I have always wanted to build an electromagnetic generator ever since I was a teenager. That was twenty years ago. Now I have decided to give it a shot.

I have battery positive connected to a charging switch which allows for controlling when the capacitor is re-energised, which is then connected the the coil which produces the magnetic field, which is triggered by the firing switch which is grounded back to the battery negative terminal.

I toggle the charging switch on to charge the capacitor, then I toggle the charge switch off. With the capacitor primed, I trigger the magnetic field by toggling the fire switch.

Something doesn't feel right. I feel as though I am just shorting the battery.

Am I going ok?

 

What are you trying to accomplish? I cannot advise on your unstated goal.

 

I am trying to acomplish generating a magnetic field by electrical means.

 

Where did you get the idea for this electromagnetic generator?

 

Can't remember

 

I am trying to acomplish generating a magnetic field by electrical means.

Then simply connect a power source to a coil. But that is not a generator, it is an electromagnet.

A generator would be made by varying a magnetic field through a coil and would produce an electric current in the coil.

 

I want to use a capacitor to make the field stronger.

 

So, I was looking more into this thing I want to build and I found hundreds of videos on YouTube of teenagers building them. What I actually want to build is an electromagnetic pulse generator.

The videos I watched shows pulling apart disposable cameras and stuff to get at the capacitor. One of them was even building it from a taser. That all looks over complicated, and I think it can be built much more simply.

 

So, I was looking more into this thing I want to build and I found hundreds of videos on YouTube of teenagers building them. What I actually want to build is an electromagnetic pulse generator.

Electromagnetic pulse. Duration 2 ms, current amplitude 100 A, capacitor vo;tage 700 V,
amplitude of magnetic field inside coil is 1.288 tesla.
See this thread.

 

I want to use a capacitor to make the field stronger.

How is a capacitor supposed to make the field stronger?

 

So, I was looking more into this thing I want to build and I found hundreds of videos on YouTube of teenagers building them. What I actually want to build is an electromagnetic pulse generator.

The videos I watched shows pulling apart disposable cameras and stuff to get at the capacitor. One of them was even building it from a taser. That all looks over complicated, and I think it can be built much more simply.

I have no idea what videos you are talking about. Don't be surprised if the majority of them are pure fakes.

Here's something you can do, though.

Make a small coil about the diameter of a dime and perhaps half an inch tall. Wrap lots of turns of magnet wire around it.

Now use a single-pole, double-throw switch to be able to switch a capacitor back and forth between your battery and the coil.

Set a penny or a dime on the coil and charge up the capacitor. Then flip the switch. You'll see the coin jump, though probably not very much. Play with the number of turns and the size of the capacitor and see how high you can get it to jump.

Then get the coil and the coin as cold as you can (dry ice is easy to come by, but liquid nitrogen works much better). Now you should see the coin jump quite a bit more (the difference is impressive if you can get some liquid nitrogen).

I would NOT recommend trying to build the circuit Danko posted -- it's pretty clear that you are just starting out and you have no business messing around with a 700 V source.

 

Haha yeah I noticed the high volts and amperage in that diagran. I have experience with automotive electronics and I noticed those values are dangerous.

Your suggestion sounds something more fun. I was hoping to put a calculator up to it and see if I can crash it.

I dont understand coils yet, but I am going to look into each component in my diagram, but first I need to make sure the circuit in my diagram is correct.

 

When I say correct, I mean is it valid.

 

Your suggestion sounds something more fun. I was hoping to put a calculator up to it and see if I can crash it.

Don't expect to be able to do anything along those lines. When people say that electronics are sensitive to EMP events, remember that everything is relative. Those discussions are talking about EMPs that are so strong that the they are virtually always generated by explosive devices (including nuclear warheads).

Of course, EMP covers a HUGE swath of ground. Lightening is an EMP. Static discharge when you touch something after walking across a carpet is an EMP. Interference from a car's ignition system is the result of a train of EMPs.

Don't get pulled in by Hollywood hype -- they've pretty much never gotten anything right on this one.

I dont understand coils yet, but I am going to look into each component in my diagram, but first I need to make sure the circuit in my diagram is correct.

It's not. You don't want the capacitor in series with the coil.

 

I dont understand coils yet, but I am going to look into each component in my diagram, but first I need to make sure the circuit in my diagram is correct.

At first, try to draw your circuit diagram using rules:

 

I saw a guy in YouTube crash his calculator doing what I want to do.

How come the capacitor shouldn't be in a series with the coil? I thought if the firing switch is off, it would create an open in the circuit and then no current would flow, and then when the firing switch is closed, the capacitor will dump its energy which will then pass through the coil and create an EMP?

 

Danko that looks really complicated and probably not neccessary to learn for such a basic task, but your diagram looks awesome even though I can't understand it.

 

Hmmm you know what, I understand most of it. Why is ground away from battery though when the circuit goes to the negative battery terminal? Or is the triangle the ground symbol?

 

I can't use rules anyway. I'm on a phone.

 

I saw a guy in YouTube crash his calculator doing what I want to do.

What did I say about most of what you will find on YouTube?

How come the capacitor shouldn't be in a series with the coil? I thought if the firing switch is off, it would create an open in the circuit and then no current would flow, and then when the firing switch is closed, the capacitor will dump its energy which will then pass through the coil and create an EMP?

If they are in series, then to get ANY current to flow, BOTH switches will have to be closed (otherwise you have an open circuit).

You will get a pulse of current, but not much. As the capacitor charges, the current will drop quickly. Of course, the magnitude of "not much" depends on the component values used. Once the capacitor is charged, there is no way to discharge it with the switches as you have them. So you will be sitting there with a charged capacitor and no current flowing in your coil no matter what you do.

What you need is basically the following:



With the switch to the left, the capacitor charges to the supply voltage. When the switch is flipped to the right, it dumps its charge into the inductor as fast as it can.

You need to be very careful working with inductors -- if you aren't, you will discover that they can produce huge voltages than can push lethal currents through you in far less than the blink of an eye.