Having fun at 350 amps

W

Winfield Hill

Guest
Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.



--
Thanks,
- Win
 
On 2020-01-05 21:29, Winfield Hill wrote:
Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.
Click to expand...

Sounds like fun, but a bit far afield for me. Good on you for posting
it though!

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.net
http://hobbs-eo.com
 
Phil Hobbs wrote...
On 2020-01-05 21:29, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.

Sounds like fun, but a bit far afield for me.
Good on you for posting it though!
Click to expand...

Consider, 250kW EV chargers run with currents
over 500A, and that's continuous. Do we know
how they work, familiar with the circuitry?
Develop a little hands-on exposure, with free
PCBs and low-cost parts. Yes, we're talking
short current pulses, but you can get actual
bench and 'scope experience with high di/dt.
Email me your shipping address for free PCBs.


--
Thanks,
- Win
 
On 2020-01-06 09:22, Winfield Hill wrote:
Phil Hobbs wrote...

On 2020-01-05 21:29, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.

Sounds like fun, but a bit far afield for me.
Good on you for posting it though!

Consider, 250kW EV chargers run with currents
over 500A, and that's continuous. Do we know
how they work, familiar with the circuitry?
Develop a little hands-on exposure, with free
PCBs and low-cost parts. Yes, we're talking
short current pulses, but you can get actual
bench and 'scope experience with high di/dt.
Email me your shipping address for free PCBs.
Click to expand...

Thanks, Win, but as I say it's a bit far afield, so it would probably
just sit there on my bench. Plus I'm most unlikely to buy an electric
car any time soon, or build a charger if I did.

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.net
http://hobbs-eo.com
 
Phil Hobbs wrote...
Winfield Hill wrote:
Phil Hobbs wrote...
On 2020-01-05 21:29, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.

Sounds like fun, but a bit far afield for me.
Good on you for posting it though!

Consider, 250kW EV chargers run with currents
over 500A, and that's continuous. Do we know
how they work, familiar with the circuitry?
Develop a little hands-on exposure, with free
PCBs and low-cost parts. Yes, we're talking
short current pulses, but you can get actual
bench and 'scope experience with high di/dt.
Email me your shipping address for free PCBs.

Thanks, Win, but as I say it's a bit far afield,
so it would probably just sit there on my bench.
Plus I'm most unlikely to buy an electric car
any time soon, or build a charger if I did.
Click to expand...

Thanks, Phil, Yes, I understand you're out, but
I'm making a pitch to others. There's a pot on
the board so you can adjust the current, from 5
or 10A upwards. Current pulses are very useful
to test resistors, diodes, zeners, capacitors,
inductors, MOSFETs, etc. Voltage pulses, such
as you easily get from a switched MOSFET, don't
work well, because V = L di/dt shields the part
from high currents, until your wiring inductance
charges up. Small L is a big deal at high di/dt.

The design uses specialized parts to reach 200A
and above, but you can probably make it work to
25, 50 or 100A with ordinary on-hand parts.


--
Thanks,
- Win
 
On 5 Jan 2020 18:29:30 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.
Click to expand...

Here's a little laser driver

https://www.dropbox.com/s/cra2gsafbrtxfuz/D140_Top.JPG?raw=1

that was intended to drive a bar laser to pump a YAG. It can put 200
amps into a 25 volt stack at low rep-rates

We haven't sold many, because it's not horribly difficult to close a
relatively slow current loop around a mosfet. It becomes a
race-to-the-bottom price war, or the customer looks at the first
article and says, hey, we can do that ourselves. We have more luck
selling picosecond stuff at lower currents.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
Sorry for the top-post. DropBox updates:
Photos of little RIS-796 PCB and new measurements.
Scope traces of nice pulses at 400, 500 and 560A.
(These are with a 15mR load and 35-volt supply.
Way more than the big LEDs can handle, but fun.)
Also updated file sets for RIS-796 and RIS-796A.

https://www.dropbox.com/sh/tcmiahzzughadfk/AABtgFDy01cuTDWDRjujP6jva?dl=1

Free PCBs start mailing out today, get your set
of two by sending me an email. Speff is gonna
do 0.5us photo flash with 100W COB LED arrays,
with HV parts, should work. Do the fun stuff!

Winfield Hill wrote...
Phil Hobbs wrote...
Winfield Hill wrote:
Phil Hobbs wrote...
On 2020-01-05 21:29, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.

