PZT Transformer HV circuit diagram complete

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Spencer DePue
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PZT Transformer HV circuit diagram complete

Post by Spencer DePue » Sat Oct 16, 2010 3:03 pm

My final schematic is for a PZT driven high voltage source is completed. It is powered off of a total of 6 AA batteries. There are two 54 Khz oscillators that drive the SMMTF53P3S45 transformers. The power generated from the PZT's goes to a Voltage multiplier in full-wave operation. I have one question however.. With capacitor 2 in the 555 oscillator circuit rated at 10 nF, will this affect my 54 Khz square wave? I know that in an astable 555 timer circuit, that R1, R2, and C1 are part of the equation, but what about C2? Here is the schematic.
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Chris Trent
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Re: PZT Transformer HV circuit diagram complete

Post by Chris Trent » Sat Oct 16, 2010 4:28 pm

First it looks like you need to do some more research on 555 timer circuits. Plenty of information is available elsewhere on the web so I'm not going to go into it. Besides, that's not really our focus here.

(You might want to look specifically at duty cycle and synchronization, and why are you using two?)

Second you may just want to get some parts together and test it, at least the driver portion. I guarantee you'll learn a lot just playing with it, and 555's are dead cheap and we're big on "Put your money where your mouth is."

You'll need an oscilloscope, but you should be able to scrounge one for less than $100 and you'll use it again I assure you.
You've probably already got a multimeter so no worries there.

Safety tip: Don't try for the multiplier until everything else is working PERFECTLY.
Reality tip: Make sure it suits your purpose. Most fusors use hundreds of watts.

Tyler Christensen
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Re: PZT Transformer HV circuit diagram complete

Post by Tyler Christensen » Sat Oct 16, 2010 4:52 pm

This is getting better than what you previously posted, but it's still pretty far from working properly. For one thing, 555's definitely should not be paralleled in this manner. Even if the frequencies are extremely close, a phase shift will develop between them and they'll just short between each other and your output waveform won't work anymore.

Also, 555's aren't rated for this kind of power output. You need to put a transistor such as a MOSFET between the 555 output and the input of the modules, this will step up the current handling that the 555's lack.

Also your multiplier is not wired properly, it is grounded and powered in the wrong input locations, double check how multipliers are hooked up.

Spencer DePue
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Re: PZT Transformer HV circuit diagram complete

Post by Spencer DePue » Sun Oct 17, 2010 3:06 am

I tested my 555 circuit with a multimeter. It works, but, I am confused whether it produces AC or DC. I used 4 AA in series to power the oscillator, which equates to around 6 volts. However, the multimeter reads 5.8 volts DC and 12.3 volts AC.. I don't know enough about the multimeter to know which one is correct.. It is really important for me to know if this is producing AC or DC. If this circuit produces DC output, how can I make the output AC without altering the 54 Khz signal?

inflector
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Re: PZT Transformer HV circuit diagram complete

Post by inflector » Sun Oct 17, 2010 3:26 am

Spencer,

What do the D and C in DC stand for?

What does the A and C in AC stand for?

How is AC different from DC?

What does the k and Hz in kHz stand for?

How do the A from AC and the Hz from kHz go together?

When you know the answers to these questions, you will know why you need an oscilloscope and why your question is puzzling at best.

Spencer DePue
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Re: PZT Transformer HV circuit diagram complete

Post by Spencer DePue » Sun Oct 17, 2010 3:39 am

AC= Alternating Current ( wave fluctuates between +/- on a graph)
DC= Direct Current (wave stays in one section of a graph)
Khz= Kilohertz (hertz is cycles in a wave per second)
Kilo= 1 thousand

Way to be both condescending and counter-productive Curtis...

[Admin warning: There is a low tolerance for flaming on this board, especially for new members. Keep it civil. -Carl]

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Rich Feldman
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Re: PZT Transformer HV circuit diagram complete

Post by Rich Feldman » Sun Oct 17, 2010 8:21 am

Spencer DePue wrote:
> I tested my 555 circuit with a multimeter. It works, but, I am confused whether it produces AC or DC. I used 4 AA in series to power the oscillator, which equates to around 6 volts. However, the multimeter reads 5.8 volts DC and 12.3 volts AC.. I don't know enough about the multimeter to know which one is correct. ...

