# Questions tagged [resonant-converter]

Questions about resonant DC/DC converters as well as resonant DC/AC inverters used in power electronics.

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### How does this high voltage device work? [closed]

In Ali express, I found the following high voltage small generator for fun. One transistor, one single coil, 2 caps and 2 resistors (not sure if the leds are an essential part of the circuit). The ...
• 1,712
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### Why does my resonant converter add more losses?

I am currently designing a DC/DC converter transmitting energy from a solar panel to a load, using a transformer. The model of my circuit can be found on this figure: To migitate the losses, I have ...
263 views

### How to reduce NPN reverse base current on this interesting "Super Efficient Joule Thief"?

Note: The question part is the fixing of the negative current at the transistor base. It looks like there's a problem with negative current at the LED(s) -- this is not expected to be answered in this ...
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1 vote
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### LLC resonant capacitor RMS voltage and output capacitor ESR calculation [closed]

I have a question about the TI LLC document. On page 25, Select the Resonant Capacitor, I don't understand why it can use this formula to calculate the RMS value. Could someone tell me how to get this ...
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286 views

### ZVS driver drawing too much current

Lately, I've been trying to build a ZVS circuit that follows the schematic shown below However, when I actually attach a DC power supply (eTM-305A) that can supply up to 5A @ 30VDC, and crank is past ...
47 views

### Terminal AC voltage of the resonant inductor in LLC resonant converter

For this LLC resonant converter circuit, the switching frequency is calculated between 80 to 127 kHz. To select the terminal AC voltage of resonant inductor(Lr), the formula is used as below in TI, ...
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129 views

### Convert DC frequency (square wave) to AC

I have a DC frequency generated as a square wave from a 555 at 14 kHz (actually will be using a variety of frequencies but 14 kHz is one as example) with a voltage of 4.0 V. I want to convert this to ...
1 vote
64 views

### Why does input DC supply gets short circuited when operational amplifier is connected at the output of LLC resonant converter?

Following is the block diagram of LLC resonant converter, more clear circuit can be found here. This is an LLC resonant converter which produces 250V across RL with 50V at input without any issue. ...
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### Limit of resonant converters

I am currently trying to design a converter with GaN technology. The converter needs to regulate a wide range of current and consequently the power goes from ~1kW to ~10kW. I took a look on Texas ...
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### Resonant converter - negative voltage on resonant capacitor

I built/designed a one switch resonant converter with a simple integrative feedback control only. I found they after some (increased) loading the resonant capacitor becomes charged to negative voltage ...
42 views

### synchronous rectifier controller having high voltage drain-source sense pin

I am looking for an IC that is suitable for synchronous rectifier operation and having high drain voltage sense pin. Most of the ICs (NCP4306, IR1168, UCC24612) are having drain sense pin up to 200-...
50 views

### Trying to Dampen a Boosted LC Circuit

I am currently implementing the circuit shown below where the first stage is a boost converter and the second stage (output stage) is an LC circuit with a boost topology. The goal is to take a 24V DC ...
71 views

### Closed loop control ZVS buck converter

I have a buck converter of 400 V input, 200 V output, 300 kHz switching frequency, power output 100 W. I am trying to put it into closed loop voltage mode control. It is working DCM mode. Modelling ...
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69 views

### Pspice AC analysis

I want to get the open loop transfer function bode plot of the converter. Here is my circuit:- The pins of the CCM-DCM1 model are:- 1 - NMOS Drain 2 - NMOS Source 3 - Diode Cathode 4 - Diode Anode 5 -...
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### Pspice giving wrong results

I have a ZCS buck circuit which I simulated on PSIM first, and wanted to simulate it in Pspice now with the real components. However, I am getting wrong results in Pspice, and I can't figure out why. ...
• 151
137 views

### High frequency inverter using irf540n

I want to make a square wave inverter for DC resonant converter. I have constructed this full-wave bridge inverter which is to work at frequencies of 50kHz to 100Khz. The input is 37V DC. The gate ...
55 views

### Calculating output voltage of a boost converter circuit

This a problem with a circuit of an up-converter, consisting of a constant voltage supply (E), a switch (SW), a diode (D), a coil (L), a capacitor (C), and terminals as shown in the figure. i(0) = 0 ...
167 views

### Error in resonant converter simulation

I designed a closed loop resonant buck converter using voltage mode control and simulated on PSIM. Here is my circuit:- This gave correct results. Now I want to design an input filter so I simulated ...
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1k views

### How to correctly use the formula for calculating the air-gap in a pulse transformer?

To achieve a certain value of the magnetizing inductance (Lm), we can adjust the transformer air gap. Air gap calculation formula: There is no particular information on this, but I assumed that: <...
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1 vote
94 views

### How to correctly calculate Coss and Cstray capacitance in Full-Bridge LLC?

To select the correct value of the magnetizing inductance Lm, it is necessary to observe the equation: This allows the selected Lm to completely discharge Coss and other parasitic capacitances during ...
• 419
138 views

### What type of transformer is used in LLC converters? Is resonant or pulse the same thing?

Often in the description of LLC converters, I hear the mention of a resonant transformer. On Wiki, I found both resonant and pulse transformers. In the photos of the LLC converters - the transformer ...
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### Why does the LLC converter have an Lm inductor? How does it interact with the LC circuit?

