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Thanks for the link. The scopes that have integrated isolation have very low capture memory.
So i try to adapt the isolation to a 14Mpt memory.
My application is an LLC converter. (@400kHZ-1000kHZ).
1612004642
Thanks for the useful info. I already have a 1:100 HV probe. But as you said I...
I need to make a differential high voltage measurement for a power inverter. ( up to 4 channels)
The classic way is to use a high voltage active differential probe capable of measureing +-1000V cat3
But they are very pricey. Each one cost more than the osci and 4 of them is a huge investment...
I got it, But what happens when the reverse recovery is not fast?
Because as I understand it is important that the diode kicks in if the volatge rises above a threshold.
But why is it critical that the diode shuts down fast?
My uncertain answer: If diodes shut down slowly , there may be a...
I send the schematic. It was a rough estimation. The simulation result is Vcap=287Vpeak over 38nF capacitor @100khz @I=5A. (0.28A per 2.2nF)
1A estimation was a rough exaggeration to calculate power dissipation of the cap with a very large safety margin.
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I think the...
The topology is the capacitor-clamped half bridge LLC. Each cap is paralel connected with fast diodes.
These diodes act as voltage limiter (the diodes clamps the maximum cap. voltage to the bus voltage, any voltage voltage bigger than the bus voltage will be cut and crippled to the bus...
I am trying to estimate the ripple current of a capacitor bank of 8x MLCC cap 500V 2.2nF connected in paralel
Ctotal = 17.6 nF Irms = 8A
The datasheet have only ESR value: 0.009 Ohm up to 1MHZ, butno data for ripple current
Resonant freq of circuit = 200khz
If I calculate the resistive...
I am sorry that I repeat the scheme. But this is because I did not fully understand it. When we look at the following sketch ,I see that there is current flowing through Point A to Point B. (magnitude: Ia-Ic) . This means the secondaries of converter1 and converter 2 short each other.
I know...
I agree, I see the drawbacks of the LLC, I just wanted to investigateand and I am unhappy that the LLC does not meet the needs of the paralelization especially for paralel connected unsynch. converters.
Until now the I was tending to insist on LLC but the following limitation that I could not...
Why I insist on LLC:
1- Severe osscilations on the seconadry rectifiers.(especially at light load). Need heavy snubbers to damp.
2- Need 100V Mosfet or diodes for 10V output and 150V-200V class Mosfet or Diodes for 15V output, which raises cost significantly.(especially for 2700A output), LLC...
I agree,but even if I have a master voltage feedback and local fast current loop on slaves, there is a physical problem because of the nature of the LLC output signal. Its shape is sinus. And with sync. rectification if a converter has different freq and phase reference to another converter, the...
The reason I try to get all the freq. synchronized is that I want to use variable freq LLC at the primary side and sync. rectification at the secondary side.
So phase shifting is not possible (each converter have different freq. to regulate their internal loops)
I also have a problem with the...
Can we say that the capacitor is a voltage source and shorting the output while the secondary winding and its inductor is acting as a current source . The inductor as a current source should have then a high impedance.
It should mean that when one converters sync. mosfet is on and the switched...
I sketched the following arrangment to show the modules.
Each Module is a PCB (18cmx20cm) .They are stacked on another. Each converter delivers 3.4V..6.8V @300A. The outputs of the converters are connected togethar to reach 9x300A=2700A. Each converter has a secondary synchr.rectifier with...
I thank all of you for the detailed information. I send a sketch showing my concern that secondary windings shorting between multiple converters working at different frequencies and phases.
According to the following sketch, I see that there is a huge current flow between Point A and Point B...
In deed, I added the option paraleling the secondary AC output to compare it to the sync.rectification.
In switched state we can model the mosfet as a very small resistor.
So if we have different random sources with different phase and freq. the paralel connection of these sources even with...
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