diy solar

diy solar

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

Large Mosfets have arrived must mount the largest FETs to the heat sink and test.

The P channel 40amp FET is the largest I have ever owned.

The small ones were recommended by the diagram wrong voltage range 100 volt maximum, the two larger ones exceed the specified needs and is what I recommend if you want to produce full time 120Volts 50/60Hz or 220Volt 50/60 Hz (not tested yet).

A few bumps in the road but good progress going on with the new two FET inverter, first one being not grounded or ISO transformer isolated in testing, The second will be grounded per the diagram and I pray it works long term, could reduce the complexity/cost of turning sun into usable power.

I think this is a solid step forward I invite some young electronics guru to run with this idea, The 50% duty cycle on the alternating solar arrays will spike the voltage 50% of time if you use the correct capacitors and diodes to trap that energy for the the inverter you will have big power to turn motors/heaters and so on.

More soon
 

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Tested a capacitor from a radio parts board and got 73.2 Hz good square wave from the 555 timer, adjustable capacitors for the 60Hz win.

Second picture Another capacitor from the same parts radio, Now running 61Hz on the 555 timer very good! Small green capacitor clearly marked 2A154K and 100K potentiometer using the simple 555 configuration. Trash spots in the square wave is due to long alligator clip leads and twisted connections once I get it just right everything will be soldered and reduced to minimum lengths.

Baby steps forward.

Keep it simple is working!

More soon
 

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New Mosfets mounted to heat sink, All parts test good have full manual control of both P & N FET channels, It is another great day when I get what was paid for.

Making progress on all fronts.

More soon
 

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Early look at the new Prototype two MOSFET flip inverter, lots more to do.

Going to double glass fuse at 10Amps until I fully understand how this is going to function safety first expect final DC maximum input voltage between 150VDC and 180VDC FETs are rated 500volts 20+ Amps. If it works as expected,

Found another something I don't like about the original plan pin 3 out from the 555 timer connected to two inverted diodes and directly to the FET gates. Seems a single resistor to get the output into the best range and let it feed the Hi tech MOSFETs gates for switching.

Cleaning out my work space and getting off the dining room table with this remaining project.



See you soon 😊
 

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Here is a drawing of what I plan to build the actual connection to earth ground will omitted on the first go around, this shows the new 555 timer configuration and complete system overview.

Full parts list soon.

Decided to build the prototype in top part of the combo inverter case, This will save me hours of work later on and if it works correctly will allow faster real world testing.

Actually a simple design. Not yet tested. Best wishes

More soon
 

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New home for the two FET inverter, much better idea, more caps, better layout. Ruff drawing passes general function audit needs fuses and Zener diode is 5.1 volt.

Adjustable capacitors due in tomorrow.
Update: Third picture adjustable capacitors are here already know from YT videos the light gray/white ones work best with the 555 timer.

Will start tomorrow with 555 timer final adjustments and soldering.
Soldering on long conductors to the different parts that need connected.

More soon
 

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Have made real forward progress with the dual DC inputs soldering, mounting parts and boost capacitors.

555 timer is not steady enough for power production floats between 58Hz and 62Hz the LC circuit needs 60Hz to work properly, going to try another method.

I am starting to doubt that the original circuit diagram was actually functional but stick around we are going to fix it properly.

Need 60Hz square wave signal to make the FETs work properly,

Going to test the 555 timer for it's ability to switch the FETs before moving on to something else.

More soon
 
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Parts list:
R4 & R5 100 ohm
R3 10K 10 watt omit resistor 555 timer needs 5VDC separate power supply
D1 & D2 1N4148 diode
D3 & D4 15 amp 200 volt
C1 & C2 200volt+ large boost capacitors, testing will show exact Mfd!

555 timer simple configuration
1H104K capacitor, 500K potentiometer drawing shows 100K the 500K is better.

Omit part Zener diode 5.1 volt (Actually needs good 5VDC power supply for the 555 timer)
P channel Mosfet IXTK40P50P
N channel Mosfet IRFP460

You will need two FET gate isolation transformers for high voltage switching, new circuit diagram when I get it working.

Parts may change as testing continues.
First version will be limited/fused at 10Amps blocking diodes will also be 10Amps rated.

Stable 555 timer at 61Hz for testing Mosfet switching and output. Best so far drift is between 60Hz & 61Hz. Moving drift to 59Hz to 60Hz for better match LC filter circuit (Major Win here!)

Last real hurtle is the FET gate isolation transformers for another win.

Third picture raw output from the project power board before the LC circuit I have high hopes this is going to work well.
Did not lock on to 60Hz signal but clearly a square wave output MILs requested test of the project system FETs output, convinced me to build a two FET inverter that will actually do the job I will keep at it till its right. Single high quality FET switches can pass alot of energy, with the 50% duty cycle the capacitors will be fully charged when the switch closes on the next output cycle, In technical terms its known as attack and in the real world result it means this inverter will push a motor well.

The inverter is coming in at around $200 in parts and is really not that complicated to build.

This post updated when build changes are made.

Best wishes
 

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Using clear silicone caulk to glue and insulate the individual parts into the half inverter case, only thing left is to finish and install is the 555 timer, next will be an intensive session of soldering to complete the inverter.

Going to test with and without an ISO output transformer. Oscilloscope pictures of each hope to get good pure sine from each.

Basic concept already works on the test bench just need good MOSFET gate trigger and 60Hz signal for a win.

All the components glued in place, lots of soldering ahead to complete the two FET inverter.

My main target is 120VAC 15Amp 60Hz pure sine goodness.

More soon
 
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Getting close to electrical testing, Most everything is glued and mounted upside down 555 timer encased in a blob of silicone a bit ugly but it is also a prototype, passed basic wiring audit.

