Hi If you go the Krytron route you probably will need some fairly fancy transformers as well….
Bob On Dec 26, 2013, at 11:19 AM, Jim Lux <[email protected]> wrote: > On 12/26/13 8:07 AM, ct1dmk wrote: >> Hello, >> >> I'm willing to generate a pulse (of some few hundred volts) >> by discharging a capacitor into a pulse transformer >> I'm solely interested is the active edge (call it either rise or fall >> depending on the >> wiring of the output of the transformer). >> > > ns risetime pulses sounds like fairly straight forward radar stuff. > > the inductance of the transformer is going to be your challenge, depending on > the energy level. What about a non-transformer alternative? Can you just > charge your cap up to the few hundred volts and have a switch that can take > the voltage? > > How much energy do you need? You said a few hundred volts, but is that > microjoules, joules, or kilojoules? > > A small triggered spark gap would be one way. There's also the ever popular > krytron, which has very good timing accuracy. > > YOu might look for circuits used for exploding bridge wires (EBW) > > >> The target is 4ns, while ideas seemed to be clear at some point, now I'm >> having doubts if better to use a MOSFET or a bipolar transistor >> as the switch element. Experiments with MOSFETs presented me some >> difficulties charging the gate capacitance having some trouble to >> achieve something in the 4ns region. Well 4ns seems hard whatever device >> anyway. > > You want some sort of RF transistor here. What about one of the new LDMOS > FETs: some have fairly impressive voltage handling, and if they work at 1 GHz > for radar applications, they will work for you. > > What about stacking a bunch of MMIC RF amplifiers (e.g. like the ERA or GAL > from minicircuits) > > > Other traditional approaches to fast pulse generation are avalanche > transistors. > > > There's also a variety of interesting pulse forming networks that can > generate fast rise time high voltage pulses. Blumlein arrangements are one. > Your 100ns pulse is fairly long for a transmission line scheme, though (20-30 > m of coax) > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
