Im trying to use a couple OP Amp PWM generator ccts to manage the load power.
There's a small section labeled "Buck Boost Chooser" which turns on the MOSFET controlling the output to the corresponding PWM generator. When Feedback is below Reference I want to turn on the boost PWM output, and when Feedback is greater than the Reference, I want to switch the Buck PWM output on.
The "OP Amp power rail" is good and consistent, as well as the "Reference Voltage" though aside from that, I'm having difficulty even simulating. Maybe my computer is just slow?
I can use PWM Voltage sources but they aren't dynamic like I'm trying to make this simulate as. I'm sure there are other chips that can create PWM better (SG3525a ect), but I don't know if LTSpice can simulate them ect. I'd also just like to learn a little bit and wanted to see if I could make the OP Amp circuits viable.
I'm looking for advice on how to go about something like this given the attached schematic. It doesn't seem like the duty cycle is adjusting dynamically like I'm wanting. Without the "Buck/Boost Chooser," both PWM generator output operate simulataneously and the boost FET flows outrageous current. So I'm trying to make it an either-or type of situation rather than operating at the same time.
Also, the feedback V signal is not the same for each input of the PWM generator, I've added blocking diodes to stop the chatter but it seems that its still a bit different for each tie in.
Maybe my OPamp sensing signals need to be reversed, I've switched them back and forth several times but I'm sure I'm missing something. I'd just like to see a current through the load that isn't 3A+, I've been tweaking it for quite sometime trying to gain a conceptual understanding of "when I do this, that happens" but I can't seem to find consistency. I'm not sure if my understanding of the "Buck/Boost" principles are correct, ie like inductor placement and switch placement ect. If you see something glaring please let me know, or if you see an obvious fix tell me that too, thanks!
EDIT:
The end goal is to be able to adjust the POT to create greater or lesser Reference V which the PWM generators/Choosers manage the load based off of. I'd like to learn how to use smaller parts while achieving the same end result, I've been simulating 100mH coils to level current in capacitive dropper ccts, but I'd like to see how to create a steady current without using giant capacitors ect..