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High Voltage Power Pulse Circuit

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Burnt

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I want to start a project to pulse coils of different types & study the effects of the magnetic waves produced. I am a novice at electronics & need some help with things. Please excuse my ignorance with this but i want to give it a go.

I have found a Circuit on the Net --SEE ATTACHMENT & DESCRIPTION BELOW---that will handle high Voltage & Amps & i want to adapt this to my needs.

I can't read the parts listed on the Schematic on my computer as they look all jumbled up & hard to read, could somebody with suitable knowledge help out with this & clarify the schematic & a parts listing & numbers, values etc to suit.

As i understand it Amps are the key to producing powerful coils rather than Voltage--Please advise if this is not so or both can create the same results independantly.

If this is the case i would like to power this circuit from a 12v DC 30-50Amp power source & would like some advice as to what components i should use on this circuit.

If not i can run the circuit from a 240v DC 20 to 30Amp power source & advise again on components would be very helpful.

From what i can see & read the circuit needs a controlled input pulse of 0-5V dc & two 12V dc inputs as well as the main voltage souce marked HV, is this correct?

I would like to have a "variable" pulse generator or circuit as the controlled input pulse if one exists, please advise once again.

Thank You

Circuit Desciption Below:

Fast rise-time high-voltage pulses have many uses ranging from EMC testing to device characterization. The simple, low-cost circuit described here deals with the latter. It’s able to generate 0- to 1000-V pulses with currents up to 50 A, and a rise time of 100 ns for 800 V/30 A. The output can withstand short circuits, and capacitive and inductive loads. Pulse length and repetition rate are determined by an optically isolated TTL-input signal. Commercial equipment like pulse/function generators or a PC can be connected to this input. The pulse’s amplitude is set by the HV supply; a low-cost photomultiplier-type supply (0, 5 ..5 mA) can be used when repetition rates are below 20 Hz.


The circuit operates as follows: when applying the HV supply, C1 is charged up to a voltage HV via R1 and D1 (see the figure). A 0-V control signal keeps the PowerFET Q1 in the off state. A 5-V signal on the control input operates the driver IC2, from which a 12-V signal is presented on the gate of the PowerFET Q1, bringing it into conductance. The output of the circuit becomes −HV volts as the negative terminal of C1 is now grounded. The pulse ends by making the control signal 0 V. Useful pulse length is limited by he voltage drop during the pulse (caused by discharging C1) and by the 100-µs/64-A save limit of the PowerFET. For the values shown, the circuit voltage drop is 10 V for a 1-µs, 10-A pulse.


The short-circuit and overload protection is based on R1. When the output current is rising, the effective gate-source voltage of the Power-FET diminishes, enlarging the FET resistance. With the given 0.1-Ω value, the output current is limited to 50 A. In a short-circuit situation, capacitor C1 can be fully (and safely) discharged in the PowerFET. Reverse voltages caused by inductive loads are eliminated by D1. When the circuit isn’t operating, R14 discharges C1 for safety reasons.


Circuit layout is very important—a groundplane is needed to keep inductance low. C1 must be a low-inductance pulse capacitor. Even the FET driver IC2 needs a low-inductance layout and decoupling. During the leading-edge gate currents, up to 2 A are needed to charge the FET input capacitance. Resistors R1 and R2 have to be made of at least 10 paralleled discretes to get a low series inductance. R4 and C3 compensate for the remaining inductance in R2 (the value of C3 can be changed for this). C2, R5, R6, and R7 form a snubber network to protect the FET against voltage spikes. The values for the voltage and current monitor levels are given for a 50-Ω load.


Higher currents can be obtained by duplicating the IC2-Q1-R1 stage and connecting them in parallel. R1 helps to equalize the current for each stage. A 100-A pulser has been successfully built in this manner.
 

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For a 12V 50A source, use a large sealled lead acid battery.

