISO transformer is fused at 10Amps, Previous low voltage testing says this might just work.

Wish me luck, expect full sun this morning for a short time, running the best sinewave output from the inverter to the ISO transformer hoping for a home run running loads and pure sine output off the transformer.

If this test is successful next stop is dual 160VDC eight series panels each input testing.

Will post more today as testing continues, If successful more information and photos will be posted.

Have a set of fixed resistors 20.5K and 39.1K for the inverter but not going to use till later using 50K potentiometer so I can make small adjustments to the output.

More very soon

 

[GridWorks Green Solar]

Mixed results from testing:

ISO transformer runs much quieter but only transferring approximately 50% of the input power, your best bet right now is to run loads directly from the two FET inverter.

Once full sun is on the panels the inverter runs stable but if you add the ISO transformer the power output wavers a bit in 3 second intervals.

During low loads on the inverters output voltage is a bit high leading me to believe dual 140VDC is the correct input voltage for the new two FET inverter.

Everything seemed to work OK but best results were when the inverter was directly pushing the loads.

The Project Systems pure sine output is superior in pushing the ISO transformers. (Recommended).

I don't really understand everything that was going on during this test but the inverter has not been damaged by all the things I have tried, Have repeatedly stopped and started the inverter with and without the ISO transformer with no damage done.

Don't know if it will help ran into a YT video that had a small LC circuit directly connected to the 555timer turning the square wave into sine, wonders what happens if I use this as a FET trigger



More later

 

[GridWorks Green Solar]

Made a decision to return the Project system to the 5+5+5=15 amp 180VDC configuration for the summer

I will make new diagrams and parts list for what is working now, I invite you and others to build,use and improve upon the two FET inverter designs.

Work will start on a two side Printed Circuit Board (PCB) for the 2 FET inverter, only mystery is the pure sine choke value in MH for the LC circuit, any help in testing this part for value ?

New inverter will be the same size as the project power board in the long direction for easy case mounting or heat sinks.

Project system restored to normal, Picture, Only need one more change in the rooftop solar panel wiring to be finished for the day.

Taking a break for now, best wishes

 

[GridWorks Green Solar]

Inverter runs smooth in this low drive mode have not lost a Mosfet/FET since heading down this path. Avoid any spikes on the oscilloscope inverter output.

Literally go from zero output to FET starting then adjustment for a sweet spot just a notch higher. Power is not as clean as the project power system but have found it to be useful for lighting,small heat, small electronics and wound motors. Low heat generation from the FETs.

Keep the voltage above 100VAC and the new two FET inverter just keeps going.

Additional information in some of the previous posts. This inverter will translate into a small circuit board that will fit in your hand, Groups 7 standard 12VDC solar panels, Minimum B1 7 panels B2 reverse 7 panels, Need more amperage parallel 140VDC sets B1 (7) and (7), B2 (7) and (7) and so on.



More soon

 

[GridWorks Green Solar]

Note worthy things about the new two FET inverter.

Low heat generation from the FETs suggests energy efficient operation.

Interesting response to a surge condition at first (first second) it looks like the inverter may fault but it just keeps pushing more and more watts into the situation. Was worried about needing a soft start but the unit builds behind a start up load nicely, most watts I have seen to date is 650 for the two FET inverter.

Stable 59.5 to 60.4 Hz operation good sine wave and easy adjustment to 50Hz if needed.

Operation at the best sinewave low end operation of the two FET inverter has resulted in no MOSFETs failures in the past three live solar panel testing at dual 140VDC and 180VDC.

Simple design and with terminal strip for the FETs mount and connections you can change out parts in minutes if ever needed.

If your into electronics give it a try have had loads of fun building this inverter, Like lighting up twin jet engines one forward and one reverse since both are synced 120VAC 60Hz power is extracted efficiecently from the process.

Best wishes

 

[GridWorks Green Solar]

Just an early attempt at a printed circuit board lay out all wires that jump another wire go to the bottom layer of the circuit board traces.

Next attempt will be to get the 555timer, optic couplers and floating power supplies area accurate and spaced.

Accurate drawings and parts list soon, this is just a doodle but considering actual physical parts lay out and size.
Need to add the additional support components around the FETs.

First draft. 50K potentiometers belong on the optic couplers input not the gate triggers, fix it next go around.

On a second thought testing two 25K potentiometers in that location has never been tested yet

More soon

 

[GridWorks Green Solar]

Currently working on parts list and diagrams/printed circuit board for the two FET inverter. Just a couple more days to complete the drawings.

The LC for a 555 timer to turn the square wave into sine is 288 uH choke with a 10 uF (works) to 24 uF capacitor (calculated). Have photo examples of the 1000watt and larger 2,000 watt chokes in several previous post.

Going to use my 60Hz 555 timer dual output optic driver circuit to drive a four N channel FET single DC input inverter of my own take of the project power board, If I can get the 555timer to work via a 12VDC floating power source it may not even need the optic couplers.

Planning to use an online PCB card maker initial order of 20 - 30 circuit boards. 6 1/2" wide by 2 3/4" tall.

Another pre draft of the printed circuit board layout

More later

 

[GridWorks Green Solar]

How about the correct parts list for the new two FET inverter.

Brain cells were abused in the production of this list, alot of forward thinking and cost reduction thoughts went into this choice of parts.

Money goes into the output FETs for serious power production P FET is tough as nails and the 40N65 FET has a proven track record.

Ask questions if you need assistance, one more day on the main circuit drawing.

Best wishes

Added DC input capacitors to the list.

 

[GridWorks Green Solar]

Main drawing now passes first audit, Need to redraw at least one more time before it is published caught missing input capacitors on the parts list during audit.

Killed two or three birds with one stone by just organizing part location and direction. After rotating things a bit the whole inverter became more simple this will help in making a circuit board also.

More soon

 

[GridWorks Green Solar]

Here it is moved potentiometers around and simplify a few things, Official circuit design of the new two FET inverter.

800 ohm resistors are optional protection for the optic couplers from too high of a setting, set all potentiometers for increasing value in the clockwise direction, (Start all potentiometers at a minimum setting) ( First test dual 9 VDC on inputs nothing can be damaged and you can see/adjust everything.) Passing the dual 21VDC bench test or higher means the unit will likley tolerate 140VDC dual solar input, This a early release of Version 1.0 of the new two FET inverter, expect refinement and a nice circuit board soon to mount the components in kit form, Two FET inverter will be compact and versatile.

Use a 25 watt standard light bulb or equivalent as minimum load on the inverter 24/7. Stability issue.

Expect more improvements highest output so far 650 watts 120 VAC 60Hz 550 watts was long-term tested.

Enjoy and ask questions if needed.after connecting the capacitors to higher voltage you must follow discharge procedures before servicing the unit!

I am going to improve the circuit diagram and audit it again, If I have a mistake the time to catch it is now.

Have plenty of alligator clip jumpers available will do a physical recreation of the optocoupler to FET output per the Official design on the second test inverter to complete the audit and report back to everyone Have plenty of new parts to test.

More soon