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34 Threads found on edaboard.com: Zero Voltage Converter
Transformers like that fail if they overheat and the insulation between turns of wire breaks down. When they do that the result is (hopefully) a blown fuse but the chances of one producing too much voltage is almost zero. The voltage it produces SHOULD be higher than battery voltage to enable it to 'push' power into the (...)
Hi, I am trying to implement zero voltage switching in a boost converter but I'm not quite sure how to especially in spice. I think I get the concept about it creating a resonant voltage oscillation and switching at the zero crossing but I'm not sure how to actually implement it. Any help would be appreciated.
It's not just wire inductance, there's also that the whole loop is probably "wound up" with I*R offset and when I goes to zero the converter is still pumping at a high duty cycle, which takes time to bleed off. More shunt C will soak that up, faster control loop, an overvoltage clamp external to the converter loop are all (...)
Hi, I was wondering whether switches in an inverter get rid of ringing completely by utilizing soft switching techniques. For instance suppose I have a full-bridge series-loaded resonant converter using Mosfet switches . Is it possible to eliminate ringing at the turn on and turn off instant by using zero voltage switching (ZVS) ? Does (...)
Hi, I was wondering whether switches in an inverter get rid of ringing completely by utilizing soft switching techniques. For instance suppose I have a full-bridge series-loaded resonant converter using Mosfet switches . Is it possible to eliminate ringing at the turn on and turn off instant by using zero voltage switching (ZVS) ? Does (...)
hi, How zero-voltage and zero-current switching are achieved in resonant converters? what is the working principal?
The circuit can only start if the output voltage is initially zero and will fail with light load. A possible solution is to replace D1 with a low-side transistor, implementing a synchronous buck converter.
A PFC input stage requires to draw a sine current waveform from mains input, down to ideally zero voltage. That's only possible with a boost converter and a DC bus voltage above peak value of input.
i used the attached circuit with atmega 8 to drive dc buck converter and it was working very well , then i increased the input voltage on the drain to 20v and the input current was 4 A (from a power supply ) suddenly the output on Ho of IR2112 was zero when i removed the converter the output on Ho was 7.6 v dc constant when (...)
I've been studying VHF DC-DC converters to see how to make the most efficient and smallest size of an envelop tracking power supply for an RF transmitter power amplifer. It needs to be a capacitively coupled (or transformer coupled) boost converter so the output voltage can go down to near zero volts. I'm thinking of (...)
Can anyone tell how the average flow in each cell of mmc is zero to maintain the DC link capacitor voltage constant?
Variable output down to zero can be usually achieved with standard regulators (linear or switched mode) by superimpozing a control voltage to the feedback network.
Hello, I am hoping that somebody can help me out. I am trying to simulate a power supply in Ltspice and I am having a problem This power supply is a zero voltage switching isolated full bridge converter. It take 18-30Vdc in and outputs 165V at 120W (0.7A) The problem that I am having is that the regulation poor. Also when the (...)
The "reflected voltage" concept only works for ideal flyback transformers (zero leakage inductance). For these, multiple output voltages are always tracking according to the windings ratio, independent of load currents. Thus there's no difference to the single secondary case.
There's no principle limitation to operate a buck converter with a duty cycle slightly abobe zero. In so far, I don't understand the meaning of the diagram. There's also no limitation for the switch transistor, except for achieving reasonable efficiency. voltage feedback is presumed, however. Duty cycles near zero will (...)
You can use a DC-DC boost converter (1-transistor boost converter). You can also use a push-pull converter. I recommend using the push-pull converter, as, when the switches are off, output is zero, whereas in the boost converter when the switch is off, VOUT = VIN. And the output is (...)
The circuit looks correct. The 390 Ohm resistor is a good idea - it's to help with zero crossing. R4 is not needed - it won't make any difference if you take it out.
