# Help with voltage doubler

Discussion in 'General Electronics Discussion' started by Young, Feb 8, 2013.

1. ### Young

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Feb 6, 2013
I studied this circuit through the whole night but i dont get a single thing of how it doubles a voltage,please am a noobie or novice if i make mistake please dont insult just correct me i believe you are knowledgeable than i am thats why i registered so i could gain knowledge ok...from what i understand the capacitor charges because its connected to d negative left side directly why the positive charge pass through the diode to the positive side of the capacitor thus enabling it to charge then later releasing it from what i see thats the only thing i can guess,i have googled for more than 5hr all they tell me is there is a clamping etc i dont understand pls help

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2. ### davennModerator

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Sep 5, 2009
HI,
I will leave some explaining to others...
BUT just one thing ... Can you please use proper text/spelling
PLEASE DONT use text messaging shortened words .... it makes it really difficult to understand what you are saying

Dave

3. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
You're not the only one confused. Look here.

4. ### Laplace

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Apr 4, 2010
Think of the diode as a switch. For half of the power cycle it is closed, for the other half it is open. When Vin is negative the diode is forward biased (closed), no current flows through the load (shorted by the closed switch), and the capacitor becomes fully charged (minus left, positive right). When Vin goes positive the diode is reverse biased (open), the fully charged capacitor reinforces Vin and this double voltage appears across the load. So what would happen if the load were a capacitor?

5. ### duke37

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Jan 9, 2011
This is not a voltage doubler, it is a method of shifting the average voltage using the diode as has been said. To get a voltage doubler, you need a diode on the output, feeding into a reservoir capacitor.

You can use more than one stage - see Cockroft-Walton multiplier - to generate vast voltages.

6. ### Young

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Feb 6, 2013
i have adjusted the spellings ok now explain

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Nov 17, 2011

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9. ### Young

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Feb 6, 2013
Its like no one understand how it works,because i have not gotten any answers except from luke and laplace,some people are telling me to click on a wikepedia page,i have gone there but i dont understand,if anyone understand just explain it to me they way you understand.some people say the picture is not clear ok let me upload another one.

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10. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
I'm afraid you can't just blame us.

You're going to have to look at those links or read the explanations. Where you can't understand you'll have to point us to exactly what you don't understand so we can explain more clearly.

Yes that picture is clear. It's also a different circuit.

But it's easy to understand.

Positive half cycles charge the top capacitor. Negative half cycles charge the bottom capacitor. The output is across both capacitors which is therefore at twice the peak voltage of the input

11. ### Miguel Lopez

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Jan 25, 2012
And don't use the term "some people". We have names (nicknames at least)

12. ### Young

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Feb 6, 2013
Ok,ok sorry if i have offended you steve and miguel lopez and thanks steve for the explanation i really appreciate it

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Feb 6, 2013

14. ### davennModerator

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Sep 5, 2009
you just leave the thread as it is

Dave