Re: Slew rate and BW logic when designing differentietor of a pulse
john23,
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I uploaded this file:
which is in this group's Temp directory in Files. ?
Run it, then click in the plot window, and press the Spacebar to re-load the plot settings.? It compares the circuit's actual response with the ideal derivative of the input voltage.
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You can see that the circuit fails to approximate the derivative.? The ideal output at V(out) should be the negative of the derivative of V(in), but it does not look like that at all.? So when you wrote that the circuit is "working", all I can say is that it is working extremely poorly.? It lacks the bandwidth needed to approximate the actual derivative of the input pulse.? For the 1 ns rise time, the extreme leading edge of V(out) somewhat follows the derivative of V(in), but it is in the wrong direction!? Then several nanoseconds later it swings down, and then rings.? So it is completely wrong, lacking bandwidth.
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I thought the response might have been coupling via another mechanism, but it is not that.? It is doing the best that it can, with too little bandwidth.? That's all.? Its output voltage wiggles, but wrongly.
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Andy
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The following items have been added to the Files area of the [email protected] group.
By: Andy <ai.egrps@...>
Description:
Examine the response of differentiator circuit that uses AD8034
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I know what you mean and agree it would be better if a non-standard size. On a practical basis, if someone is paying $20-30 for a battery, it is not left on the kitchen table. These batteries typically are strictly inventoried by the companies that buy them.? Military, space, and other critical applications. Bertho ?
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From: [email protected] <[email protected]> On Behalf Of Andy via groups.io
Sent: 4 March, 2025 20:44
To: [email protected]
Subject: Re: [electronics101] Batteries? On Tue, Mar 4, 2025 at 11:24 AM, Bertho wrote: Andy, When that type of performance is needed, it is a custom design project and not for the general public. I do not expect the batteries will be replaced in my lifetime. ...
I get that. But the problem is they are selling them in the AA, C, and D form-factors, where the expected voltage is 1.5 V, not 3.6 V.? That is a catastrophe waiting to happen.
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On Tue, Mar 4, 2025 at 11:24 AM, Bertho wrote:
Andy,
When that type of performance is needed, it is a custom design project and not for the general public.
I do not expect the batteries will be replaced in my lifetime.
...
I get that.
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But the problem is they are selling them in the AA, C, and D form-factors, where the expected voltage is 1.5 V, not 3.6 V.? That is a catastrophe waiting to happen.
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Andy
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Re: Slew rate and BW logic when designing differentietor of a pulse
john23,
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Every time you delete and re-send a message, that is one more message we receive from you.
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So far I have received 6 messages that you've sent in this topic, but only 2 remain.? You can't delete the ones in our email.? I know it can be difficult, but try to get the messages right before sending, so that you don't need to delete and re-send over and over.
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Andy
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Re: Slew rate and BW logic when designing differentietor of a pulse
On Tue, Mar 4, 2025 at 03:39 PM, john23 wrote:
Hello Andy , regarding the 200Ohm load,How did you? see that I am over loading the opamp?
From the datasheet and a few calculations.
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Your simulation uses +/- 7.5 V power.? Let's assume the output can approach (not reach) the rails.? The output pin sees R2 = 200 ohms to a virtual ground.? 7.5 / 200 = 37.5 mA.? The datasheet shows output short-circuit current = 40 mA typical with +/- 5 V supplies.? ?That is not guaranteed.? Figure 37 shows the output saturation voltage, where the output can't source or sink any more current.? It starts limiting around 25 mA, which is less than 37.5 mA, and again that is typical.? Let's say the minimum at clipping is 20 mA, which limits your outputs to only half the supply voltages (clips at +/- 4 V because of the 200 ohm load).
Could you say what measurement needs to be done and where in the datasheet I need to look for this issue to see that I am not ruining the OPAMP?
With the circuit wired as it was simulated, see at what point the output voltage clips.? Again, keep in mind it is typical only; worst-case will be worse than what is measured.
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Andy
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Re: Wireless Camera repair
Good info. Thanks!
On 3/4/2025 4:29 PM, wn4isx via
groups.io wrote:
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Wiki has an interesting page on submiature RF connectors....
