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Looking to build a transient generator

A product I am designing requires a series of lab tests to judge
robustness against electrical transients.

One such test is to charge up a 100mH inductor in series with a 4 ohm
load (4ohm load to ground). Then, once the inductor is fully charged,
open the supply current to it from the high side. The resulting field
collapse will produce a substantial negative going voltage spike.

The circuit goes V+ to switch to inductor to resistor to ground.

The DUT is placed in parallel with the inductor/resistor series
combination, at the open end of the circuit once the switch is opened.

My question: I want to prolong the duration of the pulse by a factor
of 10x to create a more destructive burst of energy.

E=.5*L*I^2

I want to keep DC current through the branch the same. With that
said, one would reason I would need to bump up my inductance by a
factor of 10. This would require a 1H inductor!

Is it practical to find such a large inductance? Any ideas?

Thank you

Gerb
 
P

Phil Allison

Jan 1, 1970
0
A product I am designing requires a series of lab tests to judge
robustness against electrical transients.

One such test is to charge up a 100mH inductor in series with a 4 ohm
load (4ohm load to ground). Then, once the inductor is fully charged,
open the supply current to it from the high side. The resulting field
collapse will produce a substantial negative going voltage spike.

The circuit goes V+ to switch to inductor to resistor to ground.

The DUT is placed in parallel with the inductor/resistor series
combination, at the open end of the circuit once the switch is opened.

My question: I want to prolong the duration of the pulse by a factor
of 10x to create a more destructive burst of energy.

E=.5*L*I^2

I want to keep DC current through the branch the same. With that
said, one would reason I would need to bump up my inductance by a
factor of 10. This would require a 1H inductor!

Is it practical to find such a large inductance? Any ideas?


** All depends on what DC current you are testing at.

Why not tell us ?



...... Phil
 

neon

Oct 21, 2006
1,325
Joined
Oct 21, 2006
Messages
1,325
A product I am designing requires a series of lab tests to judge
robustness against electrical transients.

One such test is to charge up a 100mH inductor in series with a 4 ohm
load (4ohm load to ground). Then, once the inductor is fully charged,
open the supply current to it from the high side. The resulting field
collapse will produce a substantial negative going voltage spike.

The circuit goes V+ to switch to inductor to resistor to ground.

The DUT is placed in parallel with the inductor/resistor series
combination, at the open end of the circuit once the switch is opened.

My question: I want to prolong the duration of the pulse by a factor
of 10x to create a more destructive burst of energy.

E=.5*L*I^2

I want to keep DC current through the branch the same. With that
said, one would reason I would need to bump up my inductance by a
factor of 10. This would require a 1H inductor!

Is it practical to find such a large inductance? Any ideas?

Thank you

Gerb
go to the junk yard and get a car coil about 80mw power. that will not kill you but will surely get you mad.
 
<[email protected]>











** All depends on what DC current you are testing at.

   Why not tell us ?

.....    Phil- Hide quoted text -

- Show quoted text -

You know Phil, no matter how hard I try, I always end up leaving out
some vital detail. Thanks for helping me out :).

I would like to pass 3.2A +/- 200mA through the inductor. I realize
that as the inductor gains in size, so will its series DC resistance.
Therefore, at one point I might need to adjust my series resistance to
keep the branch current where I want it. This will result in a very
large inductor. Digikey does not carry these :(.

Gerb
 
P

Phil Allison

Jan 1, 1970
0
<[email protected]
"Phil Allison"
** All depends on what DC current you are testing at.

Why not tell us ?

You know Phil, no matter how hard I try, I always end up leaving out
some vital detail. Thanks for helping me out :).

I would like to pass 3.2A +/- 200mA through the inductor. I realize
that as the inductor gains in size, so will its series DC resistance.
Therefore, at one point I might need to adjust my series resistance to
keep the branch current where I want it. This will result in a very
large inductor. Digikey does not carry these :(.


** Hmmmm -

a 3.5 amp rated inductor of say 1 Henry would weigh more than I care to
lift.



...... Phil
 
<[email protected]
"Phil Allison"










You know Phil, no matter how hard I try, I always end up leaving out
some vital detail.  Thanks for helping me out :).

I would like to pass 3.2A +/- 200mA through the inductor.  I realize
that as the inductor gains in size, so will its series DC resistance.
Therefore, at one point I might need to adjust my series resistance to
keep the branch current where I want it.  This will result in a very
large inductor.  Digikey does not carry these :(.

**  Hmmmm  -

 a 3.5 amp rated inductor of say 1 Henry would weigh more than I care to
lift.

.....    Phil- Hide quoted text -

- Show quoted text -

I understand its not going to be small nor light wieght. However, I
need to come up with something in close proximity to what I require.
Ideas anyone?

Gerb
 
P

Phil Allison

Jan 1, 1970
0
"Tim Wescott"
I'd check out power transformer companies -- Hammond and Peter W. Dahl
come to mind.

** Hammond have inductors for high voltage PSUs of up to 10H - but none
come anywhere near the OP's 3.5 amp requirement.

You may be able to get something made custom, or find a power transformer
with a primary winding of around 1H.


** Nonsense.

Transformer primaries are NOT efficient inductors and will SATURATE long
before 3.5 amps is reached.

You may also be able to start with a big-iron power transformer and rewind
it for your 1H.


** Need to start with a tranny of several kW rating and the lams have to be
re-stacked to create an appropriate air gap.

Big job.


