EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: xReM1x on July 14, 2015, 10:55:22 am
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hi, I'm using EEVBLOG tracking pre regulator design and it works great only when there is the tracking pre regulator, but in my work in progress psu it doesnt work! what the heck?
here is the output of the pre regulator, the pre regulator doesnt track. also there is oscilliation.
(http://i.gyazo.com/a498e9a1306827926b1f4ac2d0dd9050.png)
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Try adding some resistors around Q3 like I did for Q1 below. That worked for me.
You can also safely leave out C6 & C9 (in parallel with V1) as V1 modeled as an ideal voltage source.
(https://www.eevblog.com/forum/projects/bench-power-supply-design/?action=dlattach;attach=121894;image)
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Try adding some resistors around Q3 like I did for Q1 below. That worked for me.
You can also safely leave out C6 & C9 (in parallel with V1) as V1 modeled as an ideal voltage source.
(https://www.eevblog.com/forum/projects/bench-power-supply-design/?action=dlattach;attach=121894;image)
thanks, I think it works but the simulation takes alot of time... so I'm still not sure. (and it just happend that im going to use simple switcher also to pre regulate. I have 20 LM2576 that I got from ebay. :D)
also, is the schematic maybe for dc electronic load? just assuming because of the current sink and all the other things.
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also, is the schematic maybe for dc electronic load? just assuming because of the current sink and all the other things.
The current sink is not connected to the output, it is connected to the high-side current sense and since the high-side amplifier is powered from the output, it needs a constant current source to keep its voltage relatively constant regardless of what the output voltage is without overloading the LMV431.
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Try adding some resistors around Q3 like I did for Q1 below. That worked for me.
You can also safely leave out C6 & C9 (in parallel with V1) as V1 modeled as an ideal voltage source.
(https://www.eevblog.com/forum/projects/bench-power-supply-design/?action=dlattach;attach=121894;image)
well, i tried it and it works on constant voltage, when I'm entering constant current it doesnt drop the voltage.
I set the current to 0.1V = 0.1A and put 1R resistor, so the voltage at output of the post regulator is supposed to be 0.1V. but its not, the output is the same voltage as the pre regulator feedback.