AC Voltage multiplier

[thone]

Dear all,
Anyone help me please. How can I multiply VAC six time? I try voltage doubler but the output is VDC. I want VAC as an output. My input is +-12VAC. My circuit doesn't consume much current (about 80mA). I don't want to use transformer since it makes my circuit bigger.

Thank you

 

[Sebi]

Without transformer can't do this...

 

[mechie]

AC multiplier ?

Can't you use a normal (DC) multiplier and chop the output to give a sort of square wave?

 

[thone]

you mean, use V multiplier and the chop it by FET or TR? if I do this, is power loss higher than using Tranformer? Thank you for ur help

 

[kinjalgp]

Certainly not. Effeciency will be better than transformer since no copper or iron losses are present. Also you are not wasting any power but allowing only required power to be delivered to load using electronic switch.

 

[stevez]

My general understanding of transformers is that they are reasonably efficient. I do not want to insult you but have to ask if you realize that power in equals power out minus any inefficiency. In a system that is at or near 100% efficiency the multiplication of the voltage by 6 will result in a current of 1/6 the input current. 80 ma/6 = 13.3 ma. If you've considered that then the next question would be - how efficient does the "transformer" have to be if a normal transformer is not sufficient?

 

[kinjalgp]

To my knowledge iron-core transformers are 80-85% effecient while switching circuits are upto 96% effecient.

I didn't mention that transformers are higly ineffecient but comparably switching circuit has better effeciency than transformer.

 

[Jaw174]

if its only pulling 80 Ma, then use an itty bitty audio transformer. just look inside a disposable flash camera, they haev transformers that step up the voltage to 300 volts.. very simple... what is the final voltage u desire, and for what purpose?