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I was inspired to design this circuit by thirteen, two thousand watt, industrial power inverter circuit boards; I bought for ten dollars. I took one circuit board apart to reverse engineer how it worked, and it did not have a signal generator. They are four-bank push pull mosfet driven inverters, beyond the difficulty of building a four bank sine wave driver I don’t think the circuit board can handle a sign wave driver, so I designed a modified sine wave signal generator. The Optocouplers used in the circuits are A3120 and five volts drive the signal in side of the optocouplers, this made logic circuit components ideal for a signal generator.
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Signing UpStep 1The Signal Circuit
Pure sine wave inverters are best, however they are expensive to buy or build. Modified sine wave inverters will power some equipment square wave inverters will not, and cost about the same as square wave inverters to build or buy.
555 timers generally need a 1kW and a 1MW resistor to achieve a 50% duty cycle and adjust the frequency with the capacitor. An adjustable capacitor, a precise capacitor, or capacitors in series and parallel, can enable you to get the right frequency. However any multivibrator set for a 50% duty cycle will do for the first signal, and since where I live, AC is 60 cycle, in my signal generator the multivibrator is set for 120 cycles. However where you live AC may be 40 or 50 cycles, you may need to set the multivibrator for 80 or 100 cycles respectively. Every thing after the transistors is a compressed version of the circuit board I built the signal generator for. The flip-flop should have a negative transition clock, this is so the And gates are not on when the flip-flop toggles. Optocouplers are used as IGBT/Mosfet gate drives, Industrial inverters, logic inputs, and microprocessor inputs just to name a few appellations. They protect one part of the circuit from the power in the rest of the circuit.
555 timers generally need a 1kW and a 1MW resistor to achieve a 50% duty cycle and adjust the frequency with the capacitor. An adjustable capacitor, a precise capacitor, or capacitors in series and parallel, can enable you to get the right frequency. However any multivibrator set for a 50% duty cycle will do for the first signal, and since where I live, AC is 60 cycle, in my signal generator the multivibrator is set for 120 cycles. However where you live AC may be 40 or 50 cycles, you may need to set the multivibrator for 80 or 100 cycles respectively. Every thing after the transistors is a compressed version of the circuit board I built the signal generator for. The flip-flop should have a negative transition clock, this is so the And gates are not on when the flip-flop toggles. Optocouplers are used as IGBT/Mosfet gate drives, Industrial inverters, logic inputs, and microprocessor inputs just to name a few appellations. They protect one part of the circuit from the power in the rest of the circuit.
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first off I want to say that I love your circuit. Was good to know that I could finally make AC without using a programmable chip.
It did take me a while to get the circuit to function correctly.
I do have a question for you though, what kind of MOSFETs did you use and what type filters did you use for the AC?
I just built the signal generator for 13 Inverter circuits I bought for $10.oo Canadian.
If you look at the pic the circuit is filtered by four CD295 200V 1800uf electrolytic caps and four M106102125-524 2u2 K250 WN Metallized Polypropylene Film Capacitors.
The mosfets are twelve three hundred watt IRFP260N making the Inverters peak usage 3600 watts.
I told him to double the frequency no matter the duty cycles and run it through the first JK Flip Flop. Use the Q out put for the clock on the second KJ Flip Flop and the And Gates.
For a 60 cycle modified sine wave make a 240 cycles multivibrator no mater the duty cycles, the first JK Flip Flop will convert it to 120 cycles 50% duty. The second JK Flip Flop will select the And Gate to be triggered with the signal from the first JK Flip Flop.