On Mon, 24 Oct 2022 13:16:20 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:
>We have some sims that run absurdly slow. What are your favorite
>speedups?
>
>In LT spice, I have arbitrarily done
>
>.opt reltol=.002
>
>.opt abstol=5n
>
>.opt trtol=5
>
>but that's just guessing. It may work with my parts but mess up an
>encrypted model that I have no visibility into.
>
>Sometimes one solver is unaccountably better than another.
On Fri, 28 Oct 2022 04:38:54 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:
>On Fri, 28 Oct 2022 04:56:20 GMT, Jan Panteltje
><pNaonStpealmtje@yahoo.com> wrote:
>
>>On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>><99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
>>
>>>I am struggling for every square mm of board area.
>>>
>>>>OTOH BAD things must happen for those parts not to be around anymore
>>>
>>>Parts seem to be available more lately, especially direct from TI.
>>>
>>>
>>>
>>>>
>>>>That was to keep my drone airborne via a thin coax carrying high voltage
>>>>transformed back to 7V at the drone:
>>>> http://panteltje.com/pub/drone_power_small_core_test_IMG_6114.JPG
>>>> http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
>>>> http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
>>>
>>>I tested a 30 ga twisted pair of magnet wire. It failed at 1400 volts.
>>>Wire-wrap wire must be 10 KV-ish. You'd need a clever HV downconverter
>>>to use really light wire.
>>>
>>>How about a single wire to power a drone?
>>
>>How would that work?
>
>High frequency AC, working against the capacitance of the drone to the
>world. Some tuned circuit on each end.
>
There is a standard dodge, a wire with a thick dielectric jacket (like
coax without the shield), carrying a GHz RF signal in guided-wave
transport mode. The ends are a pair of horn antennas that launch and
receive the RF energy.
This has been used for data links in fielded military systems, but
probably not at the power level needed to fly a drone.
Joe Gwinn
Reply by Jan Panteltje●October 28, 20222022-10-28
On a sunny day (Fri, 28 Oct 2022 08:32:43 -0700) it happened John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote in
<m6tnlhdnfeofpbujravmshh037au26edhi@4ax.com>:
>On Fri, 28 Oct 2022 12:09:36 GMT, Jan Panteltje
><pNaonStpealmtje@yahoo.com> wrote:
>
>>On a sunny day (Fri, 28 Oct 2022 04:38:54 -0700) it happened John Larkin
>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>><gifnlh12i7v6oscm5jqguafukd9abl6i8s@4ax.com>:
>>
>>>On Fri, 28 Oct 2022 04:56:20 GMT, Jan Panteltje
>>><pNaonStpealmtje@yahoo.com> wrote:
>>>
>>>>On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
>>>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>>>><99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
>>>>
>>>>>I am struggling for every square mm of board area.
>>>>>
>>>>>>OTOH BAD things must happen for those parts not to be around anymore
>>>>>
>>>>>Parts seem to be available more lately, especially direct from TI.
>>>>>
>>>>>
>>>>>
>>>>>>
>>>>>>That was to keep my drone airborne via a thin coax carrying high voltage
>>>>>>transformed back to 7V at the drone:
>>>>>> http://panteltje.com/pub/drone_power_small_core_test_IMG_6114.JPG
>>>>>> http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
>>>>>> http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
>>>>>
>>>>>I tested a 30 ga twisted pair of magnet wire. It failed at 1400 volts.
>>>>>Wire-wrap wire must be 10 KV-ish. You'd need a clever HV downconverter
>>>>>to use really light wire.
>>>>>
>>>>>How about a single wire to power a drone?
>>>>
>>>>How would that work?
>>>
>>>High frequency AC, working against the capacitance of the drone to the
>>>world. Some tuned circuit on each end.
>>>
>>>>Maybe optical fiber for a high power laser? Never tried that, do have some optical fiber here..
>>>
>>>Power over fiber is done, but it's expensive.
>>>
>>>>These coaxes I use have teflon based insulation and are really good for some hundreds of volts,
>>>>very light at that,
>>>>The idea was to make as little RF as possible (am using about 100 kHz), put a small antenna on the drone
>>>>and send the amplified received RF down the same coax (many MHz), or even use the whole coax
>>>>as shortwave antenna, balloon would work too of course,
>>>>just playing and investigating :-)
>>>>
>>>>
>>>>
>>>
>>>Tried Micro-coax? Really tiny stuff.
