Mark, ,I presume you are using a triac and a controller or comparator cct to trigger at a specific phase angle? I tried this technique using a controller about 15 years ago but chickened out and just use a NTC that I bypass with 16A/250VAC rated relay. If I bypass the soft start, I can trip the mains regularly (1200VA core) - but absolutely never when the soft start is used.
I never measured the inrush current directly, but I've simmed it and the currents are quite staggering - inrush plus cap bank charging = 100's of amps for a few cycles.
I never measured the inrush current directly, but I've simmed it and the currents are quite staggering - inrush plus cap bank charging = 100's of amps for a few cycles.
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Looking at the news today, I was reminded of our successes and failures in the last 50 years. While many here were not doing too much, 50 years ago, I was having the time of my life, (and nursing a potential ulcer), in 1968. But I was not alone. Doug Engelbart was developing the future computer interface at the same time. I remember Doug giving a talk at the engineering class that I was taking in 1966 or so, describing the 'MOUSE' that was a new idea. Apparently, in 1968, he had demonstrated what we normally use today with our computer interactions.
Back in the old days, maybe 50-60years ago, computers were huge, relatively slow, expensive machines that were extremely finicky in their operation. They hired bright young people, like me, to run them, promising more professional jobs in future. They were just huge adding machines, it seemed at the time. Everything was entered by keyboard or punch cards. No video output at all. Printers could sometimes make a picture or a circuit diagram, but it was rare. Often, we actually had to personally transcribe a series of outputs over time onto graph paper to get a graph that we could easily read. Engelbart predicted an almost impossible future, that actually came into being. He was forward thinking and his predictions were successful.
On the other hand, the movie 2001 was WAY AHEAD OF ITS TIME. We still have not caught up to its predictions, and probably we never will, at least in the near future, mostly because our will has been turned from space exploration to wars and money accumulation (by the powerful few). What a disappointment.
My design inventions, that first started in 1968, went on to be industry standards, although they seemed 'extreme' at the time. That is called progress.
Back in the old days, maybe 50-60years ago, computers were huge, relatively slow, expensive machines that were extremely finicky in their operation. They hired bright young people, like me, to run them, promising more professional jobs in future. They were just huge adding machines, it seemed at the time. Everything was entered by keyboard or punch cards. No video output at all. Printers could sometimes make a picture or a circuit diagram, but it was rare. Often, we actually had to personally transcribe a series of outputs over time onto graph paper to get a graph that we could easily read. Engelbart predicted an almost impossible future, that actually came into being. He was forward thinking and his predictions were successful.
On the other hand, the movie 2001 was WAY AHEAD OF ITS TIME. We still have not caught up to its predictions, and probably we never will, at least in the near future, mostly because our will has been turned from space exploration to wars and money accumulation (by the powerful few). What a disappointment.
My design inventions, that first started in 1968, went on to be industry standards, although they seemed 'extreme' at the time. That is called progress.
Well said, John. You have pin pointed the problem. And our generation was going to be different, remember?
Cheers from snowy NC,
Howie
Howie,
Having been in the south when it snows, it is amazingly nasty. Not just the lack of road clearing equipment, but the folks who don't know how to drive in the snow. Hope you are home and toasty.
Of course some folks on Sunday have to watch their sermons, eternally warm and toasty may start to sound like a good idea!
Having been in the south when it snows, it is amazingly nasty. Not just the lack of road clearing equipment, but the folks who don't know how to drive in the snow. Hope you are home and toasty.
Of course some folks on Sunday have to watch their sermons, eternally warm and toasty may start to sound like a good idea!
Howie,
Having been in the south when it snows, it is amazingly nasty. Not just the lack of road clearing equipment, but the folks who don't know how to drive in the snow. Hope you are home and toasty.
Of course some folks on Sunday have to watch their sermons, eternally warm and toasty may start to sound like a good idea!
I drove from Atlanta to Greenville during a snow/sleet/ice storm once. I must have seen 7 Mustangs that were either stuck or slid off the road.
I grew up in W.MA and learned how to drive with a manual transmission doing skid recovery in icy parking lots, which is important as well as really fun...I taught my daughter the same way. You are right though, many Southern drivers regularly underestimate stopping distance during winter weather events and interfere with someone else proceeding through an intersection (the phrase T-bone comes to mind...), or lose traction in corners and end up in a ditch.
We are many miles out in the country where power can take days to be restored, so I have a 4WD truck, generator with fuel for a week, lots of wood for the stove, plenty of comestibles and a great sounding (I think, YMMV) stereo for entertainment. I was nice and warm cooking a chicken, chipotle and tortilla casserole while listening to Magma - Theusz Hamtaahk (YouTube) on generator this afternoon, so hardly roughing it. Thanks for your thoughts.
Cheers,
Howie
Impress a current on coil 1 and measure the voltage difference between coils. That voltage should closely track the current even at high freq., and it should be distortion free... even with the driver overdriven big time (hopefully it's a good design that doesn't bottom out).
If you don't have a current drive amp, use voltage drive and monitor current with a small shunt, and again measure the diff voltage of the coils. Then divide the transfer functions to see how close they relate, and also look at the distortion profiles, they should be identical. You'll probably need an audio measurement suite for this which can do log-sweeps and transfer function math,smth like REW/HolmImpulse/Acourate etc. Don't know if that Liberty SW is capable of handling and manipulating the *full* log-sweep data (that is, *with* distortion components) without majot effort.
Direct control loop on the coil 2 voltage has been tried by many people and they all ran into the problem of coupling at high freq. Some have build a compensator that cancels most of the coupling and could achieve about an octave more upper bandwidth limit.
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Connect it exactly as per the schematic. Connect the coils at the "top". Drive the primary coil, and look at the difference between coils.
The plot should show the losses.
Jn
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This is my idea in general. Bog simple.
See JC!! I can design fancy audio circuits...
Are you suggesting a compensation like this?
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I had to look up a gyrator. The last time I used microcap was about 22 years ago, I do not recall if it had one at the time, I know I never used it.
The non reciprocal nature is interesting, it does seem to accurately portray energy dissipated.
So, it does look consistent with what I am thinking.
So, yah...
jn
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