Alternatively you might be able to buy a power supply that will plug into the mains that will pump out 12V@50A but it will be expensive.

240V@ 30A is 36kW and it far too much for a normal mains socket so that rules out the mains unless you have access to a three phase power network and a mains powered converter is likely to be extremely expensive.

For a 240VDC 30A source, connect 20 sealled lead acid batteries in series.

Always use a fuse when working with lead acid batteries and be careful when working with 240VDC power.
 
Well, if you save the image to your PC and use an image editor, even the one supplied with MS you can blow up the image enough to see the components.

But more importantly is you need to understand what you're dealing with. When working with high voltages, high frequency especially you need to make darn sure it's shielded so you're not exposed to any of it. RF burns are nasty and deadly.

But also curious how you're going to test the "effects of the magnetic waves produced"? I assume you're looking for some particular effect/s?
 
Yes i understand the consequenses involved with high frequency & voltages etc & every precaution will be taken, shielding etc in a controlled inviroment.

You are correct i am looking for a specific effect for a prototype design, not long back i found something by accident with unexpected results & now want to follow this up with a more serious piece of equipment.

As to how to read & record the magnetic waves produced is another issue & i would appreciate any input on this subject.

Maybe an array of Hall effect sensors that are exposed to the magnetic waves produced & then can be recorded onto computer?

On the smaller scale i have been working on i quickly setup a very crude method with an aquarium tank filled with clear baby oil with iron fillings in suspension. Sounds rediculous but it worked extremely well for visual experiments on a small scale & some amazing visuals were experienced.

Any input on this would be greatly appreciated.

Thank You
 
Burnt said:
...i found something by accident with unexpected results & now want to follow this up with a more serious piece of equipment.
You might want to explain this in greater detail. No offense intended, but electromagnetism has been studied for well over a century; its rather unlikely you've stumbled upon something novel.
 
I²R said:
You might want to explain this in greater detail. No offense intended, but electromagnetism has been studied for well over a century; its rather unlikely you've stumbled upon something novel.


No offence taken or intended in the following.

Yes electromagnetism has been studied for over a century with everybody on the same wave length, all the major findings where actually stumbled upon & then studied further.
Not to long ago we thought the world was flat until somebody discovered different, were we to sit back in fear of the unknown never to venture out in case we dropped off the edge as was believed.

Space has also been studied for centuries but so far we have nothing except a big bang "theory" believe it or not. Even now we find things within our own universe that have been undiscovered previously by countless thousands.

Even the old humble internal combustion engine has been around for some time but still we have an inefficient piece of scrap iron or alloy.

Most of this is due to the fact that we learn A B C 1 2 3 from an early age & mankind just rolls along with what others have found & branch out from there instead of breaking new ground.

Often futile attempts are made at rediculous things like space travel with the current lack of technology for instance, has anybody ever sat down to realise just how long it takes to get to the outer reaches of space & how many generations of humans it would take to do it. One thing is for certain with the current fire cracker technology we have no hope of venturing anywhere.

Electromagnetism is probably the most misunderstood thing of all, a hundred years ago we found we could do things with it but how far actually have we come from these humble beginnings. I'm not talking about ancillary items that make our lives more comfortable or interesting but more real smack in the face life changing things.

When you do find something unique you have to test it & follow all leads & hence the need for some advice on reading & collecting data on the magnetic waves for instance.

Once i have this setup & can start to test some things accurately i will gladly share some information. From small test models some of the results are very interesting & may or may not change the way we do a few things.

At this stage it looks promising indeed to generate a huge amount of power from a relatively small source but time & testing will tell.

Any help wth this will be greatly appreciated.
 
You hardly need any current at 12V. A 100ma supply will work as the Max626 will draw around a maximum of 80ma depending on the switching rate. The high voltage side (1000V) needs about 5ma (5 watts) according to the article. This circuit, while it will supply high voltage/current pulses, does not deliver much average power due to the narrow pulses it is capable of producing.
 
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