>>
>>Did not know about that, did some web searching now
>>but on the Mouser link I see max 30V rms
>> https://eu.mouser.com/new/alpha-wire/alphawire-micro-coaxial-cables/
>>
>
>That's silly. Nothing breaks down at 30 volts. I expect it's good for
>a few KV at least. When I was a kid I ran RG59 at 12KV. That's another
>story.
TV HV?
>>was just a test, cannot even fly a drone where I live now
>>area is close to mil airport, helies and F35 and F16 all the time
>>Now soon with nukes, one coming right now ;-) (sound).
>> (US wants to ugrade the nukes it has stationed in Europe including here I suppose)
>>
>>Such a small drone wants about 70 W for flying:
>> http://panteltje.com/pub/hubsan_h501s_current_test_full_throttle_IMG_6290.JPG
>> more than 10 A DC at 7 V or so.
>>
>>So using high voltage AC to get the current in the coax down, and transforming and rectifying
>>back at the drone side:
>> http://panteltje.com/pub/h501s_drone_remote_power_drone_side_IMG_6278.JPG
>> The propeller air stream cools the rectifier diodes and the ringcore.
>>It all works :-)
>> Those are special diodes and special high quality elcos,
>
>
>Send DC up to avoid rectifying and filtering. There is probably some
>cute little switcher chip to go from, say, 150 DC down to 7.
Good idea, but it is 10 A, needs big inductor anyways.
If you go higher in frequency maybe a smaller inductor but harmonics?
drone communication is st at a few GHz
>
Reply by John Larkin●October 28, 20222022-10-28
On Fri, 28 Oct 2022 12:09:36 GMT, Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:
>On a sunny day (Fri, 28 Oct 2022 04:38:54 -0700) it happened John Larkin
><jlarkin@highlandSNIPMEtechnology.com> wrote in
><gifnlh12i7v6oscm5jqguafukd9abl6i8s@4ax.com>:
>
>>On Fri, 28 Oct 2022 04:56:20 GMT, Jan Panteltje
>><pNaonStpealmtje@yahoo.com> wrote:
>>
>>>On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
>>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>>><99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
>>>
>>>>I am struggling for every square mm of board area.
>>>>
>>>>>OTOH BAD things must happen for those parts not to be around anymore
>>>>
>>>>Parts seem to be available more lately, especially direct from TI.
>>>>
>>>>
>>>>
>>>>>
>>>>>That was to keep my drone airborne via a thin coax carrying high voltage
>>>>>transformed back to 7V at the drone:
>>>>> http://panteltje.com/pub/drone_power_small_core_test_IMG_6114.JPG
>>>>> http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
>>>>> http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
>>>>
>>>>I tested a 30 ga twisted pair of magnet wire. It failed at 1400 volts.
>>>>Wire-wrap wire must be 10 KV-ish. You'd need a clever HV downconverter
>>>>to use really light wire.
>>>>
>>>>How about a single wire to power a drone?
>>>
>>>How would that work?
>>
>>High frequency AC, working against the capacitance of the drone to the
>>world. Some tuned circuit on each end.
>>
>>>Maybe optical fiber for a high power laser? Never tried that, do have some optical fiber here..
>>
>>Power over fiber is done, but it's expensive.
>>
>>>These coaxes I use have teflon based insulation and are really good for some hundreds of volts,
>>>very light at that,
>>>The idea was to make as little RF as possible (am using about 100 kHz), put a small antenna on the drone
>>>and send the amplified received RF down the same coax (many MHz), or even use the whole coax
>>>as shortwave antenna, balloon would work too of course,
>>>just playing and investigating :-)
>>>
>>>
>>>
>>
>>Tried Micro-coax? Really tiny stuff.
>
>Did not know about that, did some web searching now
>but on the Mouser link I see max 30V rms
> https://eu.mouser.com/new/alpha-wire/alphawire-micro-coaxial-cables/
>
That's silly. Nothing breaks down at 30 volts. I expect it's good for
a few KV at least. When I was a kid I ran RG59 at 12KV. That's another
story.
>was just a test, cannot even fly a drone where I live now
>area is close to mil airport, helies and F35 and F16 all the time
>Now soon with nukes, one coming right now ;-) (sound).
> (US wants to ugrade the nukes it has stationed in Europe including here I suppose)
>
>Such a small drone wants about 70 W for flying:
> http://panteltje.com/pub/hubsan_h501s_current_test_full_throttle_IMG_6290.JPG
> more than 10 A DC at 7 V or so.
