diy solar

diy solar

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

OK burned brain cells on this one, based on 220Volt DC voltage regulator circuit.

The sources are directly connected instead of the drains for output, this will allow me better bias and gate control of the FETs going to test this configuration but totally unknown if it will work.

GC is gate close by default, not sure of the value of this resistor 10K to 50k should work, looks promising.

On second thought I should start around 600K for the gate close resistors and test lower as not to over drive in the reverse gate close direction.

Low voltage testing to begin later today.
(This approach just doesn't work but big steps forward with plan B)

Test results:
(Failed FETs failed to function attempting reverse to source to output) maybe the FETs I am using don't support that configuration.

More soon


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Darn Postal service drove past my home three times today and as they departed the road I live on the opto couplers order went to delayed.

Going to prewire and start the qualify process on the totally new configuration.

Everything seems to be progressing forward. Have a plan B configuration but it has only been tested to 100 volts DC.

More soon
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Still don't have the opto couplers but you can disregard all previous two FET diagrams. They don't work this one does.

Previous diagram failed to control the output gate stayed on continuously.

This is operational at 9VDC have the default to off I need and fast trigger control of both FETs correct trigger bias on the Mosfets. Have full control of both channels in real time.

Some version of this will become the new two FET inverter.

More soon


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Opto couplers are here successfully sending signal from 555timer to coupler and receiving modulated output from the device, a whole lot like a 555timer in size.

Lots of soldering to do, more steps forward. Successful in preparing 2 of the opto couplers for service with resistors and short wires, glued down to base with silicone caulk, done for today.

Best wishes

Seriously think I see a solution but several more days testing ahead, the real trick now is to keep it stable while increasing the operating voltage, tuning the led brightness in the opto couplers will be tricky Max power VS shorting out the FETs due overlap in dual phases. Thank goodness I have a good oscilloscope (From ghost busters "Don't cross the streams")

More soon 😀
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Giant step forward, now driving Dual optical couplers correctly phased from a 555timer, was not easy but got it working.

This will absolutely work and may be applicable to other inverter types.

Lots of soldering ahead, Fantastic.

Lowered to 10Hz and you can easily see the test leds are flashing like rail road lights back/forth or flip/flop, don't expect much trouble getting this to work on the Mosfets.

Despite what my eyes thought they saw the oscilloscope says I have two inverted drive signals that are 100% in sync, in other words it's a short circuit every cycle, Going to set the 555timer to the side and go back to the small transformers. Previously had the correct sine signals from the transformers.

So close more baby steps till I get the correct response from the optical triggers. Clawing my way back to the best trigger signal so far, This time around I have the opto couplers.

Brightness potentiometers for the LED in each optical coupler will allow adjustment of the center part blue/yellow over lap.

Taking a break, more soon

Have 60Hz signal to optical couplers and can see the output on the ohm meter and scope, even with examples have yet to trigger the FETs properly, more YT videos and education is needed.

555timer circuit is excellent just need a transistor circuit to flip the logic for a second signal to the other FET.

More soon


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First successful trigger of a N channel Mosfet with the opto coupler device, single channel output directly from the FET looks good.

Perfect 60cycle signal from small grid powered transformers, more work later on with the 555timer.

More soon

Only 9 volts testing till more progress is made. Best wishes.

Second Picture this diagram is responsible for today's steps forward.

See the +50 to 90 voltage range,I must make it function at 180VDC or a bit less for a the win.

Excited starting out the brightness of the LEDs is just above the half way mark.

Notice the top of the sine wave no LC circuit during this test, advanced Mosfet is tracking the wave nicely.

Learning a ton here the reson a single FET inverter is a bad idea is the energy in the bottom part of the wave is an illusion, LC circuit exposed it.
Made the right choice going with two FETs dual power.

More soon


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Proof of P channel optic coupler Mosfet control 60Hz not as sweet as N channel but working.

Photo diagram of the P channel Mosfet test from the 60Hz opto coupler.

Time to start increasing the DC voltage.

More soon 😀


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The cheat for what I am attempting to do is use two independent 9 volt batteries for the gate power source on each FET, The battery will provide isolated power and allow the full FET voltage need 180VDC control on the 500 volt rated Mosfets.

To be self powered must make a 180VDC to 12 volt DC down converter X 2 one for each FET. It must be correct or mayhem will ensues (Blown FETs or short), I have several examples that ues high ohm 5 watt resistors and 12volt zener diode.

