[SOLVED] Pic 16f876a Pure Sinewave inverter

[jami007]

all your values are correct except b/a, it depends on MOSFET Rds and output current magnitude, approx. 1 - 2V max.

here are the comparable values

• V_OUT = 2.5V +/- max 1.5V (min 1V, max 4V, middle point 2.5V, sine wave)
• curr_h = 2.5V +/- max 1V (min 1.5V, max 3.5V, middle point 2.5V, sine wave)
• curr_l = 2.5 V +/- max 0.25V (middle point 2.5V, sine wave)
• volt = 4.45 - 4.82 Vdc
• Stdby = 0 - 5 Vdc

 

[daniello_85]

Hi jami007 & Californijoe, sorry:shock: i forgot to connect curr_h/l to MCU. My inverter start to run and it does work:grin:, but I had to put trimmer in "V_out" because the voltage in A-B is the 12Vac.

Now the value b/a is \approx 0.2V when the inverter is normal mode, but is 2.54V when my inverter is in stdby mode. One question, Is it necessary resistor 1k between b/a-GND?In my inverter is necessary. Thanks!

Regards:grin:

 

[daniello_85]

hello everybody!!

My inverter does work, my output voltage don't drop, it's correct. I had changed Vac_1 for Vac_2 and my inverter does work!!!!
My problem is the output voltage is 170Vac because Va-b is the 7.5V. It's very important the feedback!!!

yuhuuuuuuuuuuuuuuuuuuuuu!!!!
Thank you very much californiajoe & jami007!!
Best regards

 

[Californiajoe]

I am happy for you. Can you desribe more preciselly what did you do?

Regards

 

[jami007]

congratulations, atlast it works, so never forget to share your experience and results..........original credit goes to Taner who made it and share it....

*** Bless You

 

[daniello_85]

Thank you very much Californiajoe & jami007!

My problem was the output voltage drop 30V when i was connecting a load 50W, this problem happen because all feedback was trimmer. You tell me to proper work of inverter I must connect all feedback. Then I connected all my feedback, but the value of V_out was not correct. After I read the document on the operation of this inverter that i must tolerate the polarity of voltage, so as I changed "Vac_1" for "Vac_2". My inverter it does work!!!.

Note: When I connect V_out to MCU,output voltage don't drop 30V, but if i don't connect V_out to MCU, my output voltage drop 30V when i connected a load.

Now my problem is the output voltage is 178Vac (not 230V), but i was worried because my output voltage drop. Did you understand me?:wink::wink:

When I finish all my inverter, i will write a list of component because everybody can to do this inverter. Also I will comment all my experience.

Note: I must connect resistor 1K between b/a-GND

Best regards;-)

 

[daniello_85]

Hello everybody!!
I want to say that my problem is the output voltage are 178Vac (not 230V). I used software: sine_pwm_voltage-regulator_without_a-b_voltage_check, my output voltage are 230V!!!!:grin:

Californiajoe, you tell me in other post:
"One more thing: I just noticed that pin 2 of 16f876a had to high voltage on it (over 4V) and there was no PWM and A/B signals from MCU. After connection of the resistor ( 1k ) from pin 2 and GND inverter started to run."

Is extremely necessary to connect resistor 1k between pin 2 MCU to GND?
Best regards!:wink:

 

[Californiajoe]

I did it just for test. With correct feedback signals there should be less then 1 volt on pin 2.

Regards

 

[Californiajoe]

I think, it is already done what you are looking for. My advice is to read everything from the begining, could be helpful.

Regards

 

[vminga]

Hello to all
Please help me, I think my PIC is broken at the pin 5 (V_BAT)(I put directly 12V wrong in it).
Now voltage for this pin is 0.4V.
Can I re-program (change the analog input) for this project?
I' m beginner in c program

Best regard

 

[babalola]

Hi,
You can try your luck, but i'am afraid the chip may be gone for good

Regards

 

[jami007]

hey guys after successfull completion of our project, now i'm thinking about converting square wave inverter into sine wave inverter, whats your plan?

 

[Californiajoe]

Can you explain more precissely, what you plan to do?

Regards

 

[jami007]

there are two options

1- convert square wave into sinewave with 100% efficency
2- generation of sine wave output using microcontroller with exsisting/little modification in circuit

 

[Californiajoe]

Well in case of option 2, I would join to experiment. Can you please describe both of options preciselly?

Regards

 

[jami007]

I'm starting research, the best one is the option 2, so in this I'll try to use basic principle from taner's project, fast and controlled switching of MOSFETs/IGBTs, i'm beginer in pic coding so I need your help for editing taner's code into simple pwm generator/controller with out any feedback

---------- Post added at 16:48 ---------- Previous post was at 16:47 ----------

i.e we use basic switching principle of inverters

 

[Californiajoe]

I am also beginer in PIC C compiler, I usualy programm in mikroBasic, but we are learning all our life.
What would you keep in Taner's code or what would you change in his code?

Regards

 

[babalola]

HI ALL,
I will suggest you generate just two spwm from the PIC ---CCPR1 &CCPR2 directly into the driver to the MOSFETS without the steering
logics in tanners work. i hope this will simplify the schematics but with little additional software overhead.

regards,

 

[dgrude]

Re: pwm inverter circuit

hi EVERYONE especially taner!!
could you please post me a PCB design of your inverter, because I try to draw it but I failed. I have to do it for my final PRODUCT in my high school!

Thank you very much!

 

[jami007]

dgrude, Californiajoe already uploaded the raw files for pcb (in Protel) download them and enjoy

---------- Post added at 11:46 ---------- Previous post was at 11:44 ----------

Californiajoe

we will start with the basic switching principles of inverter, i.e using pwm, without any feedback from the output