PowerJack 48-volt 16000Watt AMG version LF SP PSW inverter

It is also certain that PJ will be switching to a Taiwanese-made processor within the next few months due to the severe supply chain shortages facing pretty much all U.S.-made chips.

Many Chinese from Taiwan get special treatment in mainland China and in the USA .    

15 hours ago, Sid Genetry Solar said:

Ruichips (of RUH1H150R FET) is in Shenzhen, China.  NCEPower (NCEP039N10 FET) is in Anhui, China.

i believe the internet indicated there was a shut down in Shenzhen due to Covid virus and all work stopped for 30 days or more disrupting any work..

Regardless, the ONLY parts that I really can't procure (out of stock worldwide), are U.S.-made parts.  Chinese-made parts are in quite ready supply--and have been all along.

16 hours ago, Sid Genetry Solar said:

NCEPower (NCEP039N10 FET) is in Anhui, China.

i looked up the spec sheet for this mosfet....it is interesting and and lot of details to try to interpret...

the mosfets are used to change the DC current to an AC current which is then sent through the transformer to get the 120 or 240 volts out put.... it indicated they (mosfets)can operate up to 175 degrees C... that is hot for sure....that is the reason for the aluminum heat sink to get rid of the mosfet's heat generation...

what is the transformer going from 48- 56 volts or so up to 120 or 240 volts AC depending on the point of connection on the secondary windings of the toroidal transformer. on a 48-volt PowerJack inverter....so an AC step up transformer that has enamel coated aluminum wire for its windings... in a nut shell .... 

I am sure there are other parts for the transformation to make the sine wave from dc to ac.... all so very interesting, to learn a bit more about the LF PSW conversion process...

I do not totally understand all of it by any means, but still trying to learn,,, so thanks for a bit of direction....😎

the mosfet show up online as 5 cents to 1 dollar or so for each one. i am sure there is some little processor that controls their turning on and off to change it to the sine wave for AC... that is likely the part that is in shortage correct ( the microprocessor part to control the mosfet..) ???

of course i am not ordering any of these small parts,,, just learning/trying to understand....more

I do wonder though if adding the red blob filter capacitors on L2 would benefit the PowerJack LF PSW SP inverters as I have often seen commenters note that it is not filtered on L2 ????

thanks for the guidance....🤔👍😎

have study more!!! thanks a bunch!!! The sun is shining____ yeah

They aren't $0.05, that's for sure.  "Alibaba"-style prices are generally completely meaningless--you get an actual price when you contact the seller and ask for a quote.

Going rate as of now is ~$0.75/ea.

Yes, and yes.  On the current PJ inverters, it's a Microchip PIC18 MCU.

The specific methodology used in most LF inverters is known as "SPWM".  In short, "sinusoidal pulse width modulation" is a way of approximating a sine wave by varying the pulse widths of a specified carrier frequency in the shape of a sine wave.  In the PJ inverters, this carrier frequency is ~24KHz @ 60Hz (purposely beyond human hearing).  In other words, the FETs are running at a base frequency of 24KHz.  This carrier gets filtered out by the "red" polyester AC filter caps on the output of the transformer--and if said caps are missing, you get a lot of the 24KHz carrier on the output AC.

A basic inverter does NOT require a significant amount of components.  In short basis, the 4 SPWM outputs from the CPU must go through a FET driver (sorta the "LF Driver board"), and then directly to the FETs.  All of the remaining required support circuitry is CPU feedback and power supply.

The 175C rating is an "absolute maximum" rating.  Said ratings are classed such that if ANY of them are exceeded, instant failure of the device is almost guaranteed.  Note that the "Power De-rating" chart in the datasheet shows the maximum wattage @ 175C is 0W, i.e. no power.   (In other words, if you manually heated the heatsink up to 175C, the FETs would likely fail with a very small load on the inverter.)  Just because they won't be damaged at 175C, doesn't mean they can do any work at 175C.

In a SPWM-style situation (i.e. non-linear), they should NOT be getting hot.  Generally speaking, you don't want electronics to run hot--stuff goes south pretty quick.

... and if anyone wants some extra viewing on the subject of how quickly transistors die when used outside their rating envelope, check the JohnAudioTech youtube channel.  He designs various class amplifier circuits and goes into the nitty gritty of it all occasionally accidentally killing transistors.

SuperRobkar was able to get his PowerJack12000 watt PSW SP LF AMG version inverter to function on his ac 120v by improving the connection to the battery, but i do not know what the surge draw was yet..

Update: I was able to get the window ac to start. I decided to buy some Anderson sb175 connectors,and set PJ up for 120v only, and when connected to the battery bank, it worked!!

so there is hope after all...😎

hope you can forgive any typos in the previous post,,,it looked somewhat like a stumble upon nonsense afterwards a bit....🤣🤣but too late to change out any wording...

