Is there a device that...?

M

Mark Folsom

Guest
Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom
 
"Mark Folsom" <folsom_snip_man@redshift.com> writes:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom
capacitor.

but I think you meant something more detailed.
--
Steven D. Swift, novatech@eskimo.com, http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA
 
On 9 Dec 2003 20:52:51 GMT, novatech@eskimo.com (Steven Swift) wrote:

"Mark Folsom" <folsom_snip_man@redshift.com> writes:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.
What is it that you do at Novatech?

--

Boris Mohar
 
"Steven Swift" <novatech@eskimo.com> wrote in message
news:br5cn3$q2u$1@eskinews.eskimo.com...
"Mark Folsom" <folsom_snip_man@redshift.com> writes:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.
A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Mark Folsom
 
In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.
Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.

Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.

Without knowing more about your application and needs, it's going to
be difficult for anyone to give you an answer precise enough to suit
your needs.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
"Dave Platt" <dplatt@radagast.org> wrote in message
news:vtcige6k0q6m4b@corp.supernews.com...
In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is
applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.
For the first 100 to 1000ms of operation, the powered circuit draws about 5
microamps. The initial voltage, from which we would like to protect the
powered circuit, could be from 50 to 60 volts. After about 50 microseconds,
drawing off a tiny bit of charge will bring the voltage down to half of its
initial value, which is acceptable to the powered circuit. Since we need
this to be tiny, an inductor is unsuitable.

Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.
What I envisioned, if only we had room, is an RC circuit connected through a
zener to the gate of an SCR. The capacitor would charge until it reached
the threshold of the zener and then switch the SCR on--and it would draw off
the bit of charge needed to pull the voltage down. A small surface mount
chip with this set of components or an operational equivalent would help a
lot.

Mark Folsom
 
Whoops, in my attempt at "wit" I missed the point. Sorry.

But, all wit aside, you can buy "reset generators" that take one cap to
set the delay time. A SOT-23+cap=100uS delay.

"Mark Folsom" <folsom_snip_man@redshift.com> writes:

"Steven Swift" <novatech@eskimo.com> wrote in message
news:br5cn3$q2u$1@eskinews.eskimo.com...
"Mark Folsom" <folsom_snip_man@redshift.com> writes:

Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Mark Folsom

--
Steven D. Swift, novatech@eskimo.com, http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA
 
Mark Folsom wrote:
"Dave Platt" <dplatt@radagast.org> wrote in message
news:vtcige6k0q6m4b@corp.supernews.com...

In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:


Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is

applied,

like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.


For the first 100 to 1000ms of operation, the powered circuit draws about 5
microamps. The initial voltage, from which we would like to protect the
powered circuit, could be from 50 to 60 volts. After about 50 microseconds,
drawing off a tiny bit of charge will bring the voltage down to half of its
initial value, which is acceptable to the powered circuit. Since we need
this to be tiny, an inductor is unsuitable.


Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.


What I envisioned, if only we had room, is an RC circuit connected through a
zener to the gate of an SCR. The capacitor would charge until it reached
the threshold of the zener and then switch the SCR on--and it would draw off
the bit of charge needed to pull the voltage down. A small surface mount
chip with this set of components or an operational equivalent would help a
lot.

Mark Folsom
7 posts in the thread and it's still not at all clear what you want.
Way too many "about", 10:1 time interval range, tiny bit of charge...

Just clamp the voltage with a zener.
mike

--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
novatech@eskimo.com (Steven Swift) wrote:
"Mark Folsom" <folsom_snip_man@redshift.com> writes:
Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

capacitor.
Well, inductor would be closer, but the OP is probably looking for
some kind of avalanche device. OTOH, 100 uS is a pretty long time, in
the grand scheme of things, so maybe some kind of time delay circuit.

It _would_ be helpful to know what the OP had in mind for this part to
_do_...

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com
 
"mike" <spamme0@juno.com> wrote in message news:3FD66A52.7020609@juno.com...
Mark Folsom wrote:
"Dave Platt" <dplatt@radagast.org> wrote in message
news:vtcige6k0q6m4b@corp.supernews.com...

