200 WATT INVERTER 24V DC TO 220 V AC @ 65KHZ

In this writeup I'm demonstrating 200 W inverter with input voltage 24 V and output voltage 240 V AC with operating frequency of 65KHZ. The circuit is loaded upto 200 Watt.

BILL OF MATERIALS

C1 22PF

Q1 IRF840

Q2 IRF840

Q3 25N120

Q4 25N120

Q5 25N120

Q6 25N120

Q7 25N120

Q8 25N120

Q9 25N120

R1 100K

R2 100K

R3 100K

R4 100K

R5 10K

R6 10K

R7 330E 1W

R8 330E 1W

R9 100E 1W

R10 100E 1W

R11 10K

R12 4.7K

R13 4.7K

R14 1k

R15 1k

R16 4.7k

R17 10K

R18 1K

R19 10K

R20 1K

R21 10K

R22 10K

R23 10K

R24 10K

R25 10K

R26 10K

R27 200WATT 230V LAMP

T1 PULSE TRANSFORMER

T2 MAIN TRANSFORMER

U1 TL494

This circuit is intended to deliver 200W power with 24 V DC input and 240 V ac output.

The circuit uses IC TL494 as an oscillator. The oscillator generates 65 khz.

The output is taken from PIN 9 and 10 and fed to mosfet IRF840. The output drives a pulse transformer. This transformer generates 12 V Ac @ 65Khz

The secondary of pulse transformer is fed to gate of IGBT banks 1 and 2.

The IGBT bank 1 and 2 drives transformer T2. T2 is the main power transformer.

IGBT 1 and 2 are 7 IGBTs in parallel.

The circuit is tested with 200Watt lamp.

Please watch the video for the reference.

Pulse transformer T1

No. of turns in primary = (12*10000000000)/(4*65000*69*1500) = 5

Core area of selected core = 69 sq. mm

Input voltage = 12 V DC.

However in tested circuit supply voltage is 17 V Dc.

Primary and secondary are 5 turns each center tap winding in primary and secondary.

Main Transformer T2

Supply voltage = 24V Dc

No. of turns in primary = (24*10000000000)/(4*65000*228*1500) = 2.69 turns or 3 turns.

For an option of 12 V we need a center tap winding.

Then for a center tap it needs 1.5 turns.

It is difficult to make 1.5 turns , so we make 2 + 2 turns as center tap.

So for 24V DC we have 4 turns (2 +_2 center tap)

Secondary voltage = 220* 1.414 = 325 V

Secondary no. of turns = (325/24)*4 = 54.16 or 54 turns.

so Secondary is 27 + 27 turns center tap winding.

Wire used = 23 SWG. (Current capacity = 0.584 A)

For 200 Watt 200/24 = 8.33 A

No. of conductors secondary= 8.33 A / 0.584 = 14 conductors 23 swg

Primary = 200/220 = 0.909

No. of conducors primary = 0.909 / 0.584 = 1.55 or 2 conductors 23 swg.

The circuit involves 220 V AC power. So care must be taken while making.

The circuit may be used as a reference.