This is a heavy duty design of a Pulse Width Modulator DC/AC inverter using the chip SG3524. I've been using it as a backup to power up all my house when outages occur since aprox.
6 years non stop. If you like the work and intend to build the circuit don't forget to click on the 'I made it' button so I know how many people benefit from the design, Thanks.
Notes: 1 The schematic circuit design is for a 250 watt output, while the pics are of my 1500 watts inverter that i built, to increase the power of the circuit you have to add more of the Q7 and Q8 transistors in parallel, each pair you add will increase your power by 250 watts, ex: to get 750 watts of power from the inverter you need to add in parallel 2 of Q7 and 2 of Q8 to the original design. Hi Nick, it's me again. I finally built my first inverter based on your schematic (the one with MOSFET) but I replaced the IRFP250 and use IRFZ44N instead. I also removed the feedback transformer and connect the bridge rectifier (I used KBP307, with 3 A ratings and 600V max. Voltage) directly from the main transformer.
EGS002 Sinusoid Inverter Driver Board User Manual 1. Description EGS002 is a driver board specific for single phase sinusoid inverter. It uses ASIC EG8010 as control chip and IR2110S as driver chip. The driver board integrates functions of voltage, current.
The problem now is the inverter didn't work. I measured the voltages across the MOSFET without the transformer connected to it.
The probes connected at the 'Drain' pin of the MOSFET and the others at the CT input of the transformer (or the Vcc which is 12 V in). The results are both of them had a different voltage, one MOSFET shows 10.1 V and the other one shows 5.78 V. When I connected the transfomer to the terminal block (which contains two MOSFETs and 12V Vcc) to the the transformer primary windings (12-0-12).
I measured the voltage drops at the main input terminal and it shows about 8V-to-11,1V while the battery is measured at 12,67 V. And also the MOSFETs seem only work alone (The ones getting very hot and sometimes the two getting hot together) these conditions can be swapped, I mean it can be the upper MOSFET connected to the pin-14 or the MOSFET at the pin-11 of the SG3524 that getting hot while the other stays cold. Here's my schematic diagram compared to yours. There is reason he is using feedback transformer. If you don't like the additional transformer, you can use separate power supply 12V. The ones you are using with (resistor 220K) giving you about only 3V output (simulated with everycircuit) just look at the output bridge, he is using 10uF that's why peak voltage dropped and down to 3V with 12V 30mW load.
That's why you never reach any point to turn this IC on. You can't 'hacking' circuit with only voltage divider resistor.
Try with author intention first design if it works, then you can try to build 'custom' as you like. Hi sir, i have a question regarding about the transformer, i want to rewind a transormer 12- 0- 12 to 230vac 5000 w or 10000watts, instead of rewinding 84 -0 -84 v to 230 vac 5000w to 10000w. My question is what is the difference between low voltage in the primary at higher wattage output? Is there any effect to my power output transistor? I decide to rewind a 12v in the primary section because if you rewind a higher voltage in the primary section, more batteries are needed and its expensive, please give me an idea. Thank you very much sir. Great to see a collaboration here literally developing a power inverter together.
Congratulations Nick for your simple design. I am also offering everyone a possible improvement regarding the paralleled output transistors. I recommend that each transistor have a series resistor say 100 ohms in series with the base connection. This is because each transistor junction conducts differently to another and one transistor will conduct more than the others, which will starve the others of current. This can cause unequal collector currents, resulting in more stress for one transistor over another, resulting in less longevity for that transistor. The series resistor will drop a certain voltage allowing the transistors to share better. Any engineers care to comment on the value of resistor I recommend?
Maybe 47ohms instead? Thanks and Regards. Edward Novotny.
After some research, I have found that it is better to put the low value resistor in series with the emitters rather than the base because importantly. It protects for thermal runaway at the same time as balancing the current in the output transistors. As the thermal runaway current goes up, due to constantly increasing transistor temperature, the resistors in the emitters will decrease the 0.6 volt junction drive voltage, which then decreases the collector- emitter current to safe levels. Resistors need only be 0.1 ohm, wire wound 5 Watt.