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PSU "Schematic" help me understand AC/DC Bridge Rectifiers, Proper Grounding, and Series AC Connections

MATTHEW_KING

New Member
Although my schematic is not standard
I'm trying to build a proper PSU for my Alactron 500 series rack since PSU's for this model are no longer being produced. I need help determining if my design is correct, especially regarding grounding and connections for AC/DC, bridge rectifiers, and DC-.

Color Codes:

Purple: AC Red: DC+ Black: DC- Green: Ground I'm unsure if the grounding is connected properly, and I'm also concerned about preventing ground loops. Additionally, I believe a capacitor might be needed at the DC- line, along with fuses and components to smooth out the currents, as this PSU will be used with audio equipment.

Although my schematic is not standard, it should be clear enough to understand. I'm seeking practical advice from anyone experienced in electronics. Thank you
 

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- list all currents
- Are you skilled in low-noise PSU's?
If not, then this is a shopping question.
 
- list all currents
- Are you skilled in low-noise PSU's?
If not, then this is a shopping question.
Never made a psu in my life but I chose a toroidal transformer to reduce emf, I will also filter the power before and after the buck converters with capacitors and LC filters.. I'm just using chat gpt to understand better. been studying for 40 hours only.. I'll build it myself for better or for worse and implement a slowblow fuse in the beginning of it and a quick blow in the end.. As of now I'm trying to wrap my head around how the bridge rectifier works, if i should split ac cable one and connect that to rectifier 1 ac in 1 and rectifier 2 ac in 1 and put my second 24v wire into rectifier two ac in 2 im wondering if that would create 67DC +/- out of rectifier 2.. this DC will be pulsating so i need to send it into capacitor to have a steady flow to reduce noise, and improve stability, capicitors are rated appropriately.. the 500 rack with everything will draw 5 amps max, the current diodes are rated for 5amps which is kinda tight but its to prevent backflow as im splitting the rectifiers one output from capacitor 1 into 2 buck converters.. Its just is my current understanding of getting higher dc by splitting a 24v cable in two to get 24v to two different places and also attatch 24v_2 into rectifier 2 to get 48v _> 67V DC correct if the transformer can handle the amp pull or is my basic understanding of electronics wrong. As stated I've only studied electronics for 2 days but I'm kinda crazy so perhaps I learn quicker than most or burn down the house, idk. Also heatsinks should be able to manage the overall 25 watts of heat generated from this circuit. Specifically the buck converters that convert electricity to heat to get a lower voltage output.. I think..

Thank you so much for responding, im greatful for any help I can get.
 
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I'd use a separate dual 15V (or15-0-15) transformer for the +/- 16V, and linear voltage regulators, for a low noise audio system.

A dual would 24V transformer (or 24-0-24) can then be used for the 24V and 48V outputs, again with linear regulators. Basically, that could be a "floating" +/- 24V, with the most negative 24V out as 0V.

Do you have the current requirements for each PSU output?
 
From a quick bit of research, the original PSU is rated 80W, and will run two Rack3 systems - so no more that 40W for one, if that is what you have.

1A each for the +/-16V and +24V should be adequate. I'd expect the +48V to be for phantom power, so a fraction of an amp.
 
I'd use a separate dual 15V (or15-0-15) transformer for the +/- 16V, and linear voltage regulators, for a low noise audio system.

A dual would 24V transformer (or 24-0-24) can then be used for the 24V and 48V outputs, again with linear regulators. Basically, that could be a "floating" +/- 24V, with the most negative 24V out as 0V.

Do you have the current requirements for each PSU output?
Seems like a great idea, as it is the approach that will produce the least noise, currently the total current for all rails is 300mA and for the whole setup it'll draw around 2 amps max here are some numbers "
Total Current Requirements:
  • +16V Rail: 720mA
  • -16V Rail: 720mA
  • +24V Rail: 360mA
  • +48V Rail: 120mA
 
From your schematic, it is not clear whether your toroidal transformer has 2 electrically separated 24 volt windings. If it it is a NO, then this setup will blow up the bridge rectifiers / transformer or both.
If it is a 24-0-24 volt winding, then a single bridge will give both +ve and -ve voltages. You don`t need 2.
Use 3 +ve voltage buck convertors and 1 -ve voltage Buck Convertor for the outputs.
 

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