High Frequency High Voltage Ramp Generator Circuit

[Khashia]

I want to have some expert opinion on the possiblity of generation of High Voltage(10-12KeV) and high Frequency (GHz) ramp? Is it achievable and if so how? I Know that frequency is not a problem(in low voltage range) but if combined with voltage requirement what is the maximum volt and freq that is achievable and how?

 

[FvM]

The term "ramp" suggests that the signal bandwidth must be much higher than the fundamental ramp frequency, which is most likely infeasible at GHz. You should specify the intended waveform.

 

[goldsmith]

I want to have some expert opinion on the possiblity of generation of High Voltage(10-12KeV) and high Frequency (GHz) ramp? Is it achievable and if so how? I Know that frequency is not a problem(in low voltage range) but if combined with voltage requirement what is the maximum volt and freq that is achievable and how?

Hi Khashia

I know many ways for achieving high voltage ramp waves but the required frequency in your case is too high . can you tell us more about what you're about to do with that ? why you need such a wave in such a high frequency and such a high amplitude please ? i think thus we can help you an appropriate way .

Best Wishes
Goldsmith

 

[Khashia]

The signal is required for an analog oscilloscope at GHz freq. Ramp waveforms at GHz freq r feasible with the help of digital/mixed signal generators
but is that achievable at KeVs range(electron beam energy)?

 

[goldsmith]

The signal is required for an analog oscilloscope at GHz freq. Ramp waveforms at GHz freq r feasible with the help of digital/mixed signal generators
but is that achievable at KeVs range(electron beam energy)?

Hi Khashia
For creating a high voltage ramp waveform , and in GHZ range on of the good ways is creating a square wave in GHZ range which is not hard , and then leading that through the LR circuit ( linear LR circuit ) in order to make a ramp wave with HV range . if you need more precision you can use a current source which is based on HV transistors and then a capacitor which the squared wave will be leaded through it . that's all .

A notice : please be careful while you're doing it because you're dealing with high voltages and high voltages are absolutely harmful .

Good luck
Goldsmith

 

[FvM]

The signal is required for an analog oscilloscope at GHz freq. Ramp waveforms at GHz freq r feasible with the help of digital/mixed signal generators
but is that achievable at KeVs range(electron beam energy)?

To avoid misunderstandings, you should tell what you exactly want to achieve.

Horizontal amplifiers of analog oscilloscopes (also high speed types) are working with voltages in a 100V range.

 

[Mr.Cool]

ya, that confused me when you said the application was oscilliscope. that's low voltage.

another way to produce high voltage with extream ramp rates is to charge an inductor and then open circuit it

 

[goldsmith]

another way to produce high voltage with extream ramp rates is to charge an inductor and then open circuit it

Hi Mr cool

And then what ? after opening the circuit we just see every switch which has opened the circuit is just destructed isn't it ? unless we use a freewheeling path ? which will deal with unwanted oscillations too and more problems this way will work as well with some optimizations but i think capacitors are better in this case . isn't it ?

Best Wishes
Goldsmith

 

[Mr.Cool]

i didn't understand your capacitor method so i can not say.

but i have built an incredibly efficient battery charger using the "open an inductor" method. yes a free wheeling diode is used to provide a path to send the voltage spike to the charge battery. so i thought i would mention it as one way to get a high voltage in very short period of time.

my application .. its a two battery system, one 12V battery is used to charge the inductor, transistor open circuits the inductor, 1000V voltage spike goes to other 12V batter via a diode.. it is pretty different method to charge a battery .. it is not a constant current method, it is pulsed voltage. i know putting 1000V spike on a 12V car battery sounds like an explosion ready to happen.. but the timing is so short. like passing your hand through a flame .. if you're fast you do not get burned. nice thing about this method is it simultaneously breaks down any plate build up that occurs during use so it is like you always have a brand new battery .. not one that can only be recharged X number of times. also.. there is no heat build up (which is the true killer of batteries) since we are not using constant current but rather spike of voltage.

 

[goldsmith]

i didn't understand your capacitor method so i can not say.

Hi Mr cool
It is not complicated ! i suppose you are familiar with action of a capacitor as well , isn't it ? so it is a well know nonlinear element . a current source and lead it into a linear element . ok ? so it will behave as a very good integrator or perhaps a self excited ramp generator if we prepare a loop for that . ok ? ( as it has been used since some decades ago ) so it will be more controllable and there won't be any risk factor of unwanted spikes with pretty high amplitudes . that's all .

but i have built an incredibly efficient battery charger using the "open an inductor" method. yes a free wheeling diode is used to provide a path to send the voltage spike to the charge battery. so i thought i would mention it as one way to get a high voltage in very short period of time.

What we're talking about in here ? a charger ? or perhaps a GHZ range HV ramp generator ?


Regards
Goldsmith

 

[Mr.Cool]

i understand now thanks. use a square wave signal generator and run that through RC to get a ramp. your signal generator has to have huge slew rate though.. which is the part that makes this very tough to achieve for high voltage ramp.

what about charging an inductor and then open circuit it like i suggested, use free wheeling diode to lead this voltage spike to a high voltage capacitor like you suggest to control the ramp?

great minds work'n together

 

[goldsmith]

what about charging an inductor and then open circuit it like i suggested, use free wheeling diode to lead this voltage spike to a high voltage capacitor like you suggest to control the ramp?

Hi Mr cool
Yes it is possible but with very bad spikes of course which should be modified . another problem is unwanted transmissions which require proper shielding and be warned of how to make such an inductor because the voltage is too high and spiral inductors or helical inductors on the boards may be destructed by delivered arcs due tot eh breaking the insulator .

great minds work'n together

Certainly ;-)


Best Luck
Goldsmith