# Voltage Multiplier in Disposable Camera

Discussion in 'General Electronics Chat' started by don'tknow, Mar 22, 2015.

1. ### don'tknow Thread Starter Member

Feb 5, 2015
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Hi, sorry for bothering , just one question if you can help me understand it little bit more. I have one circuit board from a disposable camera , that increases the voltage needed for the flash . now , I lknow it can increase 1.5 V up to 250 V. And I wonder if it can do the same if I put in , 0,50 or 0,30 V instead 1.5 . thank you

2. ### Papabravo Expert

Feb 24, 2006
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Assuming that no components experience voltages or currents in excess of their maximum ratings -- yes. If you change the input, you'll change the output.

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3. ### WBahn Moderator

Mar 31, 2012
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4. ### WBahn Moderator

Mar 31, 2012
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That depends on the circuit. If it is a straight-up multiplier then, roughly, the ratio between the output voltage and the input voltage will remain about the same as you change the input voltage over some reasonable range. If the circuit is more sophisticated then it will limit itself at the same output regardless of the input you provide, again over some reasonable range. I'm not sure what to expect in a disposable camera since they can assume a particular range of input voltages and are very interested in keeping things simple and cheap. On the other hand, limiting the output isn't too hard and they have a motivation not to have cameras blowing up in people's faces.

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Feb 5, 2015
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6. ### Alec_t AAC Fanatic!

Sep 17, 2013
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You may have a problem using a supply voltage less than 0.6V, since that is below the point at which a silicon transistor will conduct significantly.

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7. ### don'tknow Thread Starter Member

Feb 5, 2015
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Now i have this capacitor full , about 300 V . can i use the kick of that voltage to create a magnetic field in a coil . or it will just fry the wire ? i wanna make sure before i blow it all up.

8. ### MrChips Moderator

Oct 2, 2009
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Details, details, details.

It depends on the capacitance of the capacitor, the size and resistance of the wire.

You can calculate the amount of charge Q stored in the capacitor,

given Q = C x V

If C = 300μF
and V = 300V
Q = 300μF x 300V = 90000μC =90mC

Another calculation is the discharge time.
The time constant = R x C
If R = 1Ω
Time constant = 300μs, the time it will take the voltag to drop to 0.37 x 300V = 111V.

Hence in 300μs, the current will drop from 300A to 111A.

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9. ### WBahn Moderator

Mar 31, 2012
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There's also the detail about the inductance of the coil.

Keep in mind that a capacitor charged to 300V can bite very seriously. Depending on the capacitance and how you get tangled with it, it can potentially bite fatally.

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10. ### don'tknow Thread Starter Member

Feb 5, 2015
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what capacitor needs much less current or 'fils faster and it can create that kind of a pulse that can push one magnet away , and what is the minimum of current and volts needed for creating that pulse , and what kind of a coil you think i need for creating that pulse ?

11. ### Alec_t AAC Fanatic!

Sep 17, 2013
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Your questions are analogous to "How long is a piece of string?". You need to provide details.
Less current than what? Faster than what? What magnet? How much force? For how long must the force be exerted? What is the capacitance of your capacitor? .....

12. ### don'tknow Thread Starter Member

Feb 5, 2015
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haha, sorry, but if you look closer you will see that the answer on my question will be the detail you looking for . questions that you want me to ask you would be the answer on my question . I need the answer on questions you asking me. i hope this clears it up. how long must be the string?

Imagine it this way, electricity generated in a wheel while spinning from point A to point B has to be used for creating a high voltage kick of the electrons in the coil of an electromagnet. so that the strength of that magnet can push away an object that it could't push before using that high voltage. must be efficient as possible from less current possible , if i give the details.. i would know the answer on the question i'm asking .

another example , I generate only enough current to light up one Led light . now i need that to create a high voltage kick of electrons in a coil that could attract or repulse a magnet it could't attract or repulse before we gave it a high voltage kick . that's all . no need for details . what would be the most efficient way known , so you get the most efficient movement between two objects?

