That might be a reference to Jack Gerritsen?
He'd been jamming amateur radio repeaters, Red Cross radio, MARS, California Highway Patrol, and the U.S. Coast Guard Auxiliary (during a search-and-rescue operation).
There are other, similar cases on record:
[...]
Sounds interesting. We have Virgin Mobile phone-only. Minutes never expire and over the years we've racked up over $300 in unused funds that would instantly evaporate if we switch to another carrier. It uses Sprint and that network seems to have a bit better coverage in remote areas than a friend's TracFone. As a mountain biker remote coverage is important to me.
Their cheapest data plan is $35/mo, plus the new commie tax.
-- Regards, Joerg http://www.analogconsultants.com/
No wonder those guys got locked up. Blocking emergency radio traffic or ramming vehicles is serious stuff. Probably all of them need some psychological help.
-- Regards, Joerg http://www.analogconsultants.com/
I wouldn't like to not have my smartphone
For work usage:
Taking pictures of test setups etc Checking SED during boring meetings HP48 emulator calculator Sound spectrum analyzer Flashlight Datasheets WIFI analyzer
Cheers
Klaus
Agreed. Impulse control problems, inability-to-learn-from-their-mistakes problems... they seem to be "loose cannons" in a social sense, and radio jamming is just one of the ways they act out.
That's probably what I'd use it for. But my little Samsung netbook works fine for all this, it's just larger and heavier. Also, phones have screens that are too small. When you get older you know why ...
-- Regards, Joerg http://www.analogconsultants.com/
Not necessary. It has its own battery.
>
Ouuu, sound spectrum analyzer would be nice! Can I "look" at water falls and babbling brooks?
George H.
Way back when someone suggested two steps. (If it's not to late to try something else.) Maybe there's some commercial product to do the first step? George H.
Sure it's possible. It's a PITA and doesn't really save much, if anything but such plans are certainly available.
...or the judge was a ham.
This was in New Orleans, a long time ago. The judge was an old crust who didn't know anything about ham radio, but said that we can't have people going around breaking the law.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Any progress on this?
RL
I'll have to ask Virgin Mobile if they allow it. Unfortunately phones are mostly provider-locked in the US so you are at their merci. As for savings the difference is huge. With the new commie tax it's roughly $8 versus $40 per month. Now I don't mind paying that but not if I really never use the data part of it. I consider it one of the not so great "advancements" of civilization when 10 people sit at a bar, nobody talks and they all incessantly tap on and stare at their "smart" phones. Or you are in a nice conversation, something goes bipp-boink deedle-dee and the other party excuses themselves to stare at that little screen. I don't want to belong to that crowd.
-- Regards, Joerg http://www.analogconsultants.com/
I've got several FFT packages on my netbook. So the other day I sat in a Boeing and turned it on. The weather was iffy and the pilots tried various altitudes while hand-flying. It looked like they had permission to dodge storm cells as they saw fit. You could see the lines proportional to how the turbo-fan engines spooled up and down upon control input. It was impossible to hear over all the din such as rattling but the waterfall display clearly showed those lines. That was cool.
-- Regards, Joerg http://www.analogconsultants.com/
Or change the snubber, so more energy goes straight into the load.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Well, i have been avoiding this mess, but.. There is this talk of a snubber dissipating energy and creating not-too-useful heat. You whine about poor efficiency and ignore the obvious reason.
Take this waterfall of energy and use it!
I'm sure he's open to useful ideas. Small flybacks with non-dedicated magnetics doesn't sound like an application that's likely to welcome added complexity.
If he's really using SIC schottkys for the clamp, he could reduce the energy burnt in the clamp by replacing it with a rectifier that actually has measurable reverse recovery, as this will retransfer leakage energy back into the primary. Where it goes from there is another issue, but ideally it can be used to do something, if the clamp alternative is to burn-only.
Poor coupling is an issue with flybacks, but not with small flybacks, because 'who cares'.
RL
I did that type of troubleshooting, too, until I remembered I had purchased a FLIR prompted by a JL post. I used it and found that I had needlessly removed two ICs because the ceramic filter capacitor was leaky. That FLIR can see very tiny temperature differentials.
I'll never be without one henceforth. Thanks, John L.
How about using this topology with a bridge circuit (
Here is a one [active] switch inverter - but besides the one switch, it also has two parallel coupled reverse-blocking-switches closer to the output, that functions as active rectification - see the schematic at page 2:
A Synchronous Single Switch Inverter - Purdue School of:
Therefore, as the number of high frequency switching devices is decreased, the efficiency is increased. For instance, a 90% efficient [H-bridge] converter becomes 97.2% efficient. ... CONCLUSION A new power inverter circuit was introduced that required only one high frequency switching transistor. The inverter used a synchronizing structure to change the voltage polarity on demand. Therefore, real time generation of infinite voltage levels was realized. The state space equations demonstrated a forth order system. ..."
The inverter could be used for solar micro-inverters:
The inverter could also be used for:
The circuit is a "all-in-one". It could be used for (T1 and T2 refer to the iupui.edu article):
Could it be used for a Class D audio amplifier with the right control circuit? Low enough distortion?
The circuit bear resemblance with a reversed SEPIC:
Indiana University. (2012, October 17). New class of power inverter could mean cheaper, faster hybrid vehicles. ScienceDaily:
Additional reading:
Active rectification (synchronous rectification):
They must be but besides the one switch, it also has two parallel coupled e.g. Reverse Blocking IGBT (RB-IGBT). (Or two serially connected Power MOSFETs. The Power MOSFETs must be connected so that their substrate diodes have opposite directions):
Application Characteristics of an Experimental RB-IGBT (Reverse Blocking IGBT) Module:
A High Efficiency Indirect Matrix Converter Utilizing RB-IGBTs:
Definition:
Better name: One active switch inverter.
The two active rectification switches are passive switches.
.A half bridge uses two active switches.
A full bridge uses four active switches.
-Alternative:
Design:
T1 serially connected to T2.
T1 is N-MOSFET with drain "up" (drain connected to L2 and C1).
T2 is N-MOSFET with drain "down" (drain connected to zero/commen).
T1 and T2 sources connected together.
.Active rectification:
When positive output is needed T2 is on. T1 do active rectification.
When negative output is needed T1 is on. T2 do active rectification.
-For T1 and T2 (passive switching/active rectification):
I have unfortunately not tested it yet.
Glenn
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