Cheap smps base on TL494 pwm, half bridge AC-DC

norazmi

diysmps Senior Member
Hi all,

Im Nor Azmi from Malaysia, here i will share something regarding smps using TL494 chip and trafo drive r EE16 ( u can take it out from PC PSU ), i think it would be cheap to build and with easy parts. Owner of this creator from Forosdelectronica website claims that it can deliver at least 300 watts, i dont know if it can take more power, maybe some of us here willing to help, im gonna setup this one and let you all know the progress.

here is the schematic.
 

Attachments

  • SMPS Half Bridge Compacta - Esquema.pdf
    26.4 KB · Views: 3,742

norazmi

diysmps Senior Member
Windind trafo: EI33

Primary : 26 laps ( 13 +13)
Secondary : 22 laps ( 11+11)
secondary for 15 volt : 4 + 4 laps

inductor : 40 laps x 2

for the driver u can use from old pc supply, i`ll take some picture here the core name is EE16, must watch the trafo leg combination and i`ll explain. hope we can share together.
 
Last edited:

norazmi

diysmps Senior Member
i`ll start build this baby on 3rd jan, because some of part not arrive yet and i lost my drilling machine, lol, tomorrow i`ll buy new one.
 

tebci

New member
ive got my drill yesterday, buy new one hehehehe, so i`ll start today for this project :D

You will show how to wind transformer?

This is very good project for DIY like me who cant get ETD transformer to make the SMPS, I think many people will make this SMPS is you show success. and me will be first one
 

norazmi

diysmps Senior Member
tebci, yes, i`ll show it. for EE16 u can just take it out from old psu. i`ll show the leg combination for EE16 core, how to connect it to the board, for the main trafo also i`ll show it here and we can share with others, and will discuss more about it. Thanks.
 

norazmi

diysmps Senior Member
Main trafo winding info:

for the winding instruction i already mention above, and this is the drawing.

primary winding, "m" to "n" 13 laps, and "n" to "o" 13 laps,

secondary , "q" to "r" 11 laps and "r" to "s" 11 laps.

third secondary, 4+4 laps "t" to "u"
 

Attachments

  • Conexión bobinados.jpg
    Conexión bobinados.jpg
    93.2 KB · Views: 935
Last edited:

norazmi

diysmps Senior Member
EE16? i dont get what u mean...

mike, yes it is, there is feedback with 100k trimpot + 6.8k resistor..
 

mikecarel

New member
great.. hope to hear from you about this circuit. This is a typical tl494 regulated smps circuit i'm looking for. I'll try to build one myself as a start. I'm just completing all necessary information and materials specification(transformer, transistor etc.).

Thanks.
 

norazmi

diysmps Senior Member
yes this is the basic smps with TL494 pwm, EE16 driver trafo u can get it from old psu. for 300w u can take core from old psu EI 33-35 will do. :D output transistor can be mje13007 or more power for mje13009.
 

mikecarel

New member
Windind trafo: EI33

Primary : 26 laps ( 13 +13)
Secondary : 22 laps ( 11+11)
secondary for 15 volt : 4 + 4 laps

inductor : 40 laps x 2

for the driver u can use from old pc supply, i`ll take some picture here the core name is EE16, must watch the trafo leg combination and i`ll explain. hope we can share together.

I'm just confused with this tranfo winding. I've read the discussion about this in Forosdelectronica website, and it was different from yours, though i'm just reading it via google translate and it was like this:

Main Transformer - Core EI33 and the like:
--------------------------------------------------

- Primary: 26 turns (13 + 13) - 6 wires AWG29
- Secondary: 11 + 11 turns - 8 wires AWG29
- Tertiary: 4 + 4 turns - 1 wire AWG24


Construction Trafo:
-----------------------

- Middle Primary between "m" and "n".
- Insulating layer of copper foil (do not close, and does not form a loop), weld in "P".
- Secondary in parallel (both arms at once), a branch between "q" and "r", the other between "r" and "s".
- Insulating layer of copper foil (do not close, and does not form a loop), weld in "P".
- Middle Primary between "n" and "o" (in the sense that primary bovine anterior half!).
- Tertiary in parallel (both arms at once), a branch between "t" and "r", the other between "r" and "u".

I was confused in secondary and tertiary winding instructions.... Hope someone can clarify this further.

Thanx
 
Last edited:

norazmi

diysmps Senior Member
Hi mike ,

There is no mistake, the different just my typo for the Tertiary, so i write it as secondary +/- 15v as it should be write as Tertiary. Secondary still 11 + 11 laps means 22 laps in total.
 

mikecarel

New member
Yes, there's no separate supply for the tl494, it's just like an aux supply that will came to the main trafo. You can also separate the supply of tl494 if you like.


Mike
 
Top