I need help with power supply calculations

Thread Starter

coinmaster

Joined Dec 24, 2015
502
I'm trying to built two power supplies, one +/- 100v bipolar supply and one 160v supply.
I will use my own post regulator, I just need to prefilter the transformer voltage.
The problem is I need each supply to idle at 2A. In spice the ripple current in the capacitors at that idle far exceeds what they can handle, I have to use like 20 1000uf capacitors to achieve what I need.
I tried using a LC filter and an RC filter but the DC levels off at the bottom peak of the rectified waveform instead of riding on the top with an RC filter and It levels off somewhere in the middle with an LC filter.


Is there a way I can not have to drop a crap ton of voltage and not have to spend $300 on capacitors?
 

Thread Starter

coinmaster

Joined Dec 24, 2015
502
The DC is still level shifted in the same spot, it doesn't help at all. They also don't sell them higher than that that can handle that much DC current.
 

AlbertHall

Joined Jun 4, 2014
10,915
You could use a transformer with a higher secondary voltage.
You could improve the dropout voltage of the regulators. Show a schematic of the regulators.
 

Thread Starter

coinmaster

Joined Dec 24, 2015
502
There is no GND connection to the bottom side of the bridge.
There is, it's just hidden under text.
What is the p-p ripple voltage you must achieve?
A volt or two would be fine as long as the bottom of the ripple peak is above the regulator input. I need about 5 volts headroom for the regulator.
Ultimately I want the output of the regulators to be +/-100 to +/-105 and +150-+155 so I guess the 100v supply should be about 110-105v before the regulator and the 160v supply should be between 160v-155v before the regulator.
I'm looking at these transformers https://www.mouser.com/ProductDetail/553-VPT230-4350 so far for both supplies because it is the closest ratio for both that I could find.
As far as I know the rectified voltage should be AC x 1.141 but I'm not sure how to account for other losses.
 

Thread Starter

coinmaster

Joined Dec 24, 2015
502
What if I used a mains switcher to filter? Normally I stay away from such a thing because they require lots of evil math but it shouldn't be too hard to make a 1:1 and 1:2 CT switcher that only smooths not regulates right?
 
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