I had no idea there were so many connectors that look very
similar.
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_._,_._
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Re: OFF-TOPIC: Jeeps, shifting, and snow (was: Batteries)
Do you still have the Jeep? I restored a 1939 Plymouth Pickup truck and would love to restore a Jeep.
Dan Kahn
Newfoundland PA On Tuesday, March 4, 2025 at 03:39:56 PM EST, wn4isx via groups.io <wn4isx@...> wrote:
On Tue, Mar 4, 2025 at 08:45 AM, Donald H Locker wrote: until I clear out "all that stuff you've got here! In our case it was me who decided "Dear God I've got to downsize!" I had about 30X30X20 in the corner of a warehouse filled with 'stuff.' I even had a WWII era jeep. That was a nightmare to license and transfer. I'm down to a few photocopy boxes of stuff I have to do some serious thinking. It might be worth the effort to sell on Ebay.? I found stuff I had no idea I had or where it came from. ? The university used to have surplus property auctions the 3rd Thursday of most months and I'd visit afte the big boys took what they wanted and pick out some "gold". a brand new Bird termaline watt meter, a perfect Bird throughline VSWR meter, audio oscillators, radiation detectors out the ying yang. All sorts of goodies that I'll never use. ? There is a certain feeling of freedom getting rid of stuff you'll never use. ? ? ? ?
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Re: Wireless Camera repair
Wiki has an interesting page on submiature RF connectors....
I had no idea there were so many connectors that look very similar.
?
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Re: Slew rate and BW logic when designing differentietor of a pulse
Hello Andy , regarding the 200Ohm load,How did you? see that I am over loading the opamp?
Could you say what measurement needs to be done and where in the datasheet I need to look for this issue to see that I am not ruining the OPAMP?
Thanks.
https://www.analog.com/media/en/technical-documentation/data-sheets/ad8033_8034.pdf
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OFF-TOPIC: Jeeps, shifting, and snow (was: Batteries)
On Tue, Mar 4, 2025 at 08:45 AM, Donald H Locker wrote:
until I clear out "all that stuff you've got here!
In our case it was me who decided "Dear God I've got to downsize!"
I had about 30X30X20 in the corner of a warehouse filled with 'stuff.'
I even had a WWII era jeep. That was a nightmare to license and transfer.
I'm down to a few photocopy boxes of stuff I have to do some serious thinking.
It might be worth the effort to sell on Ebay.?
I found stuff I had no idea I had or where it came from.
?
The university used to have surplus property auctions the 3rd Thursday of most months and I'd visit afte the big boys took what they wanted and pick out some "gold". a brand new Bird termaline watt meter, a perfect Bird throughline VSWR meter, audio oscillators, radiation detectors out the ying yang. All sorts of goodies that I'll never use.
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There is a certain feeling of freedom getting rid of stuff you'll never use.
?
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On Tuesday 04 March 2025 09:08:34 am Bertho wrote: For the ultimate lithium battery (cell) see:
The Tadarian battery operating temperature is -80°C to +125°C and 40 year life.
We are using a D-cell in traffic control equipment.
They cost an arm and a leg…. That's one heck of a temperature range, there... And a 40 year lifespan? Wow. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Andy, When that type of performance is needed, it is a custom design project and not for the general public. I do not expect the batteries will be replaced in my lifetime. When the equipment is mounted at a top of a pole and a bucket truck is required for service, and the road lane needs to be closed, the mechanical size/cost is not an significant issue. Regular rechargeable lithiums are also around 3.6V so no surprise. Amazing batteries! Bertho ?
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From: [email protected] <[email protected]> On Behalf Of Andy via groups.io
Sent: 4 March, 2025 10:27
To: [email protected]
Subject: Re: [electronics101] Batteries? On Tue, Mar 4, 2025 at 09:23 AM, Bertho wrote: For the ultimate lithium battery (cell) see:
Darn!? All these alternate technologies!? With built-in ways to mess us up. Those Tadiran cells come in standard AA, C, and D form factors, but do NOT have the standard voltage.? Their nominal voltage in those form factors is 3.6V.? Now that's a million catastrophies just waiting to happen. THIS is the kind of thing that should never have happened.? Shame on them. Hopefully their very high cost will deter most people from using them in equipment designed to accept AA, C, or D dry cells. I also wonder why anyone would design equipment to accept 3.6V cells with AA, C, or D form factors.? Do traffic control equipment designers really do such a thing?? Or do they take the smart route and only use the alternate form factors?
