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[on:]

Hello,

I am new to the world of electronics, and I find it fascinating, but confusing.  I am have done many of the examples in the Arduino tutorials and they are very helpful.  Now I'm trying to go from a schematic to board layout for a Voltage Doubler and am having hard time getting this one right.  Each attempt yields one of two results, either: a) a dead/incomplete/incorrect circuit (0 Vout) or b) vOut = vIn.

I have picked what looks like a simple example:

Voltage Doubler @ http://www.coolcircuit.com/circuit/voltage/

If someone could provide a picture of what the board layout would look like for the Voltage Doubler @ http://www.coolcircuit.com/circuit/voltage/ I think I may be able to move on to the Voltage Tripler and then on to the Voltage Quadrupler.

I know there are IC's that do this, but I wouldn't be learning how to translate schematic to circuit board.

Attached is the schematic of the Voltage Doubler I am trying to create on a bread board using an Arduino for Vin.

Guidance is much appreciated.

Thanks,
-Mike

[Reply #1 on:]

Hi Mike,

Glad to see you are really experimenting and not just hooking up stuff other people designed.

The circuit you show is based on the the idea that the INPUT to it is constantly being switched between V+ and Ground or common.

So just take the BLINK example, change the delays to about 1/100 of a second (10 ms) and connect that output pin to your circuit.

BUT (There's always a but in electronics, it seems) Look closely at the first two circuits on CoolCircuit.

 - The first one has outputs that are NOT connected to either Arduino +5 or Ground, but are 'floating'.. and you would have to measure the voltage between those two isolated points.

  - The Second circuit (Cascade) DOES have a common ground with Arduino ground and should put out +10 Volts relative to ground.

To really understand what these circuit do, it Would BE Great to have or borrow an oscilloscope to see the waveforms. Maybe you can bring your whole Arduino and Circuit in to a school / university / business Lab. I bet guys would help you, and you'd make some good (people) connections.

But keep on working through the "not working" frustrating times.  Some of us have worked on stuff like this for WEEKS and not gone (to us) crazy in the process.

[Reply #2 on:]

Each attempt yields one of two results, either: a) a dead/incomplete/incorrect circuit (0 Vout) or b) vOut = vIn.

What voltage are you feeding into it? This circuit will only work if you feed it an AC signal. They won't work if you just feed a DC voltage into them.
If you want to use a circuit like this (it is called a diode pump) from DC the you have to make it into AC first by making an oscillator and driving this circuit with the oscillator. The oscillator has to have complementary outputs, that is when one is high the other is low.
As you say there are chips that do this. Note however that the current you get out of circuits like this is quite small, in the region of several tens of mA at most.

[Reply #3 on:]

Thanks.

I didn't realize the input was AC, and after reading more - I'm not ready to mess around with AC yet.

I think for now I'll play around with this: Darlington transistor (http://en.wikipedia.org/wiki/Darlington_transistor)

-Mike

[Reply #4 on:]

not ready to mess around with AC? its not going to bite you or anything

[Reply #5 on:]

You can just drive the Cascade circuit from an Arduino pin. A PWM pin set to 128 would be good... and no code once setup.

This is a good possibility for some analog circuit that would run well on +10 volts..

[Reply #6 on:]

Thanks Terry,

I'll give the Cascade circuit a try.

-Mike

[Reply #7 on:]

Hey, look at this:

http://www.cutedigi.com/product_info.php?cPath=284&products_id=4426&osCsid=6c8f117cf1b4110769ac941f3986803c

Look like a familiar circuit?? 

-5, -10 and +5 from 2 Arduino pins...

So it IS pretty practical 

[Reply #8 on:]

Putting an arduino output directly into a 47uF capacitor will take the peak current above the maximum 40mA limit at the start of each cycle. I wonder how long before the arduino dies?

For safety you should add a series resistor of 100R, better still drive it with a transistor.

[Reply #9 on:]

Hey, look at this:

http://www.cutedigi.com/product_info.php?cPath=284&products_id=4426&osCsid=6c8f117cf1b4110769ac941f3986803c

Look like a familiar circuit?? 

-5, -10 and +5 from 2 Arduino pins...

So it IS pretty practical 

Looks interesting, nice low price also. No sketch provided. I assume you could just run a PWM 50% signal on pin 10 used. However the pin 13 used is not a standard pwm pin on a 328 based board?  No mention of current capacity either. This could be useful for use with instrumentation op amp circuits so as to have full 0-5vdc range without having to worry about using rail to rail op amps.

Lefty