Sounds like fun, but a bit far afield for me.
Good on you for posting it though!

Consider, 250kW EV chargers run with currents
over 500A, and that's continuous. Do we know
how they work, familiar with the circuitry?
Develop a little hands-on exposure, with free
PCBs and low-cost parts. Yes, we're talking
short current pulses, but you can get actual
bench and 'scope experience with high di/dt.
Email me your shipping address for free PCBs.

Thanks, Win, but as I say it's a bit far afield,
so it would probably just sit there on my bench.
Plus I'm most unlikely to buy an electric car
any time soon, or build a charger if I did.

Thanks, Phil, Yes, I understand you're out, but
I'm making a pitch to others. There's a pot on
the board so you can adjust the current, from 5
or 10A upwards. Current pulses are very useful
to test resistors, diodes, zeners, capacitors,
inductors, MOSFETs, etc. Voltage pulses, such
as you easily get from a switched MOSFET, don't
work well, because V = L di/dt shields the part
from high currents, until your wiring inductance
charges up. Small L is a big deal at high di/dt.

The design uses specialized parts to reach 200A
and above, but you can probably make it work to
25, 50 or 100A with ordinary on-hand parts.
Click to expand...

--
Thanks,
- Win
 
Winfield Hill wrote...
Free PCBs start mailing out today, get your set
of two by sending me an email.
Click to expand...

Confirming, free shipping worldwide.


--
Thanks,
- Win
 
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qv56nu0275p@drn.newsguy.com:

Winfield Hill wrote...

Free PCBs start mailing out today, get your set
of two by sending me an email.

Confirming, free shipping worldwide.
Click to expand...

That is not the stuff they used to contaminate telephone poles with is
it? ;-)
 
On Monday, January 6, 2020 at 4:08:50 PM UTC, jla...@highlandsniptechnology.com wrote:
On 5 Jan 2020 18:29:30 -0800, Winfield Hill <winfieldhill@yahoo.com
wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.


Here's a little laser driver

https://www.dropbox.com/s/cra2gsafbrtxfuz/D140_Top.JPG?raw=1

that was intended to drive a bar laser to pump a YAG. It can put 200
amps into a 25 volt stack at low rep-rates

We haven't sold many, because it's not horribly difficult to close a
relatively slow current loop around a mosfet. It becomes a
race-to-the-bottom price war, or the customer looks at the first
article and says, hey, we can do that ourselves. We have more luck
selling picosecond stuff at lower currents.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics
Click to expand...

Win, Sending that many amps via a pair of molybdenum electrodes is nice way to weld small copper wires to a pcb, no solder. (limit V to about 1.0). A good choice when you need a "clean" assembly.
Cheers, Rich S.
 
On Thursday, January 9, 2020 at 5:43:00 AM UTC+11, DecadentLinux...@decadence.org wrote:
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qv56nu0275p@drn.newsguy.com:

Winfield Hill wrote...

Free PCBs start mailing out today, get your set
of two by sending me an email.

Confirming, free shipping worldwide.

That is not the stuff they used to contaminate telephone poles with is
it? ;-)
Click to expand...

Polychlorinated Biphenyls?

https://en.wikipedia.org/wiki/Polychlorinated_biphenyl

Win was talking about printed circuit boards, which are rather more enviroment-friendly.

--
Bill Sloman, Sydney
 
Bill Sloman <bill.sloman@ieee.org> wrote in
news:073a224a-a952-4267-b2fa-a0595e423268@googlegroups.com:

On Thursday, January 9, 2020 at 5:43:00 AM UTC+11,
DecadentLinux...@decadence.org wrote:
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qv56nu0275p@drn.newsguy.com:

Winfield Hill wrote...

Free PCBs start mailing out today, get your set
of two by sending me an email.

Confirming, free shipping worldwide.

That is not the stuff they used to contaminate telephone poles
with is it? ;-)

Polychlorinated Biphenyls?

https://en.wikipedia.org/wiki/Polychlorinated_biphenyl

Win was talking about printed circuit boards, which are rather
more enviroment-friendly.
Click to expand...

It was a joke you retarded twerp.

Damn you are stupid.
 
Rich S wrote...
On 5 Jan 2020, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Whattsa matter wid y'all blokes? Have fun,
get with the program, email for free PCBs.
Make your own 200A to 500A pulses soon!