Spencer, you must learn enough about multimeters to understand those readings, which may appear to be contradictory . A good place to start is the user's manual. Behavior of AC ranges can be very different for different kinds of multimeter.
I suspect you used an analog meter. Try probing the battery pack with DC and AC ranges, then reverse the probes -- are the results much different than when you probed the 555 output?.
For the 555, try increasing C1 by 100x and probe output with headphones, or increase C1 by 10000x and probe with headphones or LED.

There are many forums well suited to questions and answers at this level -- basic high-school electronics, debugging a newbie's first 555, etc. At least one has been recommended to you.
I mean no disrespect in pointing out that www.fusor.net is not one of them.
Hot rod forums prefer that readers lurk until they know which direction to turn a wrench.
I bet you're smart and eager to learn. You'll feel empowered when you understand how analog and digital meter DC and AC ranges respond to mixed waveforms, and when you have mastered the 555. Enjoy the road!
All models are wrong; some models are useful. -- George Box

Chris Trent
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Re: PZT Transformer HV circuit diagram complete

Post by Chris Trent » Sun Oct 17, 2010 3:32 pm

Curtis was attempting lead you to an answer that you probably already know; that if it has a frequency then it is by definition alternating in some form.

Your circuit also has a DC Bias one way or the other depending on what you are measuring it against so depending on your setup they could both be right.

Unfortunately a typical hobby multimeter is simply not up to the task of measuring accurately at any respectable frequency. Mine flakes out about 2KHz.

The tool of choice for measuring the frequency is an oscilloscope. It will also let you know that you have a nice clean waveform, and you can determine things like duty cycle etc. It is invaluable in power supply design.


I ran across this one the other day that might suit your purpose well:
http://www.seeedstudio.com/depot/dso-na ... p-681.html

I'm looking at modifying the code to make a bin counter out of it, but it looks like a decent entry level scope for the price.

inflector
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Re: PZT Transformer HV circuit diagram complete

Post by inflector » Sun Oct 17, 2010 3:41 pm

Spencer,

I wasn't trying to be condescending. You are asking, as Rich pointed out, high-school learning-level questions. I responded at that level because that was appropriate for someone learning. Just giving you the answers won't help you learn. That's the same way people respond on physics forums to college students who ask questions.

As Rich pointed out, this is not the place to learn that level of electronics. This board expects a high level of self study. Others have hinted that you need to get out the books and this is the reason.

I was hoping you'd lookup the words on Wikipedia and then have a "Do'h" moment. I wasn't trying to be condescending.

You may not be in high-school, so that may seem condescending but I didn't intend it as such so I apologize for offending you. I'm 46 and there are plenty of high-school students (like Tyler [Edit: last year, he's at MIT now]) here that can run circles around my electronics knowledge despite the fact that I took E.E. at a very good school for two years.

But the question you asked displayed a very basic misunderstanding of the difference between AC and DC and how they might be measured. That's why an oscilloscope is a good idea, you can see the difference visually.

- Curtis

Dan Tibbets
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Re: PZT Transformer HV circuit diagram complete

Post by Dan Tibbets » Sun Oct 17, 2010 8:44 pm

Without resorting to preaching, I will attempt to answer you question concerning your multimeter confusion.-
A multimeter generally has settings to measure DC and AC voltage. The DC setting assumes a nearly constant voltage over some reasonable time frame. An AC or pulsating DC signal will confuse it and give some innacurate reading, probably well below the real voltage. The AC setting will average the AC voltage to give you a voltage reading that is generally the voltage RMS, which is generally the value used when you talk about AC voltage . The RMS (root mean square) voltage is generally ~ 66% of the pulsating peak voltage.
A general rule that I think is probably true, is that if you get a higher voltage on the AC setting than on the DC setting, the source is probably AC, or at least pulsating DC voltage.
To really know what is going on you indeed need an oscilloscope.

Dan Tibbets

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