...... Phil
 
P

Phil Allison

Jan 1, 1970
0
"Tim Wescott Fuckwit "
"Check with" != "look in catalog like a twit".
"Check with" == "call nice Hammond lady on the phone and ask".


** **** you - you pathetic asshole.

Why thank you, Phil. It's so nice to be educated by you today.


** **** you - you pathetic asshole.

So, there are no transformers anywhere in this wide world


** **** you - you pathetic asshole.

The OP has not got access to every tranny in the WHOLE world.

FUCKWIT !!!!


Is 'SATURATE' the same as 'saturate',


** **** you - you pathetic ASD fucked asshole.

So those transformers that PGE uses, that are as big as a small house,
can't take 3.5ADC in any of their windings, and couldn't even if they were
rewound to 1H?


** **** you - you pathetic ASD fucked asshole.

Gee. I learn something new every single day!


** **** you - you pathetic ASD fucked asshole.



** The OP, like many who post here, did NOT need his idiotic Q answering in
the LITERAL way ASD fucked morons like YOU always do.

He needs to think of another way to do his test.

While YOU need to get a brain transplant - even a chimp's brain would be
an improvement.




...... Phil
 
What sort oftransientvoltages do you foresee?  Could you get by with a
HV supply and a controller, or is that cheating?

--

Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says..
See details athttp://www.wescottdesign.com/actfes/actfes.html- Hide quoted text -

- Show quoted text -

I want to create a -400V transient (switching the inductor high side)
with a time contant of approximately 10mS. I have the option of
taking this to a local EMC lab that has the capability of generating
this pulse. However, I might want to run a few hundred products
through this test. EMC lab time is expensive. For reasons I would
rather not go into, I'd like to do this "on the cheap side". Thus,
building my own equipment from scratch and surplus bits.

I found two companies willing to construct inductors for me. The
problem, the cheaper of the two wanted $2500USD. I currently don't
have that type of budget. I assume the solution you mentioed above
(High voltage supply and controller) will cost even more.

Thank you,

Gerb
 
Do you really need the inductance circuit to test
the DUT?  If you want a more destructive pulse,
how about creating the shape you want with an
arbitrary waveform generator or even with your
original inductor circuit, then using it to
control a big amp or power supply applied to your
DUT?

Best regards,

Bob Masta

              DAQARTA  v4.50
   Data AcQuisition And Real-Time Analysis
             www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
           FREE Signal Generator
        Science with your sound card!- Hide quoted text -

- Show quoted text -

I've looked into what the equipment I would need to do this would
cost. It is just not feasible.
 
P

Phil Allison

Jan 1, 1970
0
"Tim Wescott PIG ARROGANT Fuckwit "
Hells bells and little birdies,


** What a fucking ARSEWIPE you are - Wescuntt.


Sometimes,


** What is sometimes the case is not THIS time !

All you ever SPEW is irrelevant & IRRATIONAL SHIT !!


I'm willing let him use _his_ judgment as to whether he's taking the
right approach,


** Spoken like a completely narcissistic FOOL.

All you are Wescuntt is a CLUELESS TWAT

dishing out 100 % STUPID advice.


YOU need to get a brain transplant - even a DEAD chimp's brain would be
an improvement.

Piss off - TURD BRAIN !!!




....... Phil
 
 "Tim Wescott  PIG ARROGANT  Fuckwit "





** What a  fucking  ARSEWIPE  you are  -   Wescuntt.



** What is sometimes the case is not  THIS  time !

All you ever SPEW is irrelevant &  IRRATIONAL   SHIT  !!


**  Spoken like a completely narcissistic  FOOL.

All you are Wescuntt is a  CLUELESS   TWAT

  dishing out  100 %  STUPID   advice.

YOU  need to get a brain transplant  -  even a  DEAD  chimp's brain would be
 an improvement.

Piss off  -  TURD  BRAIN  !!!

......  Phil

Gentlemen. May I ask why this thread has turned into nothing but one
big pissing match? It seems you don't have much respect for each
other. That is OK. But please take the arguement elsewhere.

Thank you,

Gerb
 
The opinion of certain vulgar individuals notwithstanding, I still think
it's worth looking into kit-bashing a transformer.  For $2500 you can
spend a considerable amount of time rebuilding and rewinding a surplus
core and still come out ahead.

I'd look to the coils that Hammond sells purely for the purpose of
getting a weight vs. energy number, then think about (a) whether I want
that big of a lump of steel cluttering up my shop, and (b) where in heck
I could get a core that big for cheap.

Come to think of it, why look for one great gazonga of a thing, when you
can build it yourself out of smaller chokes?

Just from the Antique Radio Supply catalog, I see that you could put
together 10 10H x 500mA chokes in parallel for a 1H, 5A choke.  It'd
weigh 210lbs less your frame, and cost you 10 x $68.45.  That's a heck
of a lot less than your $2500.  Hammond also has a 100mH, 5A, 14lb choke
(the 195T5) that you could string in series, but Antique Radio Supply
doesn't list it (and if you're getting 10, you'd be better off getting
it straight from Hammond anyway).

Check to make sure you're not getting a "swinging" choke, unless a
swinging choke is what you want.

--

Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says..
See details athttp://www.wescottdesign.com/actfes/actfes.html- Hide quoted text -

- Show quoted text -

Thank you. Now this is more inside my budget :).

Gerb
 
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