In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:


Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is

applied,

like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.


For the first 100 to 1000ms of operation, the powered circuit draws
about 5
microamps. The initial voltage, from which we would like to protect the
powered circuit, could be from 50 to 60 volts. After about 50
microseconds,
drawing off a tiny bit of charge will bring the voltage down to half of
its
initial value, which is acceptable to the powered circuit. Since we
need
this to be tiny, an inductor is unsuitable.


Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.


What I envisioned, if only we had room, is an RC circuit connected
through a
zener to the gate of an SCR. The capacitor would charge until it
reached
the threshold of the zener and then switch the SCR on--and it would draw
off
the bit of charge needed to pull the voltage down. A small surface
mount
chip with this set of components or an operational equivalent would help
a
lot.

Mark Folsom



7 posts in the thread and it's still not at all clear what you want.
Way too many "about", 10:1 time interval range, tiny bit of charge...

Just clamp the voltage with a zener.
mike
I think it's pretty clear what I want. If there's something specific you
don't understand, maybe you could ask. Unlike most electronic applications,
this one needs to avoid throwing away the energy that would be lost in
clamping with a zener. I may seem stupid to you, but I already thought of
clamping with a zener.

If you think 7 posts is too much, you can stop reading.

Thanks,

Mark Folsom
 
"Mark Folsom" <folsom_snip_man@redshift.com> writes:

Okay, I see what you need.

I'd use a tiny mosfet with an RC on the gate, along with a diode to make
sure the gate cap is reset upon power down. The bad news is that this won't
work if your power comes up slowly. You'll have to design the RC time constant
for your anticipated slew rate.

I still like the idea of a micro-power reset generator, and then use it to
drive a Mosfet. Maxim, et al make these things. You can also look for "hot
switch controllers" which are important to make hot plug and play work. USB
has these devices.

Am I on the right track now?

Sorry about the original flippant remark.

Steve.
--
Steven D. Swift, novatech@eskimo.com, http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA
 
On Tue, 9 Dec 2003 17:01:24 -0800, "Mark Folsom" <folsom_snip_man@redshift.com>
wrote:



I think it's pretty clear what I want. If there's something specific you
don't understand, maybe you could ask. Unlike most electronic applications,
this one needs to avoid throwing away the energy that would be lost in
clamping with a zener. I may seem stupid to you, but I already thought of
clamping with a zener.

If you think 7 posts is too much, you can stop reading.

Thanks,

Mark Folsom
Mark,

It might be clear to you what you want but it is not clear to us. Perhaps it
would be more useful to also describe what you have in more detail.
That bit about "throwing away energy" catches attention. You might have a good
reason not to waste any, but sharing that with us might help in coming up with
a practical solution. How much current do you want the device to switch and how
much power is it allowed to dissipate doe to it s finite on resistance?
sci.physics could not help yo because they invent this stuff. We use it. Unlike
sci.physics, playing ten questions is out of the question. Spill your guts and
you will get help. sci.electronics.design is another place to ask.


--

Boris Mohar
 
Mark Folsom wrote:
"mike" <spamme0@juno.com> wrote in message news:3FD66A52.7020609@juno.com...

Mark Folsom wrote:

"Dave Platt" <dplatt@radagast.org> wrote in message
news:vtcige6k0q6m4b@corp.supernews.com...


In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:



Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is

applied,


like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.


For the first 100 to 1000ms of operation, the powered circuit draws

about 5

microamps. The initial voltage, from which we would like to protect the
powered circuit, could be from 50 to 60 volts. After about 50

microseconds,

drawing off a tiny bit of charge will bring the voltage down to half of

its

initial value, which is acceptable to the powered circuit. Since we

need

this to be tiny, an inductor is unsuitable.



Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.


What I envisioned, if only we had room, is an RC circuit connected

through a

zener to the gate of an SCR. The capacitor would charge until it

reached

the threshold of the zener and then switch the SCR on--and it would draw

off

the bit of charge needed to pull the voltage down. A small surface

mount

chip with this set of components or an operational equivalent would help

a

lot.

