# Need help with inverter circuit

#### desoky675

Joined Sep 18, 2011
1
I've been searching for a sine wave inverter,that takes 12 v DC car battery to 220V AC with about 100W power, but all the circuits that I've found has square wave output. I need it to power a computer speekers .
http://www.eleccircuit.com/inverter-100w-by-ic-4047-2n3055-with-pcb/

my first question is , will the square wave be able to pass through the transformer.
And if it passes , will it be good for the speekers.
And is there a simple way to produce a full sine wave at the same power rating.

thanks

#### Wendy

Joined Mar 24, 2008
23,320
I've been searching for a sine wave inverter,that takes 12 v DC car battery to 220V AC with about 100W power, but all the circuits that I've found has square wave output. I need it to power a computer speekers .
http://www.eleccircuit.com/inverter-100w-by-ic-4047-2n3055-with-pcb/

my first question is , will the square wave be able to pass through the transformer. Yes, this is not a sine wave inverter. The waveform will be somewhat rounded by the transformer, but they will have the basic square shape.
And if it passes , will it be good for the speekers. Depends, you didn't include all the info. I assume the inverter is powering an amplifier? That depends entirely on the amplifier and it's internal filtering. It would probably work.
And is there a simple way to produce a full sine wave at the same power rating. Simple? No, but it is doable.

thanks
Work in progress...

AC/DC Inverters

#### Audioguru

Joined Dec 20, 2007
11,248
Each TIP122 darlington driving the two 2N3055 power transistors produce a voltage loss of about 2V. Then the 12V winding of the transformer gets only 10V peak instead of 12V peak. The 220V output from the transformer will have an average and peak of 183V.
The much higher peak voltage of the sine-wave from the mains which is 311V.

But the amplifier of the computer speakers depends on the 311V peak from a sine-wave so the 183V peak (the voltage is much too low) square-wave from the simple inverter probably will not work.