Circuit includes easy current measurement,
which I used to take 200A scope pics on link.

Get full detailed engineering info links at
"200A 6kW sub-us analog-controlled pulses".

Many of us have instruments, power supplies,
SMUs, curve tracers, etc., that take pulsed
measurements to 10A. Coming up soon on the
sub-us analog-controlled pulses list: Make
a 10, 20 or 40x current multiplier, so those
instruments can take measurements to 400A.
Get started now, so you can play along later.

Win, Sending that many amps via a pair of molybdenum
electrodes is nice way to weld small copper wires
to a pcb, no solder. (limit V to about 1.0). A
good choice when you need a "clean" assembly.
Click to expand...

BTW, Rob and I have extended our tests to much
higher currents. Do you think a welding scheme
like that would benefit particularly from precise
current and pulse-length control? What's the
story about limiting the maximum voltage?


--
Thanks,
- Win
 
On Sunday, January 19, 2020 at 8:23:25 AM UTC-5, Winfield Hill wrote:
BTW, Rob and I have extended our tests to much
higher currents. Do you think a welding scheme
like that would benefit particularly from precise
current and pulse-length control? What's the
story about limiting the maximum voltage?
Click to expand...

Programmable current would be nice for surface spot welding.
 
"Michael Terrell" <terrell.michael.a@gmail.com> wrote in message
news:c6e7a42d-a5c5-4038-8006-d2d4b2436513@googlegroups.com...
On Sunday, January 19, 2020 at 8:23:25 AM UTC-5, Winfield Hill wrote:

BTW, Rob and I have extended our tests to much
higher currents. Do you think a welding scheme
like that would benefit particularly from precise
current and pulse-length control? What's the
story about limiting the maximum voltage?


Programmable current would be nice for surface spot welding.
Click to expand...

Y'mean this?
https://hackaday.com/2017/09/16/a-battery-tab-welder-with-real-control-issues/

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/
 
On Sunday, January 19, 2020 at 6:35:43 PM UTC-5, Tim Williams wrote:
"Michael Terrell" wrote in message
news:c6e7a42d-a5c5-4038-8006-d2d4b2436513@googlegroups.com...
On Sunday, January 19, 2020 at 8:23:25 AM UTC-5, Winfield Hill wrote:

BTW, Rob and I have extended our tests to much
higher currents. Do you think a welding scheme
like that would benefit particularly from precise
current and pulse-length control? What's the
story about limiting the maximum voltage?


Programmable current would be nice for surface spot welding.

Y'mean this?
https://hackaday.com/2017/09/16/a-battery-tab-welder-with-real-control-issues/

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/
Click to expand...

Looks interesting. Certainly better than the improvised high curent pulse generator i used back in the early '80s. I had just installed a new NiCad battery pack in a Tektronix TDR. I told our techs that it had to be fully charged before the first use. One took it anyway, and left it in his work truck over the weekend, with it turned on. All of the cells were shorted in that ~ $300 battery pack. I couldn't order a second one right away, and we only had the one TDR. I made the jerk hold the opened battery pack as I used a pair of jumper cables from his truck battery to blow out the whiskers as I reminded him that it could explode, each time I touched a cell. It was still working, over three years later. :)
 
On Sunday, January 19, 2020 at 9:23:50 PM UTC+11, DecadentLinux...@decadence.org wrote:
Bill Sloman <bill.sloman@ieee.org> wrote in
news:073a224a-a952-4267-b2fa-a0595e423268@googlegroups.com:

On Thursday, January 9, 2020 at 5:43:00 AM UTC+11,
DecadentLinux...@decadence.org wrote:
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qv56nu0275p@drn.newsguy.com:

Winfield Hill wrote...

Free PCBs start mailing out today, get your set
of two by sending me an email.

Confirming, free shipping worldwide.

That is not the stuff they used to contaminate telephone poles
with is it? ;-)

Polychlorinated Biphenyls?

https://en.wikipedia.org/wiki/Polychlorinated_biphenyl

Win was talking about printed circuit boards, which are rather
more enviroment-friendly.

It was a joke you retarded twerp.
Click to expand...

Not one that deserved to treated as a joke. Acronyms are frequently ambiguous, and making a joke out of the ambiguity takes more effort than you put in.