Mark Folsom



7 posts in the thread and it's still not at all clear what you want.
Way too many "about", 10:1 time interval range, tiny bit of charge...

Just clamp the voltage with a zener.
mike


I think it's pretty clear what I want.
That's often the problem. Customer is SURE he knows what he wants.
But that's usually not what he asks for. It's the old communication
problem. Getting the requirements out is the hardest part of any
project. I called the psychic hotline, but Miss Cleo didn't know either.

If there's something specific you
don't understand, maybe you could ask. Unlike most electronic applications,
this one needs to avoid throwing away the energy that would be lost in
clamping with a zener. I may seem stupid to you, but I already thought of
clamping with a zener.
Nobody said you were stupid, just unspecified.
Here's what you stated:

drawing off a tiny bit of charge will bring the voltage down to half
of its initial value.
If it's really just a tiny bit of charge, why is clamping such a
problem? If you had your magic device, how would that tiny bit of
charge be of benefit??? Stated another way, how are you gonna get the
voltage down without drawing off that tiny bit of charge?

If you think 7 posts is too much, you can stop reading.
I'm trying to be helpful. We're up to 10 posts and there's still
something yet unstated that's driving your requirement.
If you're upset with this, you would have been REALLY upset by
my response to your original vague request. I chose not to send that one.

You're welcome,
mike

Thanks,

Mark Folsom


--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
"mike" <spamme0@juno.com> wrote in message news:3FD67F3A.7070904@juno.com...
Mark Folsom wrote:
"mike" <spamme0@juno.com> wrote in message
news:3FD66A52.7020609@juno.com...

Mark Folsom wrote:

"Dave Platt" <dplatt@radagast.org> wrote in message
news:vtcige6k0q6m4b@corp.supernews.com...


In article <vtchsveg0c4c09@corp.supernews.com>,
Mark Folsom <folsom_snip_man@redshift.com> wrote:



Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is

applied,


like maybe 100 microseconds? If so, what's it called?

Mark Folsom

capacitor.

but I think you meant something more detailed.

A capacitor conducts when voltage is applied, then stops. That's the
opposite of what I asked for.

Correct.

"Inductor" is one possible answer, which might work if you don't need
a particularly "sharp" turn-on, and if you're simply concerned about
passing DC.


For the first 100 to 1000ms of operation, the powered circuit draws

about 5

microamps. The initial voltage, from which we would like to protect
the
powered circuit, could be from 50 to 60 volts. After about 50

microseconds,

drawing off a tiny bit of charge will bring the voltage down to half of

its

initial value, which is acceptable to the powered circuit. Since we

need

this to be tiny, an inductor is unsuitable.



Another approach would be to use a FET, with a suitable gate voltage
being applied through an R/C circuit of some sort... or perhaps using
a bidirectional FET-type optocoupler.


What I envisioned, if only we had room, is an RC circuit connected

through a

zener to the gate of an SCR. The capacitor would charge until it

reached

the threshold of the zener and then switch the SCR on--and it would
draw

off

the bit of charge needed to pull the voltage down. A small surface

mount

chip with this set of components or an operational equivalent would
help

a

lot.

Mark Folsom



7 posts in the thread and it's still not at all clear what you want.
Way too many "about", 10:1 time interval range, tiny bit of charge...

Just clamp the voltage with a zener.
mike


I think it's pretty clear what I want.

That's often the problem. Customer is SURE he knows what he wants.
But that's usually not what he asks for. It's the old communication
problem. Getting the requirements out is the hardest part of any
project. I called the psychic hotline, but Miss Cleo didn't know either.

If there's something specific you
don't understand, maybe you could ask. Unlike most electronic
applications,
this one needs to avoid throwing away the energy that would be lost in
clamping with a zener. I may seem stupid to you, but I already thought
of
clamping with a zener.

Nobody said you were stupid, just unspecified.
Here's what you stated:

drawing off a tiny bit of charge will bring the voltage down to half
of its initial value.

