• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

**need help with AC to DC and DC to DC power supply TT**

Status
Not open for further replies.

ahdehling

New Member
first of all, i think i shall intro myself! hi all, im Adeline :D nice to meet you all :) im a newbie in engineering and im in a project of making a DIY 2.1 speaker, and im in charge of the all powerful power supply :p

ok back to project *dies* i will try to give as much details as i can so help a poor newbie please ><

like i say, i need to design a power supply for a 2.1 speaker. I need a AC to DC and DC to DC circuit :(

AC to DC
Input Voltage: 230-240Vac
Output Voltage: 14.2Vdc
Power needed: 50W
Current: 3.5A

transformer > full wave recitifer > shunt regulator[a resistor + zener diode] > output [more or less what i plan to use for the circuit]

I dont know what else is needed..but i need to design the circuit, with what is needed, and the value of each parts [like the value of resistor and etc].:eek:

DC to DC
Input Voltage: 18.5Vdc
Output Voltage: 14.2Vdc
Power and Current: 50w and 3.5A

Im thinking of using a buck converter IC but Im unsure of how the ic works.. and what else is needed..:confused:

please try to help me as much as possible >< [and fast too TT]

thanks all for reading :D
 

Optikon

New Member
ahdehling said:
first of all, i think i shall intro myself! hi all, im Adeline :D nice to meet you all :) im a newbie in engineering and im in a project of making a DIY 2.1 speaker, and im in charge of the all powerful power supply :p

ok back to project *dies* i will try to give as much details as i can so help a poor newbie please ><

like i say, i need to design a power supply for a 2.1 speaker. I need a AC to DC and DC to DC circuit :(

AC to DC
Input Voltage: 230-240Vac
Output Voltage: 14.2Vdc
Power needed: 50W
Current: 3.5A

transformer > full wave recitifer > shunt regulator[a resistor + zener diode] > output [more or less what i plan to use for the circuit]

I dont know what else is needed..but i need to design the circuit, with what is needed, and the value of each parts [like the value of resistor and etc].:eek:

DC to DC
Input Voltage: 18.5Vdc
Output Voltage: 14.2Vdc
Power and Current: 50w and 3.5A

Im thinking of using a buck converter IC but Im unsure of how the ic works.. and what else is needed..:confused:

please try to help me as much as possible >< [and fast too TT]



thanks all for reading :D
On the AC-DC, using a resistor and shunt zener regulator and expect to deliver 50W, 3.5A? You might want to re-think that part of the design.

Consider instead an LM317, several outboard pass transistors (~1A each) and a large heatsink to bolt everything onto.
 

Blatman Bond

New Member
Im new here, new members.

OK!. Hello adeline, nice to meet you.:p :D

Let's start with AC to DC.
It's nothing with transformer and rectifier. But you'll need any power transistor with attached heatsink to dissipate power.
Sorry with the value, please design it 1st. So I can help.

Now, buck converter.
All that you need is read any buck converter articles, you may ask me which part you don't understand. Typically they collect current from input voltage to inductor and convert it back to output voltage. Charge and discharge. You need to know about Inductor 1st, where V(L)=L*dI(L)/dt.
 

k7elp60

Active Member
Both power supplys could use an LM338 as a regulator as it will safely handle
5A.
 

Thunderchild

New Member
do you actually need a regulated power supply ? most power amps can run on a simple full wave rectifier followed by a smoothing condenser (that you forgot to mention and is essential),

if you want to smoth it a bit more without too much complication use a LC filter but I'm not an expert in those
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top