Pure Sine Wave Inverter Power Board Post Sine Wave Amplifier Board

Thread Starter


Joined Sep 26, 2013
I have a "just out of warranty" 2000 watt gasoline inverter generator.
The Generator still works but the inverter is dead.
The price of a replacement "potted" inverter board is as much as a replacement generator.
My thoughts are in the direction of a Chinese Inverter Power Board.
There are many but the majority have the same - computer translated - description which my brain cannot digest.
It seems to suggest that these are "modified sine inverters" that must be modified to become pure sine inverters????
The following dialog is very very common.......................


Product Name: Modified sine wave inverter change pure sine wave stage plate
This product is a Modified Wave Inverter to Sine Wave Inverter. It can change the 3000W modified wave inverter to a pure sine wave inverter.
Input voltage: DC380V.
Input voltage: AC16V.
Output voltage: AC220V.
Output frequency: 50 / 60HZ (adjustable)
Output waveform: pure sine wave.
PCB Specifications: 200X85X50MM.
3000W power tube use: 8x 47N60 or 8x 40N60


First remove the modified wave inverter rear stage power tube, then check how many transformer there are, and confirmation if the transformer secondary circuit is connected in parallel or in series. After confirming all of the above, then add the transformer parameters. If the modified wave transformer secondary is parallel, add 16 turns in the secondary of each transformer, if the modified wave transformer secondary is in series, adds 8 turns in each transformer secondary. Then add a small voltage parameter to one of the transformer's empty feet in the modified wave transformer. This small voltage parameter uses a single 0.6 copper wire and wraps around the transformer for 5 turns. This small voltage is connected to the AC16V position. (Note: Do not open the magnetic ring when the transformer is adding parameters) After the transformer parameters are added, be sure to change the high-voltage capacitor of the modified wave inverter back to 220UF/450V. Power test high voltage capacitor (positive / negative) voltage is DC380V, after the test voltage is normal, use the connection line to provide the sine wave rear stage board, after the output voltage of the rear stage board: AC220V/50HZ, output waveform: pure sine wave.

Package included:

1 x 3000W finished board with radiator bangood inverter.jpg
Can any one put this into meaningful words please.
Also none of these will be an easy neat physical fit inside the generator AND as a 2000W and 3000W unit costs almost the same, would it be better to use the higher powered unit?

Many thanks



Joined Sep 17, 2013
So far as I can make out from that Chinglish spec, the unit seems to be an add-on for a modified-sine-wave inverter; not something to replace your dead inverter?


Joined Sep 6, 2014
I think, that the idea of the unit is to remove original output stage from the modified wave inverter and install this unit instead. Input is 380vdc. The control board of similar units makes "pure" sine wave output. Output voltage of the generator should be about 380vdc.

The unit requires 16 vac for the control section, which should be made from the generator output voltage.

Thread Starter


Joined Sep 26, 2013
As I understand the alternator puts out around 440 volts 3 phase AC
This goes through a 6 diode rectifier creating 380 volts DC
The 380 volts DC is fed into the inverter along with 16ac (to power the inverter)
The inverter then produces 220 volts AC

My understanding from the poor English is this device, as it comes, produces a modified sine out put but can be tweaked modified to produce a pure sine output.


Joined Sep 6, 2014
My english is actually finglish, but I interpret the information so, that the device makes pure sine output. Of course, could be wrong but here is my reasoning:
-pure sine wave on the device title
-Features: This product is a Modified Wave Inverter to Sine Wave Inverter. It can change the 3000W modified wave inverter to a pure sine wave inverter.
-Output waveform: pure sine wave.
-Instructions: First remove the modified wave inverter rear stage power tube -> I read this so, that remove the output (mosfet) stage of the existing modified wave inverter

Images are informative too and there is EG8010, Single Phase Sinusoid Inverter ASIC on the control part. From EG8010 datasheet, EG8010 is a digital pure sine wave inverter ASIC (Application Specific Integrated Circuit). The big "inductor looking component" fitted with cable ties looks to be an inductor of output LC filter and the two red/brown caps beside it could be capacitors of output LC filter.

You should measure the AC and DC voltage level of the generator. 440 VAC rectified is nominally about 440 V x 1.35 = 594 V but the circuit in the generator might be different from typical industrial three-phase 6-pulse rectifier.

Thread Starter


Joined Sep 26, 2013
Nothing wrong with Finglish .... If I am guessing correctly Finlandish-English
HUT is my Valhalla
The generator voltage was from specs ....not measured