First test will be 9 volt on all inputs, second test 21 volt on all inputs.

Adjustment knob is for frequency 60Hz. Relocated FETs to the center of the inverter.

Safety first.

More soon
 

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555 timer is not steady enough for power production floats between 58Hz and 62Hz the LC circuit needs 60Hz to work properly, going to try another method.
Get a 3KHz oscillator, divide by 10 and divide by 5 with 7490-type counters.

Alternatively get something like a PIC processor, almost any crystal, and divide it down to the frequency you want.
 
Get a 3KHz oscillator, divide by 10 and divide by 5 with 7490-type counters.

Alternatively get something like a PIC processor, almost any crystal, and divide it down to the frequency you want.
Thanks may need something else with better clock, First 9 volt test the oscilloscope is watching inverter output with no iso transformer, small load on the output.
Results 11Hz output and right now it will not respond to the adjustment knob but the good news is that bold clean sine wave.

Get it up to 60Hz and it will round out nicely (Third base😀)

More soon
 

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21 volt test inverter worked for two seconds 25 watt bulb lit brightly and failed, no 555 timer signal anymore. New 500K potentiometer but unit went down so quickly I didn't get to test.

Figure need new 555 and better voltage regulator to fix the issue, excited it may have been two seconds but it works.

Taking a break now, more later.

Can not turn back now even though it was only a few seconds it worked, Can’t tell you how many times the project system through me a curve ball after showing me that it actually works, two steps forward and one step back.

Will soon master this inverter.

Best wishes
 
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Have restored the 555 timer by replacing it with a new one, Watched several videos on making the timer chip more stable, one recommended improvement is to add a capacitor to the Vcc + and - of the timer.

Learning about how to bias the FETs so the gate trigger functions properly.

Restoring everything back to the 9 VDC test conditions for more testing,
Don't mind a separate power 5VDC power supply for the 555 timer as long as the FET triggers work correctly.

Just encased the new 555 timer in epoxy and will slowly resume testing.

Don't think the 5.1volt zener diode and 10K 10watt resistor work at higher voltages to protect the timer the one from the 21VDC test was cooked.

Baby steps till I figure it out.

Best wishes
 
Small step forward, oscilloscope monitoring FET gate trigger signal at the FETs, steady 60Hz, put timer on it's own battery while leaving it also connected to the inverter, Problem now lost FET output, not responding to the nice trigger signal.

Blue dotted line is center.

Removed third battery for timer attempted to run it normal no 555 output and 5.1 zener diode was running way hot to the touch, NE555 has 18 volt limit maximum I have some real nice heavy-duty 12VDC Zener diodes.

Should be no way to damage anything with 9VDC batteries, If the zener diode was damaged it was during the 21VDC test.

Working on it, more soon
 

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Have no doubt with an EGS002, DY002-2 or grid frequency op-amp I will be able to eventually control the FETs.

Something changed during the 21VDC test and I can't seem to get it working right now, new parts most of the way but Something still a miss.

A small 120 volt AC transformer powered from grid with an output center tapped at +5 to center tapp and minus 5 volts should be able to directly drive the gate fets may require two diodes to get it right.

May start testing on the lesser expensive parts (MOSFETs) till I make some progress, More later
 
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About to go out of town for a few days, have electrically tested the DC inputs and big FETs for manual control and they all passed.

Back to a no signal from the 555 timer, had full FET switching control earlier but something has changed will work it out when I return still have 5 new 555 timers and a better understanding of how the circuit works during the 21VDC test the input to the power circuit to the 555 timer was 42VDC. 25 watt bulb lit brightly for 2 or 3 seconds before the 555 timer burned out.

Max voltage on the 555 is 18 volts nothing I have done recently with 9 volt batteries should have damaged the timer, but somehow I managed to do so probably a bias issues with the FETs.

Have proven at least to myself the original circuit diagram likely never functioned properly especially at 220VAC output!

With a 8.75 VDC test voltage into the FETs getting 8.64 volts out in manual on/off gate trigger operation. Excellent.

Have a idea to split the FET gates with one diode each and test individually the operation with the correct diode should block any back flow bias between the two FETs and timer. Also give the gate a slight bias to turn off.

More later
 
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Finally found an example of a 5VDC circuit that controls a 500VDC N channel Mosfet, uses what is known as a gate driver transformer.

Works just like a isolation transformer/ISO for the FET gates will need two of them to fix my current problem. Also may require two diodes.

Will build a test circuit out of smaller FETs till I achieve a working example.

As with the project power system needs Iso transformers to block the bias between the different power sources.

Will likely order 4 of the small transformers, Awesome.

Pictures are examples of the transformers and drawing is similar to what I hope to accomplish.

More later
 

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Back home safe from Florida and spring break traffic, Need 1 to 1 isolation transformers for FET driver circuit cost about $35 for each transformer. Found a free set of 10 to 1 on junk inverter boards I own.

Going to experiment with the used ISO transformers, cheap N and P channel MOSFETS, Also the 555 timer for 60Hz signal. Once I get something working in the 100VDC range. Easy upscale to get this circuit working correctly at 150 to 180VDC.

Shutting down both systems for maintenance, old system has flooded batteries a real job to do correctly, they need maintenance for summer, Harsh conditions are on the way and the maintenance must be done, during the last watering two batteries had the top of the plates exposed, New system running great but I see an opportunity to improve several critical connections, Great big antique soldering iron makes superior connections to the big wires and circuit boards.

Getting ready to harvest a lot of sun this year.

More soon
 

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Project system back up and running with improved DC connections, Project system working perfectly and suddenly more of the power boards you need are available on Ebay.

Highly recommend the 2,000 watt boards.

Kits around $40 factory boards around $60.

More soon.
 
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