Hi
I am trying to make a simulation of a self-driven H-bridge rectifier, as a replacement for a full-bridge diode rectifier (don't want any diodes in the rectifier because of high drop). I came across this rectifier circuit in some research papers, which uses two PMOS (M3,M4) and two NMOS (M1,M2), which are driven by the AC voltage input itself.
For a 100V sinusoidal input, I get just a 700mV DC output, corresponding to a ~225mV sinusoidal voltage across L2 (and 700mV sinusoidal across L3, so rectification is taking place just fine). However, my concern is the huge drop in the input voltage due to H-bridge rectifier. In absence of the rectifier circuit (the portion after 55pF cap), the voltage across L2 comes out to be 22V. Then surely there is some part of the rectifier circuit that is immensely loading the input circuit.
The load resistance is 10Meg so that shouldn't be a problem (same results for open circuit).
I need to make the circuit work for a 1V sine input, which won't be possible in this situation as the MOSFETs have a threshold voltage of ~0.7V, so they are never going to turn on.
If someone could help me with this issue it'd be great.


Green- voltage across L2; Blue- voltage across L3; Red- rectified voltage across C2

 

Look at where you put the P and N MOSFETs. Is that what you want? Maybe, just never seen it that way.
Please post a link to a research paper.

 

Look at where you put the P and N MOSFETs. Is that what you want? Maybe, just never seen it that way.
Please post a link to a research paper.

https://ieeexplore.ieee.org/abstract/document/9201538

 

I need to make the circuit work for a 1V sine input, which won't be possible in this situation as the MOSFETs have a threshold voltage of ~0.7V, so they are never going to turn on.

True.
To get it to work with such a low voltage you will need an addition circuit to drive the MOSFET Vgs to several volts to turn them on and off in the proper sequence.

 

https://ieeexplore.ieee.org/abstract/document/9201538

I see it. Thanks.

 

Is there no way to increase the output? Why is there so large of a drop

 

Please attach your schematic.
I think R5 is very wrong in value. Try 5 not 5k, or 0.5.

 

Is there no way to increase the output?

A step-up transformer to supply the necessary gate voltages might work?

 

That circuit will not work with a capacitive load, since it will discharge through the MOSFETs when the input voltage drops below the capacitor voltage.
You need a circuit the control the MOSFET Vgs so they go to zero when the input voltage drops below the capacitor voltage.

Below is an example of such a circuit:
But the input voltage still needs to be above the maximum Vgs(th) of the MOSFETs.

 

Is this circuit intended for an acul application?? Or is this just an intellectual exercise?? or maybe homework?
Given that the TS is listed as a student, I suspect either answer #2 or #3