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Determining components of converter DC-DC

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byakuya

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I want to make a converter 24 volt DC to 12 volt DC..
I have problem in determining spesification or value of components below :

- diode
- capasitor

I use 7812 IC regulator in electronic circuit that i attach here

84_1318170980.gif


**broken link removed**

Can anyone help me please? :-|
 

From where inputs are coming? are you using half wave rectifier ? diode value can be 1N4007 first capacitor 1000uf 50v second one 100uf 50v or 10uf 50v
hope your problem will be solved.
 
your project will NOT work if you have too much current
the 7812 will dissipate too much heat and shut down itself
you MUST use a switching regulator ic like a LM2576
datasheet here : **broken link removed**
 
input source of electronic circuit above comes from 24 DC , so, the scheme is :

AC 220 -> DC 24 v adapter 0,7 A -> 24 to 12 converter circuit -> expected output (DC 12 volt) -> Load (12 volt 0,7 A)

i just try to make a simple converter,
so, is my project wrong?
thank you
 

0,7A load, 12v of voltage drop...
that makes 8,4W of power to dissipate
definitely way too much for a poor 7812 ...
 

if you can use lm317 instead of 7812 . it will be better.
you may have to use heat sink for 7812
 

the lm317 in a to220 package has a thermal impedance of 23°/W
so it has still 8W to dissipate and will heat of about ... 190° ... nice to have it in winter ...
 

I'm actually a beginner in this field ..
if I use the LM317 or LM2576, should I add the other components in my project?

Can I still use my scheme in my converter as shown in the picture, or whether there are changes that I should do?

78_1318302941.gif


thank you ...

---------- Post added at 10:19 ---------- Previous post was at 10:16 ----------

NB : 7812 is replaced by LM317 or LM2576 in image,
 

Make it with 7812
when you learn a little about electronics then you can make smps supply using MC34063.
 

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