>
>So using high voltage AC to get the current in the coax down, and transforming and rectifying
>back at the drone side:
> http://panteltje.com/pub/h501s_drone_remote_power_drone_side_IMG_6278.JPG
> The propeller air stream cools the rectifier diodes and the ringcore.
>It all works :-)
> Those are special diodes and special high quality elcos,
Send DC up to avoid rectifying and filtering. There is probably some
cute little switcher chip to go from, say, 150 DC down to 7.
Reply by Jan Panteltje●October 28, 20222022-10-28
On a sunny day (Fri, 28 Oct 2022 04:38:54 -0700) it happened John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote in
<gifnlh12i7v6oscm5jqguafukd9abl6i8s@4ax.com>:
>On Fri, 28 Oct 2022 04:56:20 GMT, Jan Panteltje
><pNaonStpealmtje@yahoo.com> wrote:
>
>>On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
>><jlarkin@highlandSNIPMEtechnology.com> wrote in
>><99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
>>
>>>I am struggling for every square mm of board area.
>>>
>>>>OTOH BAD things must happen for those parts not to be around anymore
>>>
>>>Parts seem to be available more lately, especially direct from TI.
>>>
>>>
>>>
>>>>
>>>>That was to keep my drone airborne via a thin coax carrying high voltage
>>>>transformed back to 7V at the drone:
>>>> http://panteltje.com/pub/drone_power_small_core_test_IMG_6114.JPG
>>>> http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
>>>> http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
>>>
>>>I tested a 30 ga twisted pair of magnet wire. It failed at 1400 volts.
>>>Wire-wrap wire must be 10 KV-ish. You'd need a clever HV downconverter
>>>to use really light wire.
>>>
>>>How about a single wire to power a drone?
>>
>>How would that work?
>
>High frequency AC, working against the capacitance of the drone to the
>world. Some tuned circuit on each end.
>
>>Maybe optical fiber for a high power laser? Never tried that, do have some optical fiber here..
>
>Power over fiber is done, but it's expensive.
>
>>These coaxes I use have teflon based insulation and are really good for some hundreds of volts,
>>very light at that,
>>The idea was to make as little RF as possible (am using about 100 kHz), put a small antenna on the drone
>>and send the amplified received RF down the same coax (many MHz), or even use the whole coax
>>as shortwave antenna, balloon would work too of course,
>>just playing and investigating :-)
>>
>>
>>
>
>Tried Micro-coax? Really tiny stuff.
Did not know about that, did some web searching now
but on the Mouser link I see max 30V rms
https://eu.mouser.com/new/alpha-wire/alphawire-micro-coaxial-cables/
was just a test, cannot even fly a drone where I live now
area is close to mil airport, helies and F35 and F16 all the time
Now soon with nukes, one coming right now ;-) (sound).
(US wants to ugrade the nukes it has stationed in Europe including here I suppose)
Such a small drone wants about 70 W for flying:
http://panteltje.com/pub/hubsan_h501s_current_test_full_throttle_IMG_6290.JPG
more than 10 A DC at 7 V or so.
So using high voltage AC to get the current in the coax down, and transforming and rectifying
back at the drone side:
http://panteltje.com/pub/h501s_drone_remote_power_drone_side_IMG_6278.JPG
The propeller air stream cools the rectifier diodes and the ringcore.
It all works :-)
Those are special diodes and special high quality elcos,
Reply by John Larkin●October 28, 20222022-10-28
On Fri, 28 Oct 2022 04:56:20 GMT, Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:
>On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
><jlarkin@highlandSNIPMEtechnology.com> wrote in
><99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
>
>>I am struggling for every square mm of board area.
>>
>>>OTOH BAD things must happen for those parts not to be around anymore
>>
>>Parts seem to be available more lately, especially direct from TI.
>>
>>
>>
>>>
>>>That was to keep my drone airborne via a thin coax carrying high voltage
>>>transformed back to 7V at the drone:
>>> http://panteltje.com/pub/drone_power_small_core_test_IMG_6114.JPG
>>> http://panteltje.com/pub/h501s_drone_remote_power_flight_test_1_IMG_6274.JPG
>>> http://panteltje.com/pub/h501s_drone_remote_power_test_ground_control_1_IMG_6276.JPG
>>
>>I tested a 30 ga twisted pair of magnet wire. It failed at 1400 volts.