Will soon with alot of soldering and improvements be able to test full voltage and full power on the big two FET inverter, will work till the 9 volt batteries run down.

More soon 😀
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Going to build and test this should allow full volts/amps on the FETs, two big FET separate experiments combined.

I would down load this diagram if I were you, testing say I am close to full function.

Another day of soldering and the testing will get real serious real fast.

Just like the doorbell transformer 16VAC is isolation for the CPU on the project system, all I need is a 12VDC isolated power supply to ditch the 9 volt test battery.

The earth ground connection has not been tested, the project system would not survive if earth ground was connected in that manner (The FETs would short out) Big plans to test after the inverter works, test at your own risk if it servives being grounded it could make things less complicated to turn sun into 60Hz 50Hz power.

Have a fresh set of big P & N Mosfets mounted to heat sinks, Getting ready to rumble.

This did not work as expected not sure exactly why 9volt batteries failed to provide gate switching suspect a bias from having the output drains connected. The two FET inverter lives just wait till I get 12VDC isolated powered gates and full input DC voltage from the FETs.

More soon


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Stereo sine output 😀

Still 9volt testing but that is a two channel output from the P and N MOSFETs. The drains are bonded together.

Not as pretty as I wanted but a almost home run!

Give me a bit more time, For a really simple circuit it makes my head spin at times.

Major step forward today new two FET inverter is alive and kicking, work will progress in raising the operating voltage.

The green and yellow going through the the pure sine choke is the P & N drains both feeding the input of the pure sine choke.

Using small grid powered transformers to feed 60Hz signals to the optic couplers set to 60% output on the LEDs in the opto couplers, output from the optic coupler triggers the gate, a 20K resistor keeps the gate closed when the signal is low.

Extra testing revealed very low or no timing error between the two phases, everything is in sync. One of the main objectives😍
Center line on the scope is the dotted line above the yellow line, both look equal in power production.

Last picture past 18VDC test output blub is glowing ✨

Ordering block 5watt resistors for internal power supply 12VDC to the gate FETs.

Missing input capacitors and larger loads will smooth the output sine, 50% duty cycle is making regular pattern in lower output sine. Running the largest FETs in this testing.

More soon 💡


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Always was the plan to build two inverters, next few steps will be to use all new parts to get the big metal inverter up to the 18volt test level and design spec I currently have working, the capacitors and diodes on the dual inputs should help smooth the output, big inverter has a 2000 watt LC circuit.

Current test inverter will be used for 180VDC to 12VDC gate power supply when parts arrive or figure something out.

Got to build up two more optic couplers for use on the big inverter and get the inverter working with dual 18VDC power supplies, Test it and start tweaks for better sine wave running the output though an ISO transformer was always part of the plan for rounding the sine wave output and provide FET failure safety.

More soon 😀
The two 9 volt batteries for gate trigger power operation did not work as expected, once I started to experience problems I decided to eliminate the 9 volts and hook up self powered (Max voltage 21VDC on the FET gates) have a 5watt resistor,12 volt zener diode, 20mfd capacitor power supply circuit that goes along with the current build, proper gate power supply will allow full voltage from the FETs, all I need is 180VDC from a 500 volt capable FETs.

This diagram most closely describes what I will be working on, the 5 watt resistor next to the zener will rise in value to match the 180VDC input voltage, I will use ohms law to compute the correct resistor with a maximum of 150 miliamps 180VDC, will need one for each FET, possibly one more to power the 555timer.

Excited, taking a break now, more soon


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Just a reminder last night it was in the upper 20 degrees Fahrenheit range today the project power system is running everything including high heat in the living room.Tuff as nails if assembled properly.😀

Soon to be running the 120VAC mini split for summer comfort, no need for expensive batteries when you can just burn the energy and ditch the maintenance/expenses they inevitabley bring.

Work in progress more soldering on the big two FET inverter today. Electrically tested and mounted the two opto couplers in the inverter case.

More testing ahead.


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Made the dual 120VAC to 6.4VAC/11.4VAC transformers,Potentiometers, Diodes, for dual 60Hz signals to the optic couplers into a portable separate unit that can easily be move between the test inverters. Will purchase new parts the moment one of these two FET inverters push a motor or heater properly.

Really excited testing reveals similar power transfer to the project power board at 18VDC, close very close.

