Searching \ for '[EE]: Rocket Project' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=rocket+project
Search entire site for: 'Rocket Project'.

Exact match. Not showing close matches.
PICList Thread
'[EE]: Rocket Project'
2000\06\29@002139 by Sean Breheny

face picon face
Hi all,

Just a quick update on the progress of the rocket project recently
discussed here under the heading: "Noise in phototransistors".

First off, I made a new circuit which has a couple of amplification stages
and a 4-pole butterworth high pass filter (to eliminate 60/120 Hz light
sources while passing the ~2.5kHz carrier properly). Using a PNZ330CL PIN
photodiode, my tests show that the noise delivered by this circuit is close
to the best it can be (on the order of 50 pA in the photodiode, while shot
noise from the current caused by ambient light would cause about 25 pA in
the roughly 1kHz BW which it currently has). I am also using a 37 mm lens
now and it has greatly improved the sensitivity, thanks! The source is
easily detectible in a 1kHz BW in headphones at >100 feet (I didn't test
further) and with the addition of the narrow digital band pass filter in
the PIC, the noise should be decreased by about a factor of 5 or so (final
BW will ony be about 20Hz).

I found out that a large percentage of my noise I was seeing before was due
to 60Hz (and harmonics) pickup at several high-impedance points in the
circuit. I reduced the resistor values and increased the corresponding
capacitor values (these points were in the filters).

The phototransistor does seem to have several times the noise level of the
photodiode, too.

I have also ordered some IR transparent, visible light blocking plastic to
reduce the effects of ambient light on the sensor (hoping to reduce DC
current in photodiode). Currently, taking it outside on a bright sunny day
saturates the first stage, so I may have to reduce the transimpedance gain
if the plastic doesn't do the trick.

I also made a matlab-based simulation including ballistic and aerodynamic
effects, and a simple control scheme. It appears from this simulation that
my servos will be plenty fast, given that I have a non-moving target and
will only have about a +/- 15 deg FOV anyway.

One last thing: Dave or anyone else, where can I find out if this really is
disallowed (for sure) under NAR rules(Honestly, I am not trying to hit the
target, only use an air-suspended device to guide a model rocket near to
it, and I plan on adjusting the null zone and control authority to try to
prevent a direct hit)? I was planning on testing this out at a local RC
flying field, but I just realized that the Sportflyer's (I think that's the
group he's with) rules may not allow this if it doesn't comply with the
NAR(like the AMA), and I don't want to cause insurance problems. (He was
kind enough to say I could launch rockets there, but this might be pushing
it ;-)

Once again, standard disclaimer, if you are wondering what this is about,
read the previous thread, it is a simple model rocketry project to guide a
model rocket near some balloons, it is NOT an anti-aircraft missile. (I
always append this lest someone read one of these messages in the archives).

|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
\--------------=----------------
Save lives, please look at http://www.all.org
Personal page: http://www.people.cornell.edu/pages/shb7
spam_OUTshb7TakeThisOuTspamcornell.edu ICQ #: 3329174

____________NetZero Free Internet Access and Email_________
Download Now     http://www.netzero.net/download/index.html
Request a CDROM  1-800-333-3633
___________________________________________________________

2000\06\29@055252 by Andrew Seddon

picon face
Hi.
   Could you tell me where you got that visible light blocking plastic that
lets IR thorugh from please? That could come in usefull in what I am about
to do.

Cheers..

Andrew Seddon

2000\06\29@113758 by H.P. de Vries

flavicon
face
Hi all.

I recently designed a robot for a contest in France.
(http://eurobot.win.tue.nl)
The robot found it's
way by means of Infra-red beacons. As the match was filmed on TV, I had to
design something that was immune for ambient light influences. The result
was, that the modulated signal (1 - 5 KHz) was clearly measurable, even when
a 500-W halogen lamp was pointed at the IR-receivers at a distance of .5
metres. The circuit used for detection consists of a couple of transistors
and capacitors to simulate an inductance.
If someone has interest, I could send a pdf of the schematic. As far as the
plastic concerns :
Farnell (http://www.farnell.com) had IR-lenses from that type of plastic. Though I
have to say the solution I used works better than those lenses.

Cya.

Hans

On Thu, Jun 29, 2000 at 10:47:35AM +0100, Andrew Seddon wrote:
> Hi.
>     Could you tell me where you got that visible light blocking plastic that
> lets IR thorugh from please? That could come in usefull in what I am about
> to do.
>
> Cheers..
>
> Andrew Seddon
>

2000\06\29@125837 by Lawrence Lile

flavicon
face
Two ways -

The cheapest IR filter is a fiece of exposed 35mm film.  Just get one of the
negatives from those "scenic lens caps" that people always take, and tell
your photo lab to develop it anyway.  Or just ask them for one- they thrown
them away.

