# AC/AC Converter

1. Aug 14, 2011

### kahei

I would like to ask how to change the frequency of the ac supply (frequency = 50Hz) to a ac with a very high frequency. Does anyone suggest any materials or websites for me to reference? Thanks.

2. Aug 14, 2011

### vk6kro

You would pass the 50 Hz AC through a suitable transformer then rectify the output and filter it to get a DC voltage. DC voltages in the range 12 to 50 volts are commonly used for this.

Then you would use this DC voltage to power an oscillator which produces output at the required frequency.

This signal could then be amplified in an amplifier to produce sufficient output for your purposes.

3. Aug 15, 2011

### yungman

Look up schematics of online switching power supply.( the kind that plug into wall plug and give you DC output). It consist rectifiers that turn 110VAC from the wall line and power an oscillator at something like 50KHz to form a switching power supply. Just copy their circuit. This is very common circuits, you can find books on switching power supplies.

4. Aug 16, 2011

### EducationalC

I've been on PF for about 10 minutes and I've already seen 2 past issues that I hired a Boston electrician to complete because I didn't know about sites like this.

What yungman said is exactly right. The circuits are extremely common, and a switch is probably the best method.

If you need some more help, let us know!

5. Aug 23, 2011

### kahei

Do you mean that I should first convert the a.c. (e.g. 220V ac) to d.c., then connect it to the oscillator circuit? Would the output of d.c. be too high?

Beside, may you please give me some links for me to have some references?

Thanks a lot.

6. Aug 23, 2011

### vk6kro

You said VHF, very high frequency. This is usually taken to mean frequencies above 30 MHz and below 300 MHz. Did you mean this?

You didn't say what voltage you want, but you could step the input voltage down to 12 volts, rectify and filter it and then run an oscillator from that. Or, you could step the output of a VHF oscillator down to whatever voltage you want.

Components for 12 volt oscillators are probably cheaper and more readily available than for 220 volts.

7. Aug 23, 2011

### yungman

Far as technical information, just go online and find the theory of operation of an "On line switching power supply" and you'll should find a lot of info. They have books on how to design a switching power supply........which is a AC to DC converter in essence. Inside, it has an about 50KHz oscillator that get rectified to become DC. Just take the oscillator output.

Last edited: Aug 23, 2011