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Re: IR digital cameras (was: Batteries)
Some Panasonic digital cameras are fairly easy to modify.
You remove the IR blocking filter from the CCD camera.
With this mod you'll get a mix of visible light and IR, I still had the IR passive lens from my childhood, I hang on to almost everything, spent the last 6 months getting rid of stuff.
Anyway there are two different IR passive filters, one is very deep red, the other appears black.
To use the "black" one requires the camera to be locked down on a tripod, you focus with the deep red, then change to the "black" filter and take your photo. Back then we used 100W incandescent bulbs on each side at roughly 45 degree angles.
Today you can see what the camera is seeing on the LCD screen, a heck of a lot easier.
I built an LED IR illuminator and I can mount the array using the quarter inch tripod mount.
I've built a 'gun' frame the camera is mounted on and the LED array is above the camera.
Looks like something from a cheap SF movie but it works pretty well.
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The built in xenon strobe produces very little IR. It's no big deal because I simply turn the flash off.
I have an IR blocking filter so I can mount it on the camera and use it for visible light but my wife has a ice Kodak digital camera we use for visible light and the camera on my cell phone is surprisingly good. It is 12 megapixals.
The big weakness with cell phone cameras isn't the CCD camera but the lens. Real cameras have sophisticated lens, multiple lens, each with a special diachromatic coating to reduce lens flare etc.
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My cell phone has a higher bit count then the Sony broadcast cameras we used at my last job.
Of course the lens for those cameras cost about 100k each.?
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I have the image intensifier lens from a 3nd generation night vision scope. it's an odd shape and I probably need to learn to print a plastic case. I'd love to interface a TV or still camera to the intensifier but optics gets complicated and really tricky.
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I have the output lens from a WWII sniper scope that used a "car" headlight with a gel IR filter to illuminate the scene. I had the entire sniper scope but the image converter tube went gassy after a decade or so.
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I need to come up with a lens to feed the image to the intensifier tube. This is probably a "I'd really like to make this work but I don't know enough." project. The tube is a reject because it has one more pixel defect then the specs allow.
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Given US regulations on such "high tech" stuff I can't go into any real details. Which is silly because a friend has a late model Russian night scope so clearly the secret is out there.
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""On the same note, it is a violation of ITAR to allow any non-U.S. citizen to look through U.S. Gen3 night vision equipment (even on US Soil). They are also not allowed to have access to any operator’s manuals or documentation, whatsoever, pertaining to US Gen 3 Night Vision Devices. This is a little-known fact about ITAR and Night Vision Devices, but it is true. We have confirmed this with the US State Department and major Night Vision Manufacturers. At TNVC, we take great care to ensure our clients are properly informed on laws and regulations pertaining to night vision. ""
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Re: Slew rate and BW logic when designing differentietor of a pulse
On Tue, Mar 4, 2025 at 06:50 AM, Michael Dunn wrote:
I think we're probably just seeing the op-amp's overdrive recovery behaviour.?
Agreed.
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Be aware that you are also over-stressing the op-amp with the 200 ohm load.? That's 37.5 mA peak output, which it might not provide.? But I think that is unrelated to the question.
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Andy
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IR digital cameras (was: Batteries)
On Tue, Mar 4, 2025 at 08:37 AM, wn4isx wrote:
Normal digital cameras are moderately sensitive to IR, ...
I wonder if that's true of all of them.? It probably is.? Photons are photons.? I know my first digital almost-SLR from 20+ years ago could, and I considered having the modification done to it.? I love IR photography, but never experimented with it.? I'm afraid it might become a "fad" that loses its appeal after a few hundred IR photos.
The camera has a xenon flash that produces near zero IR. I have to illuminate an object with an array of IR LEDs.
Can't you just use the built-in flash?