Task: to understand why the LLC converter has Lm inductance and how it interacts with the LC circuit. What I learned: LLC converter circuit: The LLC converter is a DC to DC buck converter (...
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212 views

### Equation 20.16 Proof

In studying the Fundamentals of power electronics by Robert Erickson I do not understand how they arrived at the equations for current and voltage Link to Book, page 772 is where I am at https://...
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### Uneven current distribution in center-tap transformer secondary winding of LLC resonant converter at low load

I'm trying to design an 24V 50W LLC resonant converter with a resonance frequency of 250kHz. I've run into an issue with the center-tapped transformer that i can't quite find a reason for though. For ...
76 views

### Resonannt frequency of resonant current converter DC/AC

I have to work with this topology of resonant current converter, and I want to clarify some points: T1 is a transformer that I should specify to designer LT is a tuning inductance T2 is a ...
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### How to estimate NMOS Cds+Cdb capacitance from VDMOS Pspice/LTSpice model?

I'm designing a fly-back converter and in order to calculate the switching frequency I want to know a method or formula of how estimate the Cds+Cdb capacitance of NMOS switch using the Pspice ...
269 views

### High Voltage Planar Transformers

I am designing a high voltage DC/DC converter that is for an aerospace application and therefore I am focusing on reducing the size and weight, so switching at a high frequency possibly integrating ...
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### Difference series resonant and LLC DC/DC converter

What is the exact difference between a series LC resonant converter and an LLC converter. From a topological perspective, they seem to be exactly the same. I believe that for an LLC, also the ...
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### Series and Parallel RLC Circuit [closed]

I am trying to build a resonant circuit for data communication between coils. Which would be better, a series or a parallel resonant circuit? What is the difference between them and in which ...
315 views

### TL494 minimum operating voltage VCC

Has anyone operated TL494 on +5VDC practically as it works in simulation software ? minimum operating voltage indicated in datasheet is +7VDC . please confirm.
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319 views

### LLC resonant converter with air core

Is it possible to do an LLC resonant converter with an air core transformer (wireless power transfer)? I've read basics about it but I've all read that they use some type of ferrite cores. I think ...
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### Power Connectors for higher frequencies

I am currently involved in developing a resonant-converter for research purposes. One idea was to have two separate boards for each side of the involved transformer, while the heavy transformer could ...
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943 views

### How to dampen a royer oscillating power circuit [closed]

I have a great open-source board for induction heating here from Fluxeon which uses a Royer oscillator. It does a pretty good job and I already had it delivering power up to 1.5kW. However I continue ...
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1 vote
2k views

### Can I increase current using AC resonance?

In a resonance, specially if we resonant at the natural frequency, the generated waves' intensity will add up thus resulting in a wave of ever increasing intensity. This phenomena is responsible for ...
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176 views

### resonant frequency in a series resonant converter circuit

I am designing a series resonant converter and wanted to convert 700 VDC to 100 VDC by using galvanic isolation. The switching frequency should be about 300 kHz (the output load is R = 1$\Omega$). ...
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2k views

### Induction cooker - highly irregular power transfer curve

I’ve designed a Class D series resonant inverter, for use in an induction cooking application, which is displaying a strange behavior in its measured current vs frequency curve. The topology, ...
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1 vote
748 views

### Is it possible to convert a low frequency signal into a higher frequency signal?

I have a signal generator that has an adjustable frequency range that is below the required frequency that I need. Is it possible to input a signal from my generator into a passive series RLC filter ...
1 vote
243 views

### Tune L C resonant circuit with semiconductors

I have an air coupled transformer consisting of a primary L C resonant circuit fed with feedback transistors and a secondary L C circuit feeding a bridge recitfier to power a small circuit over an air ...
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6k views

### Coil design for induction cooking system

I am designing an induction heating circuit using a half bridge, series resonant circuit. Wildly simplified schematic follows (will use IGBTs instead of MOSFETs for the final design, but they were not ...
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586 views

### What does the line "edge resonance between an inductor and a capacitor" exactly mean?

I am working on a project on DC DC converters in which the concept of soft switching i.e, zero voltage switching (ZVS) and zero current switching (ZCS) are used. One method to attain this is using an ...
2k views

### Real power and power factor for resonant RLC parallel circuit [closed]

I have no problem finding parts a, b and c, however I don't know how to get part d. You don't have to solve it for me(although it'd be greatly appreciated), but please give me somewhat of a hint or a ...
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4k views

### Four transistor/full bridge version of the Royer oscillator

For some time now, I have been trying to figure out what (in theory) would be the most efficient way transfer power across a transformer. Applications include high voltage power supplies and induction ...
568 views

### Can a Cockcroft–Walton generator exhibit resonant rise?

I set up what I believe to be a working royer converter, however I did modify it to use a pair of op amps rather than transistors (see below.) Anyway, instead of hooking the secondary to an lc tank, ...
1 vote
778 views

### Is it possible to build a inverter that operates at a frequency set by an LC tank using ONLY that LC tank and transistors?

I was always dissatisfied with inverters because it seems like an LC tank and transistors would be all you need. However, after much time spent simulating and a few false positives experimenting, I am ...
9k views

### Electronic Drivers for Fluorescent Lamps: How is the DC-to-AC Conversion done?

Pretty much all (somewhat inaccurately named) electronic ballasts for fluorescent lamps run off a DC voltage and have to convert it into AC to operate the lamp. The DC supply can come from rectified ...
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### Setting correct operating frequency for LLC resonant SMPS

I need to figure out if an LLC half-bridge resonant SMPS is designed (more or less) correctly. I am not an SMPS designer, and neither is the manufacturer, so I'm just reading a bunch of app notes and ...
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