/diy/ - Do It Yourself

>>1278576
If you are still around I've gotten a lot of progress and wanted to run it by you.
I set R2 at 120 ohms, which puts the minimum power outup ( @ 0.25A from CT) at 7.5W.
I then found that when R2 is operating at 50W the current out of the CT is 0.65A.
I then Assume R6 at 100 times larger that R2, making it 12k, which makes R3 360k in order to produce a 2.5V drop across R6 that would satisfy Q2's threshold voltage.

I then assume the Rds value of Q2 is essentially so low it acts like a wire grounding the gate of Q1.
From what I've real, grounding the gate of a PMOS is what allows source to drain flow. Correct me if I;m wrong.
So R1 is just a pull up resistor. I should set that to 10k? That's what I've always used for pull up resistors.

I Then found a Mosfet with a -2 to -4 Vgs(th) value and a Rds(on) value of 0.117.
I then chose R5 to be 20 ohms, which when added to 0.117 ohms and then in parallel with R2 gives and equivalent resistance of 17 ohms, which gives ~7W with an T on 0.65, and 107W at our max current of 2.5A.

I have no idea what value to give R4. And when I try to actually model this on Pspice it doesn't want to run it.
check out?