Question

[laze5]

First of all i aint good at english,and im going to ask how DC to DC converter looks like in psu and where is located with picture

 

[Average Nerd]

Unless stated otherwise, most (computer) PSUs don't have DC to DC converters.

[Somerandomtechyboi]

Just now, Average Nerd said:

Unless stated otherwise, most (computer) PSUs don't have DC to DC converters.

unless they accept dc input

 

i think pico psus are literally just dc dc converters that convert 12/19v dc to 12v 5v and 3.3v hence why theyre so small

[DreamCat04]

3 minutes ago, Average Nerd said:

Unless stated otherwise, most (computer) PSUs don't have DC to DC converters.

Internally they do. How would they get all their different voltages if they didn't have DC to DC converters? DC-DC converters just consist of some transistor to switch on and off some voltage and a capacitor afterwards to smooth out the voltage

[Average Nerd]

4 minutes ago, DreamCat04 said:

Internally they do. How would they get all their different voltages if they didn't have DC to DC converters?

I thought the ferrite transformer is responsible for producing the different voltages through the means of center-tapped windings.

5 minutes ago, Somerandomtechyboi said:

unless they accept dc input

Most do (theoretically at least), because the first part of all the ATX units I have taken apart was a rectifier that produces the DC for the switching circuit (that produces high frequency sqare waves AFAIK)

[laze5]

can somebody draw me where are they located? and what are they symbols?

[RollyShed]

32 minutes ago, laze5 said:

First of all i aint good at english,and im going to ask how DC to DC converter looks like in psu and where is located with picture

 

The AC voltage from the wall (the mains supply) that goes into the power supply is rectified so it is now DC at a reasonably high voltage. If the input is 230 VAC then the DC is near 300volts. This is fed to an oscillator driving a transformer at high frequency. The output is low voltage AC. This is rectified so there is now low voltage DC. There is usually some feed back (optical for electrical isolation) so the whole system is stable as far as the output voltage with varying loads.

 

High frequency and a ferrite transformer allow everything to be physically small.

 

If you have to ask, a picture isn't going to inform you of what is happening or how it happens. If you want to see the components, simply take the cover off a power supply, 4 screws. If you want a circuit diagram, Google it.

[RollyShed]

Here is a link to a circuit diagram and description -

https://www.smpspowersupply.com/atx-power-supply.html

 

https://www.instructables.com/A-Makers-Guide-to-ATX-Power-Supplies/

[Spotty]

58 minutes ago, laze5 said:

how DC to DC converter looks like in psu and where is located with picture

DC-DC converters are typically on a daughter board located towards the output side of the power supply. After the main transformer and before the cables/modular panel. Normally consists of a couple of FETs to handle voltage conversion, controller, a pair of inductors, and some polymer caps. Will vary slightly depending on the power supply. Usually pretty easy to spot, just look for the board with inductors on it near the output side.

 

If you check power supply reviews they'll often have photos of teardowns of the power supply and list the key components.

 

Images pulled from https://hwbusters.com/psus/xpg-kyber-850w-psu-review/3/

 

https://www.tomshardware.com/reviews/corsair-rm850x-v2-psu,5568-3.html

 

 

Edit: I should clarify, this is for DC-DC conversion for 5V and 3.3V in an ATX power supply. I'm assuming that was what you were referring to when asking about DC-DC conversion in a power supply since that is what PSU marketing material refers to when they state a power supply has "DC-DC conversion".

Edited May 14, 2024 by Spotty

[laze5]

Quote

If you want to see the components, simply take the cover off a power supply, 4 screws

thats what i want it,i see spotty already done it so never mind,about the diagram i ll see what i can understand from google

because google sometimes leads me to wrong directions

[Somerandomtechyboi]

46 minutes ago, Average Nerd said:

I thought the ferrite transformer is responsible for producing the different voltages through the means of center-tapped windings.

Most do (theoretically at least), because the first part of all the ATX units I have taken apart was a rectifier that produces the DC for the switching circuit (that produces high frequency sqare waves AFAIK)

so basically remove the ac part and hook it up to dc and now youve got a dc to dc converter?

 

i really should learn abit about circuits like this especially since i wanna play with physical modifications on my boards like voltmod for stuff like 3v+ ddr3 or jus being able to adjust voltages on the fly rather than having to go into the bios all the time

 

24 minutes ago, Spotty said:

Edit: I should clarify, this is for DC-DC conversion for 5V and 3.3V in an ATX power supply. I'm assuming that was what you were referring to when asking about DC-DC conversion in a power supply since that is what PSU marketing material refers to when they state a power supply has "DC-DC conversion".

i was wondering why the thing looked so dinky and small

 

where does the 12v conversion happen then?

 

id be pretty interested in making my own pico psu since there arent really any high power ones in my country and if they are theyd probably be overpriced, i mean it is just dc to dc conversion so no need to deal with ac voltage

[Average Nerd]

4 minutes ago, Somerandomtechyboi said:

so basically remove the ac part and hook it up to dc and now youve got a dc to dc converter?

Just connect the external DC to the AC pins on the rectifier, so you don't have to worry about polarity.

[RollyShed]

8 hours ago, Somerandomtechyboi said:

so basically remove the ac part and hook it up to dc and now you've got a dc to dc converter?

NO.

 

You need to learn a bit about electronics and how things work.

 

All of those saying DC-DC converter are missing out half of the circuit.

 

Firstly, mains supply AC goes into the power supply. This is rectified so it is high voltage DC.

A high frequency oscillator, two transistors in push-pull run the transformer at high frequency so the core has to be ferrite, not the usual iron laminates on low frequency transformers. The output from the transformer is obviously AC but at  lower voltages, multi-winding and these windings go to different rectifiers (to give DC) and regulators to give the different voltages required. As said before, feed-back regulates the output voltage by controlling the first lot of transistors.

 

NOTE - multiwindings so various, a range of, output voltages from the transformer going to their rectifiers and regulators.

 

Transistors - they could be MosFets, depending on the design.

 

Obviously your "remove the ac part and hook it up to dc" comment shows a total lack of understanding of electronics.

Do you know what a diode is?

Do you know what a resistor is?

Do you know how a transistor works?

Do you know how a transformer works?

[laze5]

 

On 5/14/2024 at 12:58 PM, Spotty said:

Normally consists of a couple of FETs to handle voltage conversion

correct me if im wrong i dont think transistor can convert electrical signal,and i've contact techician guy