I need to be able to control the PowerJack's on/off switch with an opto-isolator or something to protect the batteries from over discharge in a more fool-proof automated system. perhaps I will have to rob one (temporarily borrow or repurpose one) out of another inverter until I can get the wiring figured out correctly!!

they all seem to use the 3 way style with a "powersav" thing that has no functional value for my use. it would be better as a simple on/off switch in my setup...i need some spade connectors of the correct size to test with it without permanently ruining it.... maybe an alligator set of leads might do the testing???

Time to see how the critters are doing outside....

thanks Sid, for more explanations....👍

SuperRobkar was able to get his PowerJack12000 watt PSW SP LF AMG version inverter to function on his ac 120v by improving the connection to the battery, but i do not know what the surge draw was yet

The surge inrush is 54.9 amps times 120vac is 6588 watts .    That is good after he got the battery connections tight and the room ac start and   run .     I  have to tighten my battery  terminal  all the time due to heat  expansion .  I check for loose connection when the temperature is more than 120 degree F  at the battery terminal under loaded  conditions .    

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thanks, I notice on some connections when charging, they either tend to loosen or they tend to stick as if welding together a tiny bit. perhaps it is the tightening down force i apply, or a galvanic type reaction between different metals... the LiFePO4 cells have welded on tapped aluminum terminals then i insert ss studs(set screws), nickel plated copper bus bars ,then a ss flat washer, the copper cable with tinned copper ring terminal ends from the Riden 6018 charger then a lock washer and finally the serrated flange nuts...i used that assembly on the last 32 cells ((280Ah EVE LF280K)) that I charged to top balance in sets of 4 paralleled together... (it tends to be more noticeable on the negative end while charging the bonding together - maybe just a coincidence🤔).

i did not want to scratch up the nickel plating on the copper bus bars....i think i create a bit of resistance with the ss flat washer and (will)may remove that in the final assembly....???

i kind of like the lock washer to hold things tight....i am not sure I like the Anderson style connectors as any type of long term connection ... and prefer the bolt-down method with set screws and a torque wrench....only thing i wonder is if some  type of electrical conductive paste would be useful to prevent corrosion for long term set up????

i do think an improper electrical connection may have been part of SuperRobkar's lack of success. I never heard the generator ever rev up long enough to actually output sufficient voltage in his video....so doubt that was a workable connection,,,, the battery connection on the other hand was likely the poor connection....

have a great day😎

thanks for all replies and guidance...

when I had a slightly loose connection in a 16 cell LiFePO4 build (2 years ago) it caused the cell to not charge correctly so proper torque down is essential. i need to check temperature of the connections some , i think that is a good idea !!!!

I'd remove the washer between the bus bar and ring terminal too.  Anything between the bar and ring terminal will increase the resistance simply by being there but also it probably isn't making full proper contact.  It's difficult to get enough force to flatten everything down tight against everything when you are limited by the amount of torque you can apply to the battery terminals.  Excessively rigid (wrong choice of metal or too thick) bus bars can cause grief too as the limited amount of force you have to play with when using threads means you don't get proper contact.  Lapping them and the surface of the terminal can help with this.

Posts are better in this respect in that you are crushing down on the terminal with a bolt rather than pulling on threads in the terminal.  If you want to see how well current is passing through them use a multimeter in DC volts mode measuring between the actual cell terminal and the copper wire in the cable, or the bus bar for cell to cell connections.  It'll be in the millivolts (or it'd darned well want to be!) so the meter will need a few decimal points or an actual mV mode.  Then draw high current from the battery and observe the drop on each cell's terminals.

... and as seems to be happening more and more, youtube threw this up in the suggested viewing list just now.  Yeah, yeah, Google doesn't track people at all 😉  https://www.youtube.com/watch?v=EjBqng70ORc

yes, this video gives all the wrong answers,,,,he is fun to watch but often gives bad information... i had already watched his video and had to comment against most of his testing and results....a very bad bunch of information...

I need to be able to control the PowerJack's on/off switch with an opto-isolator or something to protect the batteries from over discharge in a more fool-proof automated system

All Powerjack inverter  has a fool-proof auto shut off when battery voltage drop to 43 volts .    The battery ( low volt adjust )  is adjustable  on the front of inverter with a tiny screwdriver  to 43v to 49 v .     Somewhere  on this forum  someone say  opto-isolator  do not work  and not reliable .   

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the problem is with LiFePO4 cells sometimes >>>you have cells that are runners or losers depending on how you look at it. you do not want a cell to get below 2.5 volts as that can cause permanent damage and prematurely ruin that cell or drastically shorten its useful life span. i want he BMS which actively monitors each cells voltage to turn off the discharging just as it now turns off the charging....

there is no way PowerJack has any way to correctly monitor the individual cells, and if a problem develops due to incorrect connection or just a plain old bad cell, then i need to be able to cut off the discharging or turn the inverter off...automatically...

right now i watch them manually but not good for long term...

i will try adjusting the battery (low volt adjust) to see what that may do....thanks

need to control the discharging....which is due to the inverters....🤔🤔🤔🤔