AC Power Supply Question

[nicksydney]

Hi,

Currently I'm reading on about power supply (AC to DC converter power supply) and most of the articles I read identify the usage of bridge rectifier to convert to DC, my question is if I don't want to convert to DC but leave the output as still AC is it correct to say that I don't need to use bridge rectifier ?

Thanks

 

[gerty]

If you want an ac output you cannot use a bridge rectifier.
You load must be compatable with ac voltege in order to get any use from it.
In this case you are just using a step down transformer.

 

[dr pepper]

If you want a variable ac supply, look at using a variac transformer, do a google.

 

[KeepItSimpleStupid]

Take a look at the rectifier design guide on this page: http://www.hammondmfg.com/5cpwr.htm and some of the other info.

 

[nicksydney]

Thanks a lot all. I want to do this is to get sine waveform which from reading is only possible by using AC so if I build this kind of circuit is it the right way to obtain sine waveform ? or there is an easier way for this ?

Cheers

 

[KeepItSimpleStupid]

Mains frequency is usually 50 or 60 Hz. Aircraft may use 400 Hz.

There are other ways to generate different frequencies with a sine shape. One method is this: https://en.wikipedia.org/wiki/Wien_bridge_oscillator

These designs have very little power, but can be amplified in both voltage and current using a power amplifier circuit.

 

[dr pepper]

There are various standard ac supplies around, aircraft as mentioned which is often 3 phase, also lighting and professional power tools sometimes have a higher freq ac supply.

If you want as simple as possible variable voltage mains fre (50/60 hz) supply then the variac is the easiest option, you can synthesize ac as done in variable frequency motor drives, this can be quite complex though. Another way you could generate various kinds of ac waveforms is to use an audio power amp, this does limit the voltage and max freq though.

 

[ChrisP58]

What is it that you are trying to power?