How do I increase energy flowing into a Capacitor?

330v AC is more than 400v DC when rectified.

 

Hi Electro
speaking for myself, you probably scare us all.
Do you realise what will happen once that capacitor is fully charged? It'll carry a potentially lethal charge of energy, perhaps for days or weeks.
And you'll probably think I'm kidding here, so check it out: even a 9V battery can kill an incautious user! It happens several times a year, here in Australia alone.

You can have way more fun at much lower voltages, and never come close to hurting anybody. I've been reluctant to add to Harald's excellent advice, but I'll say this - that if you were to be killed playing with these horribly dangerous things, and I'd shown you how to maximise the danger to yourself, I'd feel responsible.

Do you have an electrician or technician friend? Wouldn't it be a good idea to join some kind of club or group which is interested in electronics, and get some experience with a bit of help from someone who already understands the dangers?

 

I like your go get 'em attitude.
I think you need a signal generator, an oscilloscope, a low-voltage, dual tracking power supply, and a few hand tools.
An excellent book is still "The Art of Electronics" by Horowitz and Hill.

You can learn about transistors, triacs, op-amps, logic circuitry, and signals, all at low, safe voltages. Even at those safe voltages, you'll possibly have accidents that cause injury.

A safe environment is one without danger; a nearly safe environment is one in which someone very capable is there with you in case things go wrong.

 

poor mystic,

Can you provide a link to support this?:

Wiki side note: "Killed by 9V Batteries is an Austrian[1] indie rock rock band."

Ken

 

No I can't, I'm sorry. The reason I can't provide a link is that the rumour, that 9V batteries can kill someone this way, turns out to be a myth.

I think I need my embarrassed emoji.

 

Ah! Coil guns. Those are fun to play with, and relatively "safe" if proper precautions are made working around the electrical components. The problem is you can't really accelerate a projectile to "interesting" velocities like, say, hypersonic with just one coil. Discharging a capacitor into a single coil delivers an "impulse" of force to the projectile. That impulse contains all the energy that can be transferred to increase the momentum (velocity) of the projectile. If you want a higher velocity you can either try to increase the magnitude of the impulse (more current) or increase the number of coils the projectile passes through. Each coil gets a discharge as a separate impulse, precisely timed of course to occur as the projectile enters each coil in succession.

With just one coil, and a few thousand microfarads charged to a puny three hundred volts or so, you might as well use rubber bands to store energy and to launch your projectile. Do the physics and then do the math.

As you have no-doubt discovered by now, the circuit used to charge the energy storage capacitor in a disposable flash camera is pretty wimpy, running from a little 1.5 VDC dry cell and with everything squeezed into a little plastic case not much larger than a deck of cards. So... why would you be surprised that a circuit that, going "all out" to charge an 80 μF capacitor to 300 V or so in ten to thirty seconds, would take much longer to charge your 2200 μF capacitor to the same voltage... like more than 27 times longer? You don't need to "improve" the circuit removed from the disposable camera: you need a new circuit, i.e., a new power supply that runs on something other than a single AA dry-cell.

I think, given your level of "expertise," most of us here would be unwilling to recommend or provide you with a schematic for a power supply that would charge your capacitor in a few seconds (or less), whether it be line-operated or battery operated. Of course you can Google any of the many "coil gun" projects documented on the Web and find something that will do the job, and perhaps you could even build it and use it without injury to yourself or others who happened by. But I don't think I want to be involved just yet. Sorry 'bout that. It's no reflection on your aspirations to learn about coil guns. Go learn some more about electricity, circuits, and electronics. Then come back here with more questions, since I am pretty sure no one ever learns all there is to know about anything.

Hop

 

I have been interested in, and sometimes professionally involved with, electromagnetic launchers since I was a teenager. A few years ago, one of the scientists that I had worked with bragged about a rail gun his team had built that he said was capable of launching "one pound to Jupiter!" At the time I sort of brushed his remark off because this individual was a known drama king... he once bragged about a certain precision optical metrology system that, according to him, was so well designed it could be assembled on orange crates, this when we were spending thousands of dollars for air-suspended granite optical tables. But he sure could sell R&D research projects to the government. He once brought an Australian scientist to work in the States because the Aussy was an expert in homopolar generators. I spent a few years working for him trying to build a flash xray motion-capture camera for underground nuclear tests. The goal was one million frames per second and at least nine high-resolution frames. I failed at this task because I couldn't magnetically deflect the image to nine different positions on a cathode ray tube with sufficient speed and stability to achieve both the resolution and the speed required. The project went away, but I later learned that the image capture problem was accomplished with a different technology than the one I was asked to use. There's always more than one way to skin a cat, assuming you can catch and skin it at all.

In case you don't know what a homopolar generator is, it's something Michael Faraday dreamed up in 1831 while "messin' 'round with magnets." Basically, it's a copper disk rotating on an axle with an external magnetic field applied parallel to the axle (perpendicular to the rotational plane of the disk). When the disk is rotated, a DC electrical field is produced radially between the axle and the outer edge of the disk, polarity depending on direction of disk rotation and orientation of the external magnetic field, voltage depending on how fast you spin the disk.

Now take this simple description and hand it to an engineer who will scale it up to industrial strength: two copper disks rotating in opposite directions so their angular momentum cancels, each disk weighing in at about a ton or so and several feet diameter, a monster electromagnet to apply a one or two tesla magnetic field, electrical contacts at the axle and on the two rims capable of handling several million amperes, a prime mover in the form of a rather largeish three-phase induction motor and you now have a rail-gun power supply. You need only add the rail-gun and a suitable switch capable of passing a mega-ampere or so of current.

IIRC this research occurred in the late 1970s and continues to this day. There is a machine shop here in Dayton that builds rail guns for the U.S. Navy, and also machines test projectiles made from aluminum block cubes about eighteen inches on a side. These weigh considerably more than a pound, so the "one pound to Jupiter!" quote was probably referring to another rail gun in an earlier stage of development. AFAIK the homopolar generator was never built for a rail gun application. I personally thought it would have been a great thing to use in an Army tank, spun up with gas turbines. The Navy powers their rail gun from capacitor banks, conventionally charged from ship electrical power and switched with thyristors.