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Guest Kasamiko

Another INVERTER we can talk about..

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Hi Sasi,

Nice compact circuit!

I’m not an expert but I believe the “dead time” here is very short and the only purpose is to prevent the output transistors from conducting simultaneous and explode! The modified sine wave inverters I have seen does not use the three level method described earlier but a multiple step ramp-up ramp-down output.

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How is this circuit for a modified sine wave

Yes, it is a square-wave with a single step in it. Some electronic equipment will work fine with it as their mains, and others won't.
Now all that is needed is a way to make it drive a push-pull pair of Mosfets that conduct through a center-tapped transformer. Don't forget that the peak voltage must be higher than if a square-wave is used.

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How about implementing Sasi's circuit with the osillator i posted above.

Your circuit and Sasi's circuit are completely different.
Sasi's circuit appears to be a square-wave inverter with a very small "dead-time". Your circuit needs a way to drive output Mosfets.

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Your circuit has a positive voltage shift and very high resistor values. Mosfets need their inputs to be zero volts when off and low resistance values to switch quickly.
Use a counter with gates instead of resistors to make the signals that feed the Mosfets.

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I have found a way , why not use a Class D amplifier after generating a modified sine wave or a linear sine wave . We can use LM4652 and LM4651 to make a Class D amplifier. Here is a schematic for it . IF it has 125W efficiency 86% , it can be used for sine wave generation also .

post-15126-14279143012758_thumb.png

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I don't think the LM4651 is still being made. The National site says, "Lifetime Buy" instead of "Full Production".
A couple years ago I was going to design a pure sine-wave inverter using it when I found out it was being cancelled.

Texas Instruments and other semiconductor manufacturers make power class-D amplifiers that can be used to make a pure sine-wave inverter, not just a simple modified sine-wave one. The high efficiency is due to the PWM used to make it class-D so a pure sine-wave output also has high efficiency.

The class-D amplifiers operate on a supply voltage much higher than a car battery, and a big output stepup transformer needs to be used to make an inverter.

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Who says it is out of production . IT is in full production , look at the picture attached . ANd farnell also has it . But the problem is that the PWM IC LM4651 is out of production , can you tell me about the IC number of the Texas Instruments CLass D Amplifier IC. thnx

post-15126-14279143013135_thumb.jpg

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Here are the schematics any ideas about where is the input and ouput , because first i want to try out the 125W audio amplifier and see if it works. THe problem is that the TAS5152 side is easy to tackle and understand but i donot understand the PWM Section of where is the Input signal and how to implement it ... ??

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post-15126-14279143017302_thumb.jpg

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i think a evaluation board is neccesary to implement this . but the problem is that i cannot buy the evaluation board in my country , one of my relatives live there in toronto but i bet they don't know the location , audioguru you also live in canada , can you check out the Texas instruments distributer in toronto and look if they have an evaluation board for the TS5152 - 5508 , because iin the texas instruments site , it only says status : PREVIEW for it . but you can buy it from the distubuter , better go check it out... thnx

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Texas Instruments don't make an evaluation board with the TAS5152 IC.
They make one with the 40W IC that is available from TI but not from Digikey.ca, and with the 100W IC that is on back order from TI selling for $499.00US but not from Digikey.ca. 

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If only Texas Instruments would have an ACTIVE status on the TAS5152 Evaluation board , it would have beeen possible for us to actually get the USer guide at least , where all the PCB Layout and gerber files are given .

can i use SG3525 PWM Controller IC With this , it is also a PWM Controller

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