# LTspice AC/DC converter with DC/DC boost converter

So this is my first time using LTspice and I need to convert my (AC) Vin 11.5V to DC and then boost DC voltage to Vout 22.5V. I have a few givens and some I needed to calculate. I am struggling to find Ripple Voltage and Ripple Current. I also dont know what values to allocate to my capacitor or inductor. (Continuous Conduction Mode)

Duty cycle is 0.5 I have a switching frequency of 270kHz, AC frequency is 50Hz average current load is 2.2A

Any notes or ideas would be amazing.

• I'm rather weirded out by the direct application of a switch to L1 against a backdrop of a 50 Hz bridge rectifier without any attempt to develop a relatively stable DC source at the left end of L1. I've never seen it successfully attempted this way before and I'd love to see the analysis for it. (I would not love to do the analysis for it.) Would make for a very interesting white paper, I suspect. I guess this says I can't help with the question. :) Commented May 7 at 13:13
• How would you recommend i attempt to stabilise the DC source before it gets to the left side of L1? Commented May 7 at 13:21
• I feel you must understand why I wrote as I did to understand remediation I might suggest. The bridge rectifier subsystem on the left is a common starting point. The switcher subsystem on the right is a common topology, too. But there is usually something put in between them. Have you looked over any working schematics that include these two subsystems? If so, you should readily see what's missing (to my eye, anyway.) Think about what's going on with the bridge and what L1 "sees" looking in that direction. Can you put yourself into a position to see that side of things? Commented May 7 at 13:29
• I had a feeling that I would need another capacitor to smooth the ripples from the bridge but i was unsure, this that the avenue you might be hinting? Commented May 7 at 13:47
• Generally, yes. But you have an answer that addresses this more clearly. Commented May 7 at 13:54