Step 1: FOOD
Step 2: LIVING IN TOWN
Step 3: COALMAN GENERATOR
Step 4: FLASHLIGHTS
Step 5: 400 WATT INVERTER
Step 6: SOLAR CELLS
Step 7: THE THINGS I BUILD
Step 8: MY BIG HYDRO PROJECT
I was inspired to design this modified sine wave generator 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 know the optocouplers on the circuit board cannot handle a sign wave driver, so I designed a modified sine wave signal generator.
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.
This final circuit just needs a couple tweaks on the battery monitor and fan control circuits.
I should be able to build a 120 240 volt 22,000 watt power supply to power my home with circuits left over.
Step 9: CONECTORS
Step 10: THE SIGNAL CIRCUIT FOR EVERYONE
Unless you can acquire a custom made transformer your circuit design is ruled by the transformer available to you, if the primary winding is not center taped you are limited to an AB driver. The only transformer you can play with is a center tap primary, if the primary winding is center taped then you can use an A, B, C, and AB inverter driver and it can be supplied with 12 or 24 volts and 6 or 12 volts you can’t play with the watts.
If the primary winding is 1000 watts run max then your inverter is limited to 1000 watts run max and about 1500 watts startup surges.
The transistors and mosfets should be watts doubled, take an IRF640 it is 200 volts 16 amps and 136 watts. That is 200 volts at 0.68 amps to 8.5 volts at 16 amps not 200 volts at 16 amps. An IRF640 will get hot at 12 volts 11 amps constant running doubling the transistors and mosfets will keep them from overheating at full wattage use.
Optoisolators protect the signal circuit from feedback and power surges; they send the signal from the signal generator by light in one direction to the transistor bank.
These three 50 Hz inverter circuit designs are easy to build and the signal circuit is accurate to 1%.
This circuit can be broken down to seven components.
1. Power Supply
2. Voltage Regulator
4. Signal Converter
6. Inverter Transistor Bank
There can be more components when you add charging and low battery circuits.
These circuits are 24 volts center grounded and AB type inverter; 12 volts center taped primary winding B type inverter, and 12 volt AB type inverter.
Voltage regulator components
Use 1-24 k& for 60 CY or 1-30 k& for 50 CY or 1-39 k& for 40 CY
Any multivibrator with a 240 Hz output for 60 cycles, 200 Hz for 50 cycle, and 160 Hz for 40 cycles will due for the timer circuit. The duty cycle is not important as the first JK flip flop converts the signal to 50% duty cycle and ½ the hurts’.
Signal Converter Components
2 to 4-1.5 k&
From the And gate output resistors to the rest of the Inverter circuit the value of the active components depends on the power supply and the inverter transformer.
Step 11: THE INTERNAL SIGNALS
I hope this will help others build Inverters.