If it's really just a tiny bit of charge, why is clamping such a
problem? If you had your magic device, how would that tiny bit of
charge be of benefit??? Stated another way, how are you gonna get the
voltage down without drawing off that tiny bit of charge?
I have two capacitors that I am charging in series, with a lot of noise, in
about 50 microseconds--then discharging in parallel. I use some diodes to
allow that to happen--I modeled it and then built it and it works and allows
me to get a lot more energy than I do by charging them from the same source
in parallel. The capacitors then power a custom timer ASIC that draws about
5 microamps. At the end of a programable interval that ranges between 100
and 1000 milliseconds, the circuit switches the remaining charge into a 2
ohm resistance. Any device for this function would have to conduct about 8
amps for a few hundred microseconds and have less than a quarter ohm
resistance when in the on condition.

The diodes that we use to switch from series to parallel seem to have enough
capacitance to keep the output up to the charging voltage until a little
charge is drawn off. It appears to take less than two microseconds to go
from 52 volts to 26 volts when the capacitors are loaded with 12kohm on the
output.

The whole purpose of the circuit, up to the ASIC, is to gather some very
scarce energy--clamping with a zener is our default approach, but it reduces
our margins below where we would like them.

Is that clear yet? I'm not going to disclose the whole system design or the
end use.

Mark Folsom
 
"Mark Folsom" <folsom_snip_man@redshift.com> skrev i melding
news:vtc69f4r0v5p44@corp.supernews.com...
Is there a (preferably tiny surface mount) device that starts out
non-conducting and then conducts a short time after a voltage is applied,
like maybe 100 microseconds? If so, what's it called?

Mark Folsom
Something like this:




VCC
.--------.
| |
| |
| >|
| |--------.
.-. /| |
| | | |
| | | |
'-' | |
| | |
o--------o |
| + | |/
### '--------|
--- |>
| |
| |
| |
| |
| |
| |
| |
=== ===
GND GND
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

That's a circuit that short-cuts VCC to GND when the capasitors voltage
reach about 0.7V.
 
RE:
Is that clear yet? I'm not going to disclose the whole system design or
the end use.
Hmmmmm! In your order:
Yes.
I think the end use is somewhat clear.

You seem to have a chip on your shoulder. That's not nice when asking for
help.

Don
 
"Dbowey" <dbowey@aol.com> wrote in message
news:20031210164113.07996.00000531@mb-m16.aol.com...
RE:
Is that clear yet? I'm not going to disclose the whole system design or
the end use.

Hmmmmm! In your order:
Yes.
I think the end use is somewhat clear.

You seem to have a chip on your shoulder. That's not nice when asking for
help.
Well, I was told I should use a capacitor, that I should just clamp the
voltage with a zener, that I should use an inductor, etc., etc. Meanwhile,
I've given more and more detail on how the item would be used, and most of
the comments I get back offer nothing whatever of use--either you haven't
read what I've posted, or you don't understand what I'm trying to do even
after you've read it. Maybe the vast majority of you don't have a clue and
you're just jerking me around for your own amusement. Being nice to a bunch
of ignorant jerks isn't likely to be terribly productive in this context.

Mark Folsom
 
"Mark Folsom" <folsom_snip_man@redshift.com> wrote in message
news:vtf72dobj2jp01@corp.supernews.com...
Well, I was told I should use a capacitor, that I should just clamp the
voltage with a zener, that I should use an inductor, etc., etc.
Meanwhile,
I've given more and more detail on how the item would be used, and most of
the comments I get back offer nothing whatever of use--either you haven't
read what I've posted, or you don't understand what I'm trying to do even
after you've read it. Maybe the vast majority of you don't have a clue
and
you're just jerking me around for your own amusement. Being nice to a
bunch
of ignorant jerks isn't likely to be terribly productive in this context.

I read all the postings closely, and it wasn't until the last one or two
(the one that said you won't disclose more) that I began to have a clue what
you were looking for. That might be because I'm an ignorant jerk. Or it
might be because you're being less successful in your communications than
you had thought. Your initial posting, for instance, gave no hint of
whether you were wanting to switch currents of 100pA or 100kA.

If you ask a question, and some people ask for clarification and others give
answers that aren't what you expected, it is probably because your question
was unclear. Sadly, your perception of how clear it was is not the gating
factor.

