EEVblog® Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: merymery on March 22, 2021, 05:17:19 pm
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Hello, in the article below, a 30 MHz resonant SEPIC converter has been designed. For my homework, I am trying to make a circuit with 3.7 V input, 2.9 V output voltage and 1.5 A output current, operating at 10 MHz switching frequency. First I started with the rectifier design. The rectifier design is based on fr, Zr and k values. The k value starts with vo / vin and the fr value is scanned and the resonance frequency is selected when the input current and voltage are in the same phase. The Zr is then scanned until the output power is obtained. There is an ltspice file in the attachment. When trying to bring the current and voltage to the same phase, should I just change the fr or should I change the inductor and capacitor values as well?
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Are you asking someone to do your homework assignment for you? ::)
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Is this message understood from what I have written? I just wanted to ask if I should change only the frequency or the component values while bringing the current and voltage to the same phase? Because when I just changed the frequency, the current and voltage did not come to the same phase.
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When trying to bring the current and voltage to the same phase, should I just change the fr or should I change the inductor and capacitor values as well?
I have read this article a bit. It seems to me, the answer is here:
"The scaling factor k is selected first. The initial value of k is selected as k = Vo/VIN. Then fR is swept until vsin1 and isin1 are in phase. Once k and fR are decided, the duty ratio of the diode is determined" (III. PROPOSED DESIGN METHOD FOR RESONANT SEPIC CONVERTER, p.457).
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Hi,
in the LTspice model rec.asc, you have defined V2 as:
SINE(0 4.71 9M)
SPICE does not care about case
9M = 9m = 9 millihertz = 9E-3
If you want MHz
specify the source as:
SINE(0 4.71 9MEG)
9MEG = 9 MHz = 9E6 Hz
Your simulation will work at lot better. ;)
Jay_Diddy_B