The next level is an actual IR filter from a good phot shop.  These screw
onto a regular camera lens, and are used for taking IR pictures with special
film and a standard camera.  They look coal black, but are IR clear.  ~ $25.

-----Original Message-----
From: Andrew Seddon <.....seddonaKILLspamspam@spam@HOTMAIL.COM>
To: PICLISTspamKILLspamMITVMA.MIT.EDU <.....PICLISTKILLspamspam.....MITVMA.MIT.EDU>
Date: Thursday, June 29, 2000 4:53 AM
Subject: [EE]: Rocket Project


>Hi.
>    Could you tell me where you got that visible light blocking plastic
that
>lets IR thorugh from please? That could come in usefull in what I am about
>to do.
>
>Cheers..
>
>Andrew Seddon

2000\06\29@131330 by Robert A. LaBudde

flavicon
face
At 10:47 AM 6/29/00 +0100, Andrew wrote:
>Hi.
>     Could you tell me where you got that visible light blocking plastic that
>lets IR thorugh from please? That could come in usefull in what I am about
>to do.

Exposed (fogged) photographic film is the standard IR filter. Just point
the camera at the sky to over expose it. Than use a piece of the developed
negative to block visible light and pass IR.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: EraseMEralspam_OUTspamTakeThisOuTlcfltd.com
Least Cost Formulations, Ltd.                   URL: http://lcfltd.com/
824 Timberlake Drive                            Tel: 757-467-0954
Virginia Beach, VA 23464-3239                   Fax: 757-467-2947

"Vere scire est per causas scire"
================================================================

2000\06\29@133043 by David VanHorn

flavicon
face
>
>The next level is an actual IR filter from a good phot shop.  These screw
>onto a regular camera lens, and are used for taking IR pictures with special
>film and a standard camera.  They look coal black, but are IR clear.  ~ $25.

Many "black" plastics are almost transparent to IR. (ask me how I know...)
You can build a simple densitometer from an IRLED, phototransistor (the
kind with it's own filter) and an op-amp.
Set the circuit such that the opamp varies the LED current to get a fixed
photocurrent from the transistor, then measure the IRLED current for a
relative indication of density.

--

http://www.SpamWhack.com  A pre-emptive strike against spam
A tornado is a lady whose skirts you do NOT want to look up!
Where's dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9

2000\06\29@175708 by Des Bromilow

flavicon
face
Sean,

I'm not an expert wit  modle rockets, but the QRA has NO religious guidleine on active control, however in Australia the "wise word" for us was "No active control during the thrust phase", control during coasting, or recovery is acceptable.

Apparently this guideline is based on the instructions from the Estes Astroblaster, Sweet vee, and the other RC BG.
Maybe you should get the guidlelines/regs for RC BG/RG and see what they say... I really think this will be the closest you're going to find about guidance under thrust.

Hope this helps,
Des Bromilow
Fulltime Engineer, Part time fixer-upper, Rocket builder, QRA President, and general dogsbody.

>>> Sean Breheny <shb7spamspam_OUTCORNELL.EDU> 6/29/00 2:13:32 pm >>>
Hi all,

Just a quick update on the progress of the rocket project recently
discussed here under the heading: "Noise in phototransistors".

First off, I made a new circuit which has a couple of amplification stages
and a 4-pole butterworth high pass filter (to eliminate 60/120 Hz light
sources while passing the ~2.5kHz carrier properly). Using a PNZ330CL PIN
photodiode, my tests show that the noise delivered by this circuit is close
to the best it can be (on the order of 50 pA in the photodiode, while shot
noise from the current caused by ambient light would cause about 25 pA in
the roughly 1kHz BW which it currently has). I am also using a 37 mm lens
now and it has greatly improved the sensitivity, thanks! The source is
easily detectible in a 1kHz BW in headphones at >100 feet (I didn't test
further) and with the addition of the narrow digital band pass filter in
the PIC, the noise should be decreased by about a factor of 5 or so (final
BW will ony be about 20Hz).

I found out that a large percentage of my noise I was seeing before was due
to 60Hz (and harmonics) pickup at several high-impedance points in the
circuit. I reduced the resistor values and increased the corresponding
capacitor values (these points were in the filters).

