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PWM as a square wave signal to replace CD4047

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COS

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Keep in mind, I am just an electronics hobbyist here so...

I wired up the following scheme and I get my expected voltage out as you see it here...
https://www.eleccircuit.com/wp-cont...ave-inverter-by-cd4047-lm3582sc10612n3055.gif
EDIT: I actually used a 120VAC Transformer.

Now, I need to go higher in freq to the tune of 250Khz - 400Khz. The scheme above was designed to run at 60hz with a 50/60hz wire wound standard transformer. Theoretically I would like the PWM set for "High current demand".

What I want to use is this to replace the CD4047...
https://www.onsemi.com/pub_link/Collateral/SG3525A-D.PDF

The following is a post from this site that uses SG3525A...


Now, what I lack are the smarts to determine the values of the RC trimming to plug in a variable resistor that will allow me to vary the freq out for pins 11 and 14.

I verified the transistors can handle that switching freq but the op amps I will need to look for a faster switching model.

You're probably asking why do I need to go higher in freq?
I am going to replace the big bulky transformer for a high power smaller one with a Planar Transformer (https://www.coilcraft.com/b0853-a.cfm) with a lower voltage out for a DC to DC/AC converter, connected in reverse of course. Those just came in today.

If someone could modify the first scheme I linked to with the replacement of the CD4047 and give values for resistor/pot's and capacitors, I would appreciate it. Also, if you can include the formula you used to derrive the values that would be great. It's one thing to give me an answer, it's another (better) thing to show me how you got it.

If you see any flaws in my attempt please point them out and offer a solution.

Thanks
 

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