Putting a voltage directly across an inductor will make the current rise at a rate of dI/dt = V/L. The resistance will limit the current and add some voltage drop. Normally you would try to minimise its effect if possible. zero resistance doesn't actually cause a problem. I cannot see a zener so cannot comment. Maybe if you post your (...)
i am doing a project of boost converter using zero voltage switching (ZVS), the overall schematic shown in figure below. am using timer 555 to generate PWM to trigger the mosfet, the frequency about 600hz, Vin = 12v, Vo=47.5v, duty cycle = 58%, so my problem is how to calculate the resonant components (L2,C5) to achieve the soft switching. (...)
I'm working on sensing the mains input for a power factor-corrected boost converter so I can detect the zero-crossings and also detect the peak voltage. I have placed a voltage divider circuit before the voltage bridge so that the voltage can be stepped down to a range that falls within my (...)
The zero crossings of the voltage waveform has to be taken as zero crossing ref...The current waveform square wave zero crossing needs to be compared against and a pulse developed to switch ON and OFF ..Width of this pulse is proportional to the powerfactor ....A Volt to Freq converter gives a readout
Sounds like an every days simulation problem. Possibly the converter simulation don't like zero input voltage. Try with suitable .IC settings. Also the isolation should be bypassed by a mnimal conductance (Mohm resistor).
Can you post a sketch of the gate drive waveform? Also you need to automatically vary the duty cycle down to near zero if the load is removed, and to allow for your varying input voltage. Regards, Orson Cart.
I am working on boost converter with PWM generator block in as VerilogA. When switch2 and switch3 are close and other switch remain open(off) than there is still some current remain in the Inductor. Also the difference voltage through Inductor is not zero at this Instant. I am hereby attaching the circuit .. Can anyone please give (...)
I am working on boost converter with PWM generator as VerilogA. When switch2 and switch3 are close and other switch remain open(off) than there is still some current remain in the Inductor. I was wondering that if both switch2 and switch3 when close than Inductor current must be zero and difference voltage in Inductor is (...)
how to include Rl in my derivation? Everything is correct. If A2 is an (ideal) opamp with (nearly) zero output impedance, RL has no influence on the output voltage.
I m looking for an op-amp based DC voltage converter: Input: -1Volts to +1volts. Output: 0volts to 2volts When Input=0volt, Output=1volt. Basically I need it for designing a center-zero LM3915 based level meter. Thanks.
The power MOSFET gate charge is shuttled once a cycle, ditto the loss-slug as the FET transitions through the dissipative region (zero voltage, zero current schemes are for this). More cycles per second, more joules per second (i.e. loss watts).
1. FISHER, NGO and KUO; ?A 500 KHz, 250 W DC-DC converter with Multiple Outputs Controlled by Phase SHifted PWM and Magnetic Amplifiers ? HFPC 1988 2. ANDREYCAK, W. ?Controlling zero voltage Switched Power Supplies?; HFPC Proceedings, 1990 and any papers related to design of phase shifted zvs full-bridge dc-dc converter
You don't need any current probe if you know how scope works, it seems you don't. On Y you need the measuring voltage. On X you need a ramp voltage. Every other signal than voltage must be converted to voltage (ie using a simple zero drop current to voltage converter (...)
If it is voltage mode, you can only do one thing: increase the low frequency gain of the error amp, that is, use a zero in the design of the opamp (actually two zeros).
It is too much question to answer and need too time to answer it,but I try: 1. DCM and CCM will effect effieciency,EMI,LOOP control,but it not simple difference. 2. soft-switch mostly is mean ZVS(zero voltage switching) and ZCS (zero current switching) 3. use resonant tech to realize zvs or zcs 4. linear -switching is simple,Pls r
I can see two possible reasons for not having 0V at the outputs: - zero-scale error --> ( fig.18 in the data sheet ) gives you the output voltage error of ≥0.5mV, depending on temperature .. - "Ground Reference Point for All Circuitry on the Part", which is pin labelled GND; this pin has to be used as 0V reference for all outputs, and
Did anyone know why the buck dc converter has a left-hand zero but the boost has a right-hand zero?Can supply some material about this topic? Thank you!