high frequency inverter - sinewave ?

Thread Starter

youdontknowme

Joined May 30, 2017
11
Hi,

I'm planning on making a high frequency inverter that is able to produce sine wave. This is for wireless power transfer with a load of 12vdc at the receiver side.

Transmitter side :
Input of the inverter will be 12VDC. Then 555 timer will be used to create 100khz squarewave.

How do i make it to sine wave ??
 

ScottWang

Joined Aug 23, 2012
6,826
Square wave through two stages of RC filters will be become sine wave, but the amplitude will be smaller, so you need to amplifying the sine wave to the amplitude you want.
 

BobTPH

Joined Jun 5, 2013
2,025
You can feed the square wave directly into a series LC tuned circuit where the L is the coil used for transmitting the power. It will turn into a sine wave.

Bob
 

Thread Starter

youdontknowme

Joined May 30, 2017
11
Square wave through two stages of RC filters will be become sine wave, but the amplitude will be smaller, so you need to amplifying the sine wave to the amplitude you want.
how do i calculate the values of the RC needed in the 2 stages ?? say for 150khz square wave

You can feed the square wave directly into a series LC circuit where the L is the coil used for transmitting the power. It will turn into a sine wave.

Bob
how do i calculate the values of LC needed for 150khz square wave ?
 

BobTPH

Joined Jun 5, 2013
2,025
If you want to design circuits, you should know how to do that. Look up the formula on Google.

Bob
 

ScottWang

Joined Aug 23, 2012
6,826
You can feed the square wave directly into a series LC tuned circuit where the L is the coil used for transmitting the power. It will turn into a sine wave.

Bob
I tried the LC filter before, but the output amplitude of positive and negative is unbalance, so it needs to through op amp to adjust, maybe you have a better solution.
 

DickCappels

Joined Aug 21, 2008
5,886
upload_2019-10-12_0-51-47.png

This is a keyed 187 kHz transmitter. You can leave out the 1N4148 and the related 4.7k resistor. It makes beautiful sine wave currents at the carrier frequency.

Use your own tank circuit and get rid of the LED and 100 ohm resistor.

Scaling will be needed to get up to 10 watts.
 
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