The retarded twerp here is you, wasting bandwidth with a poor excuse for a joke.

> Damn you are stupid.

You do like to think so, but - as so you frequently do - you have misread the situation and drawn the wrong conclusion.

--
Bill Sloman, Sydney
 
Tim Williams wrote...
"Michael Terrell" <terrell.michael.a@gmail.com> wrote in message
news:c6e7a42d-a5c5-4038-8006-d2d4b2436513@googlegroups.com...
On Sunday, January 19, 2020 at 8:23:25 AM UTC-5, Winfield Hill wrote:

BTW, Rob and I have extended our tests to much
higher currents. Do you think a welding scheme
like that would benefit particularly from precise
current and pulse-length control? What's the
story about limiting the maximum voltage?


Programmable current would be nice for surface spot welding.

Y'mean this?
https://hackaday.com/2017/09/16/a-battery-tab-welder-with-real-control-issues/
Click to expand...

His six MOSFETs can handle about 4x more energy
absorption in 1ms, than my big one with its heat
sink, but for Frank Boeh's long pulses, say 55ms,
they're a bit closer to equal, but his esr levels
are much lower, and therefore the maximum currents
with a given supply voltage are much higher. He's
developed a very capable measurement and control
system, with accessories, ideal for spot welding.

On the linked site, https://www.keenlab.de/
click on kWeld – Next level battery spot welder.


--
Thanks,
- Win
 
Was, Having fun at 350 amps

Winfield Hill wrote...
On 5 Jan 2020, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.
Click to expand...

I've done 500A with a 20mR source resistor, and
Rob has done 600A with a 10mR resistor. But we
can use 5mR or lower, and apparently the MOSFET
can handle over 1000A.** I've been wondering how
they get datasheet Transfer Characteristics plots
to 200A, etc, my SMU only goes to 10A. And hey,
we'd like to get MOSFET operating data up to 1kA.

Aha, I realized we can easily do that. The next
rev of RIS-796A (analog-control pulser) has 5mR
resistor standard (1.0V at 200A), and changing
a few parts lets it work to 1kA. The missing
ingredient was an AD8274 difference amplifier,
taking Vgs and translating this to ground, for
precision measurement. Step current in 50 or
100A steps, and make measured Id vs Vgs graphs.
Calculate the drain voltage and pulse duration
to raise Tj to 175C, and get a high-temp plot.
I'll be posting details shortly in a new thread.

** Our HUF75652 MOSFET can handle 33kW for 20us.
We can make pulses as short as 2us.


--
Thanks,
- Win
 
On 1 Feb 2020 11:49:22 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Was, Having fun at 350 amps

Winfield Hill wrote...

On 5 Jan 2020, Winfield Hill wrote:

Rob Legg has returned from a holiday break,
and has stepped up his prototype tests to
350 amps. I hope to try for 400A tomorrow.

I've done 500A with a 20mR source resistor, and
Rob has done 600A with a 10mR resistor. But we
can use 5mR or lower, and apparently the MOSFET
can handle over 1000A.** I've been wondering how
they get datasheet Transfer Characteristics plots
to 200A, etc, my SMU only goes to 10A. And hey,
we'd like to get MOSFET operating data up to 1kA.

Aha, I realized we can easily do that. The next
rev of RIS-796A (analog-control pulser) has 5mR
resistor standard (1.0V at 200A), and changing
a few parts lets it work to 1kA. The missing
ingredient was an AD8274 difference amplifier,
taking Vgs and translating this to ground, for
precision measurement. Step current in 50 or
100A steps, and make measured Id vs Vgs graphs.
Calculate the drain voltage and pulse duration
to raise Tj to 175C, and get a high-temp plot.
I'll be posting details shortly in a new thread.

** Our HUF75652 MOSFET can handle 33kW for 20us.
We can make pulses as short as 2us.
Click to expand...

How about a lower RdsOn FET ? A 7 lead part, maybe the Infineon
IPT015N10N5 100V 1.5 m Ohm I think it is also a bit larger die.
Digikey has a bunch of them.

For high current shunts, 500A @ 50 mV is typically used or 1000A @ 100
mA shunts.

http://www.cshunt.com/pdf/c.pdf for Canadian Shunt 100 micro-Ohms

DELTEC is mainly who we use. Should be able to get these for less
than $20 or so.
 
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