Last edited by a moderator: Mar 25, 2015
13. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
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As I interpret your analogy you seem to be under some misapprehension Photo-flash units do not, as a rule, employ a flyback topology -- but rather a 'Royer-esk' blocking oscillator...
As regards Cap selection we'll need more info --- Please be advised, however, that the sites's TOS does not permit discussion of 'rail-guns' and their ilk...

Best regards
HP

Last edited: Mar 25, 2015
14. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
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I beg to differ -- you've told us nothing about the mass of the magnet, desired rate of acceleration, parameters of the stator coil, etc... Moreover, sans details, the compliance of this thread with the site's TOS remains in question...

Best regards
HP

15. ### don'tknow Thread Starter Member

Feb 5, 2015
107
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I didn't create the title of this thread , maybe that's why this is confusing, never mind the capacitor i have , never mind the camera the flash etc.. mind the question i'm asking after the title. I just mentioned that i have this camera if this capacitor can be of any use for that . ok, I will try to rephrase the question one more time when i find the way to do so. best regards.

16. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
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Good idea -- Please know I'm keeping an open mind

Best regards
HP

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17. ### don'tknow Thread Starter Member

Feb 5, 2015
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electricity generated is enough to light up one led light . no more. and Now I need to know what to do with it so it Can push or kick away one
N35 / Ni ,

4300 gauss, magnet .

Can the high voltage kick of that much current be used for kicking the electrons trough the coil so that kick of those the electrons in the coil creates a magnetic field which will kick away the mentioned magnet . I'm out of phrases , haha.

now changing the capacitor will change the possibility and the efficiency of that , my question is what kind of a capacitor can do that the most efficient way? the most efficient way would be the most fastest charging . keeping in mind that i have the most lowest current flow and voltage.

Last edited by a moderator: Mar 25, 2015
18. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
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As I understand your questions you wish to accelerate a 0.43T (4300G) permanent magnet via dumping charge into a solenoid surrounding said magnet?

1) What are the parameters of your power source --That it is sufficient to operate an LED doesn't tell me much...
2)What are the impedance parameters of the solenoid (Spec. DC resistance and inductance)

Best regards
HP

Last edited: Mar 25, 2015
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19. ### don'tknow Thread Starter Member

Feb 5, 2015
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All i need is to know is if it's possible what do I need to make it possible ? sadly i don't have any hard answers on that since i'm trying to get the answer on that . i'm a bad english speaker what makes it even harder to ask the right way.

give me any voltage you can imagine lighting a led, 1,50 V. 1V ? now imagine the lowest current flow you can but it can light a led .( what's that i don't know.) now take that and you wanna pressure it so it can give you a kick of a magnetic field in a coil that can move away that magnet. , imagine the coil you need for that to work. etc. I don't have the answers because that would be the answer i'm looking for.

And now of course when you get all that, now how to make it even more efficient, that means what capacitor to use to make it charge faster to higher voltage but without changing the generated power coming in the capacitor . keep in mind that the generated power is always the same, and you wanna make the capacitor charging the fastest way it can to the highest voltage it can in a way that it can still be able to create a magnetic pulse which will kick that magnet away.

so the all together would be, what kind of a capacitor I need that uses the lowest current possible and charges the fastest way possible to the highest voltage possible , and what kind of a coil i need that can survive that voltage output and create that powerful magnetic pulse which will give me that kick for pushing that magnet away? i hope this helps,

Last edited by a moderator: Mar 25, 2015
20. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
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Without the requested data I can offer only general answers so here it goes...

1)You'll almost certainly need to charge a capacitor to a higher voltage (via, perhaps, a photo-flash inverter)

2)Re: the capacitor -- Note that you need high discharge current and low leakage hence the lowest practical ESR characteristic --- Also the capacitor must be designed to withstand rapid discharge (note: a photo-flash Cap may meet these requirements despite the higher than optimal ESR characteristics of electrolytics)

Best regards
HP

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