my home made inverter circuit

[Nickk2057]

anyways.... i will be getting some high amp transistors soon... just hope they arrive soon... i am running out here

[c4757p]

Are you breaking them by making mistakes, or does this circuit eat them when it's operating "properly"?

[Nickk2057]

oh it operates correctly... just with the load it goes out... maybe i should put them in line to make it go higher in power to the transformer.. and also a more heavy guage wires to help it

[c4757p]

You can safely parallel them, though if they have a large gate capacitance you may find that the oscillator has to be redesigned a bit to be able to drive all those gates.

What I'm concerned about is that if that transformer isn't "perfect", you could be getting some nasty high voltage spikes that are blowing up your transistors. If you have access to the parts, try adding something like this. (If that resistor gets hot - not warm, hot, then you have a problem that a little snubber isn't going to solve. And don't touch it to find out, at least while the circuit is running.) It will eat some of those spikes. The parts are important, though - the resistor can't be too low in power rating, the capacitor has to be able to handle a good bit of voltage, and the diode must be a fast rectifier (no 1N400x or anything).

Edit: Er, yeah, I'm aware that the center tap goes to +12, not ground...

[Nickk2057]

its really not the high voltage spikes that was killing them... it was the load itself... meaning i was trying it out on a bench grinder to see if it will start up and blew it out... lucky i had a resistor between the arduino and the gates of the mosfets

[c4757p]

its really not the high voltage spikes that was killing them... it was the load itself... meaning i was trying it out on a bench grinder

Are you breaking them by making mistakes

Yeah, I'm pretty sure sticking a bench grinder on a homemade inverter made with a couple FETs and a backwards mains transformer counts as a mistake... 

[c4757p]

lucky i had a resistor between the arduino and the gates of the mosfets

This may be part of the problem. The resistor will limit the rise time of the gate, and the poor little FET burns a ton of heat in the stage between fully off and fully on. Try putting capacitors (preferably the biggest ceramic or film capacitors you have) in parallel with the resistors, so that the resistor "disappears" while the voltage is transitioning.

[Nickk2057]

well the thing is that i don't want to blow my arduino out... and i am using 680Ohm 1/2W resistors too

[Nickk2057]

and also i know that each of the PWMs on the arduino is only about 50ma each... and also here is the programming i got too and also added two more poles on there to use two more mosfets..

int pin1 =  7;
int pin2 =  8;
int pin3 =  9;
int pin4 =  10;

void setup()   {               
  pinMode(pin1, OUTPUT);     
  pinMode(pin2, OUTPUT);
  pinMode(pin3, OUTPUT);
  pinMode(pin4, OUTPUT);
}

void loop()                     
{
  digitalWrite(pin1, HIGH);   
  digitalWrite(pin2, LOW); 
  digitalWrite(pin3, HIGH); 
  digitalWrite(pin4, LOW); 
  delay(7);   
  digitalWrite(pin1, LOW);   
  digitalWrite(pin2, HIGH); 
  digitalWrite(pin3, LOW); 
  digitalWrite(pin4, HIGH); 
  delay(7);
}

[Nickk2057]

Plus there is a guy by the name of Kerry Wong that made this inverter as the same way i did..... and here is his site that made it too http://www.kerrywong.com/2010/03/12/a-power-inverter-with-arduino-pulse-source/

[Nickk2057]

i just hope it works out with that..... plus here is another one but with a modified signal too... but now my program has expired to use the oscilloscope on my input on my computer.... will update in a few....

void modifiedSineWave(float dutyCycle)
 {
  if (dutyCycle > 0.5) dutyCycle = 0.5;
  else if (dutyCycle < 0) dutyCycle = 0;
   
  cli();
  TCCR1B = _BV(WGM13) | _BV(CS11) | _BV(CS10) | _BV(ICNC1);
  //f0 = fclk / (2 * N * Top)
  long topv = (long) (F_CPU /(60.0 * 2.0 * 64.0));
  ICR1 = topv;
   