>>Wire-wrap wire must be 10 KV-ish. You'd need a clever HV downconverter
>>to use really light wire.
>>
>>How about a single wire to power a drone?
>
>How would that work?
High frequency AC, working against the capacitance of the drone to the
world. Some tuned circuit on each end.
>Maybe optical fiber for a high power laser? Never tried that, do have some optical fiber here..
Power over fiber is done, but it's expensive.
>These coaxes I use have teflon based insulation and are really good for some hundreds of volts,
>very light at that,
>The idea was to make as little RF as possible (am using about 100 kHz), put a small antenna on the drone
>and send the amplified received RF down the same coax (many MHz), or even use the whole coax
>as shortwave antenna, balloon would work too of course,
>just playing and investigating :-)
>
>
>
Tried Micro-coax? Really tiny stuff.
Reply by Jan Panteltje●October 28, 20222022-10-28
On a sunny day (Thu, 27 Oct 2022 09:33:12 -0700) it happened John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote in
<99cllhp645bv1v1qsk0hb2nccifpbecgvn@4ax.com>:
How would that work?
Maybe optical fiber for a high power laser? Never tried that, do have some optical fiber here..
These coaxes I use have teflon based insulation and are really good for some hundreds of volts,
very light at that,
The idea was to make as little RF as possible (am using about 100 kHz), put a small antenna on the drone
and send the amplified received RF down the same coax (many MHz), or even use the whole coax
as shortwave antenna, balloon would work too of course,
just playing and investigating :-)
Reply by John Larkin●October 27, 20222022-10-27
On Thu, 27 Oct 2022 20:02:03 +0100, "Kevin Aylward"
<kevinRemoveandReplaceATkevinaylward.co.uk> wrote:
>
>"Martin Brown" wrote in message news:tjap6l$4vg$1@gioia.aioe.org...
>
>On 26/10/2022 04:41, John Larkin wrote:
>> On Tue, 25 Oct 2022 21:52:46 +0100, Martin Brown
>> <'''newspam'''@nonad.co.uk> wrote:
>>
>
>>> Chances are one or more of the equations is stiff and the time step is
>>> becoming infinitessimal on one of the rapid transitions. Adding a bit of
>>> spurious dissipation 1M to ground here and there might take the edge off
>>> whatever is making it so stiff.
>>
>> We are running TI's Cadence sim and TI's encrypted switcher chip
>> models.
>>
>> We just discovered that their TPS562208 model runs about 50x faster
>> than the TPS54302 model. They are very similar chips. We have both in
>> our power supply design, one 54302 pre-regulating for three of the
>> 562208's.
>
>It might be worth building one to see if it really is inclined to squeg
>in real circuits. The sim could be telling you something important.
Yes. We just decided to do a quick-turn 4-layer board with all four
switchers. TI's spice models are insane and admittedly don't fully
model the devices.
I just need a 12 volt 9 tera-amp bench supply to run it.
https://www.dropbox.com/s/sd5640vv8et0jb1/TPS54302_Sim_JL1.jpg?raw=1
Reply by Phil Hobbs●October 27, 20222022-10-27
Kevin Aylward wrote:
>
>
>
>
> "Phil Hobbs" wrote in message
> news:4f5595a2-ab59-a6d9-ee64-a4eb8835295a@electrooptical.net...
>
> Joe Gwinn wrote:
>> On Tue, 25 Oct 2022 07:56:38 -0700, John Larkin
>
>>>> The guy running this for me has a pretty good, fairly new PC. But the
>>>> sim takes hours to simulate 10s of milliseconds, so we don't want a
>>>> modest speedup.
>>>
>>>> TI software, TI models, runs for hours. That's silly.
>>
>>> My recollection from my power-system colleagues is that this can be
>>> caused by often parasitic sub circuits with very short time constants
>>> (compared to the core circuit), so the approach was to model only the
>>> core circuit at first, then start to decorate it.
>>
>>> Joe Gwinn
>>
>> The Gear integrator is specifically designed for problems like that.
>> ("stiff systems").
>
>> Cheers
>
>> Phil Hobbs
>
> Well... :-) ......
>
> I have truly run millions of sims.......so..... (Cadence, ASIC design,
> not SuperSpice)
>
> Gear v Trap in practice really don't have much between them in terms of
> speed or convergence statistically.
Stiff systems are only one variety of ill-conditioned simulations, sure.
