I see your point Jeff. I did use the oscilloscope to figure out the minimum pulse width attainable by the IOIO board I am using with my Android phone. It will go down to 65 ns.
Arnaud (or anyone who can answer), So if I understand correctly, you could use a PWM pulse with an H bridge to get AC from a PWM signal? I think I looked into this before, and the problem would be that you wouldn't have the "dead space" in the current. Let's say you have a 100 ns + current and when this is switched off, the H bridge allows the - current for the remainder of the duty cycle. This gets you closer, but is still not what is needed. If I understand correctly, you need a bipolar pulse (then no current in between the pulses). On Thu, Nov 22, 2012 at 4:45 PM, Jeff Berkowitz <[email protected]> wrote: > You don't need a high speed scope if the circuit is working *correctly*. > But if it's working correctly, you don't need to measure it at all. ;-) > The reason for a high speed scope is to observe the behavior when it's not > working correctly. It's a high-power, high-speed AC circuit, so errors or > bad construction practices may produces really weird results that simply > won't be observable with a low-bandwidth instrument. > > I wouldn't read too much into the divisions on the scope. The probe and > scope electronics will act as a low-pass filter, so you'll a smoothed and > rounded representation of reality. It's not the frequency of the pulses > that's the issue here, it's the harmonics that compose the rising and > falling edges of the pulse. > > For AC pulses you can look at Arnaud's message. Godes didn't use this > approach, I think - instead the clever use of T8 as both an inductor and as > the primary of an isolation transformer; then by suitably referencing the > secondary side, the core sees AC. I could be misreading the design, > however. There are four MOSFETs in Godes design. > > Jeff > > On Thu, Nov 22, 2012 at 1:59 PM, Jack Cole <[email protected]> wrote: > >> Jeff, >> >> I don't think your scope would need that level of resolution. Godes >> describes using the following: A 100MHz Fluke 196C oscilloscope meter. >> >> Anyway, there is not a lot of info on the net about using PWM to make >> bipolar pulses. Producing a DC pulse to those specs is not so difficult. >> A bipolar pulse seems to be a different story. >> >> I have a 25mhz oscilloscope, so I'll try to see if it has the resolution >> needed. Supposedly, it will show down to 5 ns/div on the horizontal axis. >> I'll try to experiment to see if I can get a 100 ns DC pulse with PWM and >> see how the scope does. >> >> Here is the scope I have. >> http://www.amazon.com/dp/B007T6XNCA/ref=pe_175190_21431760_M3T1_SC_dp_1 >> >> Jack >> >> >> On Thu, Nov 22, 2012 at 3:38 PM, Jeff Berkowitz <[email protected]> wrote: >> >>> Interesting. A U.S. nickel is 1.95mm thick. >>> >>> >>> On Thu, Nov 22, 2012 at 1:21 PM, James Bowery <[email protected]>wrote: >>> >>>> It's hard to know where to begin here but let me just say this that >>>> given the speed of sound in >>>> nickel<http://www.olympus-ims.com/en/ndt-tutorials/thickness-gage/appendices-velocities/> >>>> : >>>> >>>> 5630m/s >>>> >>>> and 430kHz: >>>> >>>> 5630m/s;430kHz?mm >>>> >>>> ([5630 * meter] / second) * (430 * [kilo*hertz])^-1 ? milli*meter >>>> = 2.0838194 mm >>>> >>>> In other words, a 2mm electrode should exhibit resonance at ~430kHz. >>>> >>>> >>>> On Thu, Nov 22, 2012 at 2:47 PM, Jones Beene <[email protected]>wrote: >>>> >>>>> On the contrary James, at least two of us did look closely at this >>>>> possibility [electrode acoustics]. **** >>>>> >>>>> ** ** >>>>> >>>>> My associate went to trouble to find and download a mpeg sound file of >>>>> a bicycle bell of the same general size as Davey’s, and plugged it into a >>>>> program for this kind of analysis – in fact it is dedicated bell analysis >>>>> software that has proved very accurate for electrodes in the past. The >>>>> natural acoustic of this hemisphere are nowhere close.**** >>>>> >>>>> ** ** >>>>> >>>>> The main freq is 4,445.5 Hz, with some sub harmonics, the lowest being >>>>> around 521/545 Hz, but those are so faint as to be discarded. Higher >>>>> harmonics are barely above noise.**** >>>>> >>>>> ** ** >>>>> >>>>> Thus, since the acoustics of the electrodes were off by two orders of >>>>> magnitude over the signature sound, we did not think that electrode >>>>> acoustics were in any way relevant as an alternative explanation, or >>>>> otherwise worth pursuing.**** >>>>> >>>>> ** ** >>>>> >>>>> Jones**** >>>>> >>>>> ** ** >>>>> >>>>> ** ** >>>>> >>>>> *From:* James Bowery **** >>>>> >>>>> ** ** >>>>> >>>>> As I previously >>>>> advised<http://www.mail-archive.com/[email protected]/msg73144.html> >>>>> :**** >>>>> >>>>> ** ** >>>>> >>>>> "Look at the acoustics of the electrodes."**** >>>>> >>>>> ** ** >>>>> >>>>> Since this advice seemed to make no impact on the discourse here at >>>>> vortex-l, let me expand:**** >>>>> >>>>> ** ** >>>>> >>>>> Acoustic resonance in the metallic electrodes does have a reasonable >>>>> chance of bearing directly on the creation of the "nuclear active >>>>> environment" hypothesized to exist. I don't think I need to expland on >>>>> list the possibilities here.**** >>>>> >>>>> ** ** >>>>> >>>>> Moreover, if one looks at the speed of sound in metals, the "430kHz >>>>> LENR signature" regime corresponds to the thickness of the cathodes >>>>> frequently reported as exhibiting the phenomena.**** >>>>> >>>>> ** ** >>>>> >>>>> Need I say more?** >>>>> >>>>> ** ** >>>>> >>>> >>>> >>> >> >