Within a couple hours of retesting the big two FET inverter for 9 and 18VDC operation, taking a break right now before connecting the optic couplers to the FETs. Have paid close attention to setting the optic couplers at 60% brightness confirmed output is as close to 50/50 I can get.

More soon
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Big two FET inverter is only working on the N channel right now, will tackle P channel tomorrow, look how nice the wave form is from the capacitors and diodes, LC output circuit.

Another situation where I have already had it working, not quitting now, will document how I stomped this elusive bug for the second time.😀

Could be 60Hz signal is too low or bias issue with the trigger signal. No output from the P FET on the drain right now.

More soon


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Big two FET inverter is working😀

Problem was leads to P gate resistors were reversed, currently testing at 18VDC, wiring diagrams mostly correct.

Looking good but room for improvement in sine wave timing. Adjustment potentiometers 100K are critical for the optic couplers LED brightness and will be experimenting with small capacitors to change the timing a bit and expand the wave form. Start brightness below 50%. Second Picture: best sine wave I could get with current adjustments.

Third picture:
Test bulb glowing, was overdriveing optocouples but things are now better sine wave is pretty clean❤️

Next big steps is internal 12VDC power supplies for the gate triggers and voltage increase till 120VAC output.

More improvements and testing soon.

That is two prototypes in a row I have working, solid plans to finish the inverters, can not wait for high voltage testing.✨

Waiting on 5watt block resistors to make 12VDC power supplies.

Will not claim victory till 120VAC output and heater/motor test is passed

Thank you forum member MIL for posting the original circuit, just could not get the dual FET dual solar array out of my head, I feel it has big advantages and a whole lot less complicated than a ordinary inverter.


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Working to solder in parts and wires to replace the alligator clip jumpers.

Like I said before the sine wave looks clean, only small adjustments to be made. Small capacitors can speed up or delay each phase.

All testing so far has not included the ISO transformer but that is about to change.

Parts ordered for floating 12VDC power supply. Second Picture example of project system output the gold standard sine wave I hope to mimic with the new Inverters. Running FETs output through a ISO transformer rounds the wave.

More soon


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Have a problem that has yet to be solved, Here is what I am thinking about and going to test today.

The P and N FETs are separate except the drains are bonded together and the neutrals (Must B1+ and B2- for ground or neutral) after I power down or change the drive settings on one channel or the other the unit malfunctions or works differently than expected 🤔

First I saw a YouTube video that suggested diodes to protect the FETs from inductive load spikes from motors, over night I came up with the idea of a single diode between the two FET drains to separate electrically the two opposite charged circuits, Have seen videos that say the P channel won't have as much punch as the N channel so the diode will be placed to block reverse current to the N channel FET.

May also need a single diode as well for the neutrals.

I will keep you updated 😀

More soon

Forget cost for a moment and consider this totally separate P and N mosfet circuits (60 Hz sync with optic couplers) each driving a ISO transformer and blend the ISO outputs back to full phase with proper ground/neutral 120VAC power. 💡 Think I know what my next big step is acquiring two ISO transformers but first test the transmission of single FET output through a ISO transformer is critical.
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Working now to totally make big two FET inverter P and N channels totally separate and electrically isolated from each other have already cut every every interconnect wire and added a second LC pure sine circuit 1,000 watt to the P channel, Don't know exactly how this is going to work but be assured it is going to be tested soon.

Any future interconnect between the two sides will be full tested for impact to operation.

Going to win this and learn something in the process.

Getting ready to grid power test inverters for hours and days at a time, going to get real familiar with how these circuits work.

On to something big here if the ISO transformer allows it!
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Separation successfully accomplished, N channel Mosfet had to be replaced for a non responsive gate, Although the bulbs are dim they confirm independent operation and output control, getting ready to run long term.

First batch of block resistors have arrived for the 12VDC gate power supplies.

Being an inventor is not easy invested about 5 hours today, replaced bad potentiometer, bad N channel Mosfet, LC circuit for P channel and corrected several wiring changes.

Only thing that is shared is the negative aka neutral someday could be earth ground connection, need more time but think I solved many issues today by insisting the N and P channels be as isolated/independent as can be.

Dual trace scope looking at N and P channels output Second Picture

More soon

Now able to run the big inverter 24/7 from grid power, tomorrow work on two of the 12VDC power supplies.


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