SMPS Design 220V AC TO 12-0-12V AC 65KHZ 20W
by rupjit81 in Circuits > Electronics
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SMPS Design 220V AC TO 12-0-12V AC 65KHZ 20W
In this document I'm demonstrating how to design SMPS with 220v AC to 12-0-12 V 65khz and power handling of 20W.
The operating frequency is 65 Khz.
Im using IC TL494 as oscillator.
please follow the transformer design and circuit diagrams. For component list refer supplies section.
Supplies
Bill of materials
C1 22PF
C2 220uF/400v
C3 47uF/400v
D KBL04 Bridge
D1 12V 1W
D2 SCOTTKEY DIODE
J1 ANY
L1 Line filter
Q1 25N120
R1 100K
R2 100K
R3 100K
R4 100K
R5 10K
R6 47k 5w
R6 820E 5W
R6 47K 5W
R7 47k 5w
R8 330E 1W
R9 47k 5w
R10 100E 1W
R11 30W LAMP
R11 100K 1/4W
R11 10K 1/4W
T1 FERRITE TRANSFORMER
U1 TL494
Construction
Please follow the circuit diagram for Contruction.
The circuit uses 220V AC supply and makes it DC. There is a risk of electrical shock.
Please refer to the videos attached.
TL494 is designed to generate a fixed frequency of 65khz.
The Circuit will take power from 230 V DC line initially and later on the Aux winding of the transformer will feed power to the circuit.
To power up the TL494 and to drive the IGBT gate resistance R6,R7,R9 all 47k 5W are connected in parallel. 12V zener diode D1 maintains the voltage from aux winding to 12 volts.
IGBT 25N120 is used as a switching device.
The oscilloscope response is added as image file as a reference.
Transformer Design Data
Transformer design data
Input 220V AC 12-0-12 V AC output @ 20W
Primary winding design
Vin = 230V DC input voltage
Npri = No. of primary turns = (Vin*10^10)/(4*frequency Hz*flux density Gauss*Core area sq.mm)
= (230*10^10)/(4*65000*1500*69)
= 85.47 turns or 85 turns
Auxiliary winding design
Aux. winding voltage Vaux = 12V * 1.414 (p-p)
= 16.98 V
No. of Aux. turns = (Vaux/Vin)*Npri
= (16.98/230)*85.47
= 6.30 turns = 6 turns
Secondary winding design
Sec. winding voltage Vsec = 12V * 1.414 (p-p)
= 16.98 V
No. of Aux. turns = (Vsec/Vin)*Npri
= (16.98/230)*85.47
= 6.30 turns = 6 turns
Wire size = 32 SWG
Current capacity = 100 mA
Primary power = 230V*0.1 A = 23 W
Secondary winding is center tapped.
Secondary current = 23 W / (12 V + 12 V) = 0.95 A
0.95/0.1 A = 9.58 conductors say 10 conductors.
1 more conductor for aux. winding.
Conclusion
Make circuit as per diagram.
Make transformer as per diagram.
The circuit uses 220V AC supply and makes it DC. There is a risk of electrical shock. Please don't perform this experiment if you are not aware of AC and DC 220V characteristics. Parts of this circuit is not isolated from mains and hence there is risk of electric shock.