Need help designing a high voltage oscillator

First I'll say my electronic skills are quite poor. I'm trying to pulse 5 electromagnets in series between the 1-20 hz range. Apparently the 555 timer only works up to 18 volts. I'd like help designing a tunable high voltage circuit with a tunable frequency and led. First off, what information do I need to start designing the circuit, I'm not sure how much power I am going to need, I just want the EMs as powerful as feasibly possible. I'd like to just hook a dozen or so 9 volts together as the power source. Where do I begin? By the way, I'm not looking for a specific wattage or anything, it's just an experiment.

In the same store where you buy the 555 you can also buy FET`s as a switch controlled by the 555.

As a experiment you do need to know the voltage current rating from your e-magnets, as a example 120V 0,5A magnet x 5 =120V / 2,5Amp your battery is 12 x 9V = 108V / 0,4A.
As a result the battery can not give the power.
In a different setup you can burn the coil.
so they need to be in the same range.

Any DC voltage above 24V gives good burn wounds and above 80V can kill a person.
Be safe and double check always.

When working with high voltages, always keep one hand in your pocket -- that way, you're less likely to form a current path through your heart.

And best bet, as Peter said, is to use a MOSFET (see diagram below). Vcc needs to be high enough to drive the MOSFET. If it's a logic level FET, then 5 volts is enough, otherwise around 10 to 12 volts. Make sure the max Vds is around 1.5 times (or more) the highest voltage applied to the coil.

If the voltage on the electromags is 300V or above, then consider using IGBTs:

http://www.irf.com/product-info/igbt/

And if that high, then REALLY KNOW WHAT YOU ARE DOING, BECAUSE SUCH VOLTAGES CAN KILL THE HELL OUT OF YOU!

Also, consider using something like a 74?138 driven by a 3-bit counter.

*Edit:* That is if you want to sequence the EMs (not sure why I thought that was what you meant, 'cuz I went back and read your post and you said "series" not "sequence")

Thanks for the reply.

How would I find the current of my EMs? Divide the voltage by the EMs total resistance?

What does FET stand for?

I'm thinking since 9 volts are expensive that maybe I should take the 120v AC from the wall and rectify it (bad idea?... most likely).

How do I design the circuit. I think what I'm looking for is similar to this (with an fet, whatever that is). This is a succor punch circuit for resonating a wire around crystals at 15 hz. It just looks like gibbrish to me.

Good tip with the hand in the pocket.

I hate to be the useless noobie, but I just don't know what the hell I'm doing when it comes to designing a circuit. Could you give me an example of what this should look like?

Sorry, but it sounds like you don't have enough experience to be messing with such things. I suggest you enroll in an electronics course or get a book on basic electronics.

I can build circuits, I just can't design them.

Well, what you are asking for takes a lot of time. I'm not willing to design the whole thing (which would involve a lengthy Q&A between us to even get to the point where I know what it is you want designed. And, then, were I to design it, apparently I would have to spell out every detail, such as what a FET is. That's a daunting task!

I suggest you start with basics and get some experience under your belt. Then, perhaps, we can talk.

Also, as you are acquiring that experience, if you should have questions along the way, by all means, ask them on this forum (but be sure to do each one as a new topic, so they're visible to everyone on the forum).

OK, change of heart. I read up on the "Succor Punch" concept and realized that what you need to be thinking about is current, not voltage. The voltage will be high only if it needs to be to drive whatever coil you conceive of--and if you are winding coils that need more than 18 volts, then your getting way into OverKill!

Attached is an add-on to your Zapper circuit. The value of R5 will depend on the current you will be driving with Q1: Ic = hfe * Ib, where Ic is the current into the Collector of the transistor, and Ib is the base current (limited by R5). The hfe (also called beta) of any transistor can be acquired from it's datasheet. For this application, I suggest using the minimum hfe.

If you don't know what any of that means, then read up on Transistor basics:

* http://www.electronics-radio.com/articles/ele...-does-a-transistors-works-basics-tutorial.php
* http://www.electronics-tutorials.ws/transistor/tran_2.html
* http://www.americanmicrosemi.com/tutorials/bipolartransistor.htm

Thanks for the reply. I'm not building a succor punch I'm just using the same pulsing circuit, so I'm not looking for current. I just need to pulse some electromagnets with a high voltage.

I think what I want is something like this. Would this work? (the D of the mosfet will go to the electromagnets, I forgot to draw it in)

More like this (see diagram below). Your diagram isn't complete (no connection to the Source or Drain and not sure what the line is suppose to represent (the one that seems to go from the Drain to the "90V" label)).

In my diagram, R1 can be anything from 0 ohms (i.e. a piece of wire) to infinite resistance. And L1 is the inductor (or inductors in series). Also, you might need to

But, once again, I warn you to BE _VERY_ CAREFUL WITH VOLTAGES THAT HIGH!!! If you injure or kill yourself, I take no responsibility. And, in fact, I highly encourage you to not play with such things until you have more experience!!!

*YOU HAVE BEEN WARNED!!!*

And let me reiterate--if it's inductors you are driving, then it's all about the current.

And make sure the max Vdss on the FET is at least 1.5 times the maximum voltage involved. If 90, then I would go with 135V or above (and I like to take it to 2 times and above).

Also, depending on your application, you will probably want to put a rectifier across the inductor(s) with the polarity opposite to the polarity applied to the coil(s) (i.e. so the rectifier doesn't conduct while the inductor(s) are grounded by the FET (but, instead, conduct when the FET opens in order to dampen any reverse EMF generated by the abrupt interruption of current.

Here's the diagram with the protection diode:

Thanks again! You're awesome.

I'll do my best no to kill myself.

The resistor is merely to limit the current through the inductor. In most cases that "resistor" would be zero ohms, in other words, no resistor. But, since I don't have a clear idea of what you are making, I included the resistor to cover all (or as many as I could think of bases.