If I did indeed understand that recent posting, the bottom line is that you
gather free energy from noise, charge some capacitors, and then eventually
dump most of the juice into a load of about 2 ohms, after waiting a little
while (where the timer is powered from a small fraction of the charge in the
caps). You want to switch about 8A, with an on resistance of < 0.25 ohms,
after a controllable delay. (Gee, sounds like Maxwell's demon.)

I *think* that I understand that the power you want to control is the juice
to the timer; that is, you want to keep the timer out of the picture until
some of the charge has been bled off of the caps. Later posts seem to
suggest that what you're interested in is the switch to the 2 ohm load,
though, which seems to have thrown some folks off the scent. Perhaps I'm
confused. Or, just an ignorant jerk.

If I'm not confused, then I wonder whether perhaps powering the timer off
just one of the caps, rather than off the series combination, might be a
better approach. If not, then another consideration is that since you're
talking very small currents, you might be able to just use a resistor and a
MOSFET; that is, avoid the C, just use the gate charge of the MOSFET as a
capacitor. Only two parts, there.
 
Mark Folsom wrote:
"Dbowey" <dbowey@aol.com> wrote in message
news:20031210164113.07996.00000531@mb-m16.aol.com...

RE:

Is that clear yet? I'm not going to disclose the whole system design or
the end use.

Hmmmmm! In your order:
Yes.
I think the end use is somewhat clear.

You seem to have a chip on your shoulder. That's not nice when asking for
help.


Well, I was told I should use a capacitor, that I should just clamp the
voltage with a zener, that I should use an inductor, etc., etc. Meanwhile,
I've given more and more detail on how the item would be used, and most of
the comments I get back offer nothing whatever of use--either you haven't
read what I've posted, or you don't understand what I'm trying to do even
after you've read it. Maybe the vast majority of you don't have a clue and
you're just jerking me around for your own amusement. Being nice to a bunch
of ignorant jerks isn't likely to be terribly productive in this context.

Mark Folsom
Ok, so I'm playing 20-questions, reverse engineering a secret design to
help someone who's calling me names.
I think that's called masochism.
But I'm bored, and I really am a nice guy (most of the time), so here goes.

Interesting little details the 8 amps and 2 ohms.
Would have been nice to have that information in the beginning.

Let's do a back of the envelope approximation.

If your tiny bit of charge is the 5 uA load that takes your caps from
60V to half that in 50 uS, you have about 8.3 pF of capacitance.
When you discharge that into 2 ohms, you have a time constant of
16.6 picoseconds.
So, you need a deivce that can switch 8 amps and get that 16pS time
constant to last a few hundred microseconds.

I expect that's not what you meant. Can you see why some of us might
be more than a little confused by a descrepancy that's 4 orders of
magnitude?

So, I guess I am an ignorant jerk that just can't understand what you're
trying to do even after I've read it.

If you're gonna hide the details, at least try to have some consistency
in the numbers you do post. My subscription to the psychic hotline
has expired.

Your move,
mike

--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/
 
"Mark Folsom" <folsom_snip_man@redshift.com> wrote:
Well, I was told I should use a capacitor, that I should just clamp the
voltage with a zener, that I should use an inductor, etc., etc. Meanwhile,
I've given more and more detail on how the item would be used, and most of
the comments I get back offer nothing whatever of use--either you haven't
read what I've posted, or you don't understand what I'm trying to do even
after you've read it. Maybe the vast majority of you don't have a clue and
you're just jerking me around for your own amusement. Being nice to a bunch
of ignorant jerks isn't likely to be terribly productive in this context.
Well, if you had given sufficient detail in the first place, you
wouldn't be having this problem. It looks from here like you've been
given a number of ideas which may work, but without a detailed
knowledge of whatit is you are trying to do (which you've said you
won't provide), many of us are just shooting in the dark. The more
detailed your requirements, the more useful will be the [free]
responses you get. In either case, you get what you pay for.

[For instance, if you are looking at the output of a photodiode, maybe
replacing it with a small solar panel would give you enough power to
run your switching circuit...]

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com
 

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