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Or did the camera's modification add an IR-only filter to the lens, making it insensitive to visible light?
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Andy
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On Tue, Mar 4, 2025 at 09:23 AM, Bertho wrote:
For the ultimate lithium battery (cell) see:
Darn!? All these alternate technologies!? With built-in ways to mess us up.
?
Those Tadiran cells come in standard AA, C, and D form factors, but do NOT have the standard voltage.? Their nominal voltage in those form factors is 3.6V.? Now that's a million catastrophies just waiting to happen.
?
THIS is the kind of thing that should never have happened.? Shame on them.
?
Hopefully their very high cost will deter most people from using them in equipment designed to accept AA, C, or D dry cells.
?
I also wonder why anyone would design equipment to accept 3.6V cells with AA, C, or D form factors.? Do traffic control equipment designers really do such a thing?? Or do they take the smart route and only use the alternate form factors?
?
Andy
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For the ultimate lithium battery (cell) see:
? The Tadarian battery operating temperature is -80°C to +125°C and 40 year life. We are using a D-cell in traffic control equipment. They cost an arm and a leg…. Bertho
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Well, that is far more response than I expected! Many thanks. (My
spouse won't let me bring any more technology bits into the house
until I clear out "all that stuff you've got here!")
Donald.
On 3/4/25 08:37, wn4isx via groups.io
wrote:
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I've ordered a set of 4 AA cells to see how they work.
Now these cells clearly have a circuit for charging and to
step the 3.6ishV down to 1.5V.
IF they perform as advertised, they would be an extremely
good value. I'll run some tests, voltage drop in a 4 cell
incandescent flashlight versus time, charge them, leave them in
the freezer and repeat the test. We seldom have temperatures
below zero more often then once or twice a winter, but when we
do, many cells / batteries roll over and play dead until they
warm up.
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I have an older Panasonic digital camera that eats cells, it
takes two AAs and you get about 50 photos with high quality
alkaline. It will be interesting to see how these cells work in
this camera.?
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I only keep the camera because we were able to remove the IR
blocking filter and the camera takes very high quality IR
photos. I fell in love with IR when I was 8 and Dad bought a
roll of Kodak IR film to photograph some trees on land our
family owns in Eastern KY. Trees with health problems can
"scream" at you in IR (or BW with a deep red filter).
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We ended up cutting down about 50 diseased trees. I was too
young to understand what was wrong.
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Normal digital cameras are moderately sensitive to IR, you
can check an IR remote control with a camera phone, but they
include IR blocking filters that knock down at least 90% of the
near IR and all of the deeper IR, remove the filter and it's an
entire new world, if you have an IR pass filter.
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The camera has a xenon flash that produces near zero IR. I
have to illuminate an object with an array of IR LEDs.
?
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I've ordered a set of 4 AA cells to see how they work.
Now these cells clearly have a circuit for charging and to step the 3.6ishV down to 1.5V.
IF they perform as advertised, they would be an extremely good value. I'll run some tests, voltage drop in a 4 cell incandescent flashlight versus time, charge them, leave them in the freezer and repeat the test. We seldom have temperatures below zero more often then once or twice a winter, but when we do, many cells / batteries roll over and play dead until they warm up.
?
I have an older Panasonic digital camera that eats cells, it takes two AAs and you get about 50 photos with high quality alkaline. It will be interesting to see how these cells work in this camera.?
?
I only keep the camera because we were able to remove the IR blocking filter and the camera takes very high quality IR photos. I fell in love with IR when I was 8 and Dad bought a roll of Kodak IR film to photograph some trees on land our family owns in Eastern KY. Trees with health problems can "scream" at you in IR (or BW with a deep red filter).
?
We ended up cutting down about 50 diseased trees. I was too young to understand what was wrong.
?
Normal digital cameras are moderately sensitive to IR, you can check an IR remote control with a camera phone, but they include IR blocking filters that knock down at least 90% of the near IR and all of the deeper IR, remove the filter and it's an entire new world, if you have an IR pass filter.
?
The camera has a xenon flash that produces near zero IR. I have to illuminate an object with an array of IR LEDs.
?
?
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?
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Bertho