As the wise man said, "you can't make anything foolproof because fools
are so ingenious." ;)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com
Reply by Joe Gwinn●October 27, 20222022-10-27
On Thu, 27 Oct 2022 08:09:08 -0700, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:
>On Thu, 27 Oct 2022 13:46:47 +0100, Martin Brown
><'''newspam'''@nonad.co.uk> wrote:
>
>>On 26/10/2022 20:29, Phil Hobbs wrote:
>>> John Larkin wrote:
>>>> On Wed, 26 Oct 2022 08:56:04 +0100, Martin Brown
>>>> <'''newspam'''@nonad.co.uk> wrote:
>>>>
>>>>> On 26/10/2022 04:41, John Larkin wrote:
>>>>>> On Tue, 25 Oct 2022 21:52:46 +0100, Martin Brown
>>>>>> <'''newspam'''@nonad.co.uk> wrote:
>>>>>>
>>>>>
>>>>>>> Chances are one or more of the equations is stiff and the time step is
>>>>>>> becoming infinitessimal on one of the rapid transitions. Adding a
>>>>>>> bit of
>>>>>>> spurious dissipation 1M to ground here and there might take the
>>>>>>> edge off
>>>>>>> whatever is making it so stiff.
>>>>>>
>>>>>> We are running TI's Cadence sim and TI's encrypted switcher chip
>>>>>> models.
>>>>>>
>>>>>> We just discovered that their TPS562208 model runs about 50x faster
>>>>>> than the TPS54302 model. They are very similar chips. We have both in
>>>>>> our power supply design, one 54302 pre-regulating for three of the
>>>>>> 562208's.
>>>>>
>>>>> It might be worth building one to see if it really is inclined to squeg
>>>>> in real circuits. The sim could be telling you something important.
>>>>
>>>> If we can't reasonably sim it, we'll build it. I can imagine the three
>>>> secondary switchers, negative impedance loads, making the first one
>>>> oscillate. That's not a risk we want on our new delay generator.
>>>>
>>>> Each reg needs output caps of unknown value, and feedforward caps in
>>>> its fedback divider. May as well get all that right.
>>
>>What might break the deadlock for computation is add a small series
>>resistance to the capacitance after the first regulator to low pass
>>filter it. The trick will be to find something modest enough to not
>>affect the predictions much but sufficient to compute it more easily.
>>
>>You might have to do something like that IRL too.
>>
>>I expect they never expected you to daisy chain them back to back like
>>that and the output of the first one really doesn't like facing the
>>negative impedance dynamic load. Classic way to make an oscillator.
>>
>>>>> Parasitic things with ridiculously high Q can ring if provoked which is
>>>>> why adding the odd spurious dissipative resistor to certain key nodes
>>>>> sometimes helps instil good behaviour. Jeroen has made the same point.
>>>>
>>>> I wish TI knew all that.
>>>>
>>>
>>> I suspect they give their modelers tight budgets for how many hours they
>>> can spend per model.
>>
>>And that they never considered the output of one driving the inputs of
>>several others.
>
>Here's what I have so far. The first switcher sees a complex load,
>some of which is negative impedance. We'll split the board into noisy
>and quiet "Q" halves with ferrite beads bridging the power pours. That
>makes the impedances yet more interesting.
>
>https://www.dropbox.com/s/pklyt3mrlvf3ewm/28S662A7_power.pdf?dl=0
>
>I hope it's not that ratty in real life, and is somewhat more
>efficient.
The power-supply guys I knew had no problem getting cascaded switchers
(and linear final regulators) to work. They simulated the whole
combined assembly of voltage regulators, and paid a lot of attention
to loop filters and cascade filters. Not to mention cables between,
if present. The whole circuit. All this being simulated using
LTspice, but with proprietary locally developed models.
>This being 2022, the design is dominated by what we can get.
>
>We have managed to get the TI switchers to work in LT Spice at
>bearable speeds, tens of minutes per run instead of overnight. I don't
>trust the results, especially for the first switcher, the TPS54302.
>
>https://www.dropbox.com/s/sd5640vv8et0jb1/TPS54302_Sim_JL1.jpg?raw=1
>
>The sim log file is full of complaints about bad curly brackets and
>such. I didn't draw any curly brackets.
>
>Switchers driving switchers is common. Nobody likes going from 24
>volts to 1 volt, even if you can get the parts.
>
>Go to the TI or ADI web site and look at New Products. It's mind
>boggling. How can they support, and make good models for, all those
>parts? How long will they keep making them?