  OCR1A = (int) ((float) topv * dutyCycle);
  OCR1B = (int) ((float) topv * (1 - dutyCycle));
  DDRB |= _BV(PORTB1) | _BV(PORTB2);
  TCCR1A = _BV(COM1A1) | _BV(COM1B1);
  sei();   
 }
 
 int pin1 =  7;
int pin2 =  8;
int pin3 =  9;
int pin4 =  10;

void setup()   {               
  pinMode(pin1, OUTPUT);     
  pinMode(pin2, OUTPUT);
  pinMode(pin3, OUTPUT);
  pinMode(pin4, OUTPUT);
}

void loop()                     
{
  digitalWrite(pin1, HIGH);   
  digitalWrite(pin2, LOW); 
  digitalWrite(pin3, HIGH); 
  digitalWrite(pin4, LOW); 
  delay(;   
  digitalWrite(pin1, LOW);   
  digitalWrite(pin2, HIGH); 
  digitalWrite(pin3, LOW); 
  digitalWrite(pin4, HIGH); 
  delay(;
}

nd those icons of the sunglasses smilies is the 8 area in there.... Not an emotioncon

[c4757p]

Dear  ,
 How are you?
 This is Frank ,CEO from HTD Co.Ltd.

Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

[Nickk2057]

thats EXACTLY what i was about to say...


Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

[Nickk2057]

and on a forum too...

Well if he ran up to people in the middle of the street shouting that he supplies PCBs for Lenovo he'd probably get himself pepper-sprayed by someone who thought he broke out of the loony bin 

exactly... i think we should tell Dave this... if he is around that is since he is always so busy with shit


Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

[c4757p]

i think we should tell Dave this...

You mean the spamming? "Report to moderator". Already done.

[Nickk2057]

i think we should tell Dave this...

You mean the spamming? "Report to moderator". Already done.

cheater 

[c4757p]

cheater 

I fucking hate forum spammers. I pounce on that link when I see them. Stupid fuckers.

[Nickk2057]

if i was you i would go over there and spam them back XD... THAT will get there attention   

[Nickk2057]

well.... i think i will order the FET's today... i hope lol

[Nickk2057]

well.. i will be ordering the MOSFETS soon... tho i have to wait till i get paid first... lol... but will get some soon

[c4757p]

Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

I did... 

Anyway, just thought I'd mention - I came very close to using something like this circuit as an unregulated, high power step down converter. Speed it up to 30 kHz, slap on a couple snubbers in case I suck at winding transformers, custom wound transformer (two center-tapped windings, 2 x 2 mH and 2 x 125 µH, on a toroid), full wave rectified by an MBR2045CT dual Schottky that I salvaged from a power supply gives 30VDC -> 6-8VDC at 5A. Works fine, but I think I'm going to skip it and do a regulated one instead...

[andrealmer]

can someone helP me build a 15kilowatt inverter   

[Nickk2057]

can someone helP me build a 15kilowatt inverter   

 depends on what it is... does it have to be a square wave or a sine wave type?

and what circuit you looking for?


 and be sure to have alot of transistors handy and alot of other stuff too... or else you will have alot of  crap there

[Nickk2057]

Moderator: If you see a post that you think should be removed, use the Report to Moderator button at the lower right of the post.

I did... 

Anyway, just thought I'd mention - I came very close to using something like this circuit as an unregulated, high power step down converter. Speed it up to 30 kHz, slap on a couple snubbers in case I suck at winding transformers, custom wound transformer (two center-tapped windings, 2 x 2 mH and 2 x 125 µH, on a toroid), full wave rectified by an MBR2045CT dual Schottky that I salvaged from a power supply gives 30VDC -> 6-8VDC at 5A. Works fine, but I think I'm going to skip it and do a regulated one instead...

how so you mean as in to be regulated? 

[c4757p]

can someone helP me build a 15kilowatt inverter   

15kW?? No. No amount of tinkering will get you 15kW, though it might get you dead. It's going to take a ton of experience, knowledge, and probably dangerous failures before anyone has a successful 15kW inverter. Buy one.

how so you mean as in to be regulated? 

With a controller circuit to drive it so that it gives precisely a certain voltage output, instead of the voltage depending on the input voltage and load conditions. Currently I'm using my old standby MC34063 controller with an unnecessarily big output transistor (all I had   ).