Boost Converter

Thread Starter

archxth_13

Joined Nov 23, 2021
24
Hello everyone
I am currently in the process of designing a boost converter so that it can be used for active power factor correction.
The circuit schematic is as follows:
Open Loop Boost Converter.pngThe inductor is wound with a toroidal core and as it stands the system is able to operate under rated conditions without any circuit failure. I have now moved onto the sensory circuitry portion of my system. I am currently testing my system using a switching frequency of a 100kHz and a constant duty ratio of 30%. I am inputting an AC voltage of 180V by means of a single-phase variac. The current predicament that I am on is that my system seems to be picking up a ton of noise on the sensors itself.
Sensor output.jpgThe sensory topology I am using is a voltage divider (with a filter cap of 10uF connected on the low-side resistor), which will be inputted to a ACPL-7900 and then further amplified using a differential amplifier.
ACPL.jpg
The maximum sensed voltage is 350V. Thus the high-side is 1Mohms and the low side is 470ohms, the filter cap added was 10uF. For the differential amplifier portion of my system I set R1 and R2 to 180kohms and R3 and R4 to 330kohms. Does anyone perhaps know how I might be able to fix this?
 
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Thread Starter

archxth_13

Joined Nov 23, 2021
24
During the debugging process I increased the size of low-side voltage resistor to 10kohms, so that I could potentially narrow down the cause of this noise. What I had noticed was that the noise from my actual system is as follows:
VD output.jpg
Could someone please confirm whether or not its my actual system is causing the noise? Lastly with my physical PCB design, I did make an error in connecting up the traces.
Mistake.jpg
Could this wire be the cause of all my problems? The wire is joined far away from the voltage divider that I am testing but just so that I rule out any potential causes, could there be a chance that this wire could be injecting the noise into my system?
 
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