The phototransistor does seem to have several times the noise level of the
photodiode, too.

I have also ordered some IR transparent, visible light blocking plastic to
reduce the effects of ambient light on the sensor (hoping to reduce DC
current in photodiode). Currently, taking it outside on a bright sunny day
saturates the first stage, so I may have to reduce the transimpedance gain
if the plastic doesn't do the trick.

I also made a matlab-based simulation including ballistic and aerodynamic
effects, and a simple control scheme. It appears from this simulation that
my servos will be plenty fast, given that I have a non-moving target and
will only have about a +/- 15 deg FOV anyway.

One last thing: Dave or anyone else, where can I find out if this really is
disallowed (for sure) under NAR rules(Honestly, I am not trying to hit the
target, only use an air-suspended device to guide a model rocket near to
it, and I plan on adjusting the null zone and control authority to try to
prevent a direct hit)? I was planning on testing this out at a local RC
flying field, but I just realized that the Sportflyer's (I think that's the
group he's with) rules may not allow this if it doesn't comply with the
NAR(like the AMA), and I don't want to cause insurance problems. (He was
kind enough to say I could launch rockets there, but this might be pushing
it ;-)

Once again, standard disclaimer, if you are wondering what this is about,
read the previous thread, it is a simple model rocketry project to guide a
model rocket near some balloons, it is NOT an anti-aircraft missile. (I
always append this lest someone read one of these messages in the archives).

|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
\--------------=----------------
Save lives, please look at http://www.all.org Personal page: http://www.people.cornell.edu/pages/shb7 @spam@shb7KILLspamspamcornell.edu ICQ #: 3329174

____________NetZero Free Internet Access and Email_________
Download Now     http://www.netzero.net/download/index.html Request a CDROM  1-800-333-3633
___________________________________________________________

2000\06\29@220510 by Damon Hopkins
flavicon
face
"Robert A. LaBudde" wrote:
>
> At 10:47 AM 6/29/00 +0100, Andrew wrote:
> >Hi.
> >     Could you tell me where you got that visible light blocking plastic that
> >lets IR thorugh from please? That could come in usefull in what I am about
> >to do.
>
> Exposed (fogged) photographic film is the standard IR filter. Just point
> the camera at the sky to over expose it. Than use a piece of the developed
> negative to block visible light and pass IR.
>
> ================================================================
> Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: KILLspamralKILLspamspamlcfltd.com
> Least Cost Formulations, Ltd.                   URL: http://lcfltd.com/
> 824 Timberlake Drive                            Tel: 757-467-0954
> Virginia Beach, VA 23464-3239                   Fax: 757-467-2947
>
> "Vere scire est per causas scire"
> ================================================================

or just yank the film out of the roll.. in the daylight.. and then wind
it back up by hand.. that way you don't get the frame marks every 35mm
just one blank roll.. get some CHEAP film.. like a 10-12shot of 100
speed film for like 99 cents. make sure you tell the film shop it's
supposed to be that way and to not cut the negatives and don't bother to
print it..

at a Ritz Camera or Wolf around here it's only like $3 to get the
negatives developed..

2000\06\29@221546 by Dale Botkin

flavicon
face
> > Exposed (fogged) photographic film is the standard IR filter. Just point
> > the camera at the sky to over expose it. Than use a piece of
> the developed
> > negative to block visible light and pass IR.

Does B&W film work for this as well as color?

Dale

2000\06\30@035337 by Alan B. Pearce

face picon face
>or just yank the film out of the roll.. in the daylight.. and then wind
>it back up by hand.. that way you don't get the frame marks every 35mm
>just one blank roll.. get some CHEAP film.. like a 10-12shot of 100
>speed film for like 99 cents. make sure you tell the film shop it's
>supposed to be that way and to not cut the negatives and don't bother to
>print it..

just ask at the shop and they may have someones "mistake" they are about to
throw out.

2000\06\30@073328 by Andrew Kunz

flavicon
face
B&W or color?

Andy









Damon Hopkins <RemoveMEmdhopkinTakeThisOuTspamUNITY.NCSU.EDU> on 06/30/2000 02:03:28 AM

Please respond to pic microcontroller discussion list <spamBeGonePICLISTspamBeGonespamMITVMA.MIT.EDU>








To:      TakeThisOuTPICLISTEraseMEspamspam_OUTMITVMA.MIT.EDU

cc:      (bcc: Andrew Kunz/TDI_NOTES)



Subject: Re: [EE]: Rocket Project








"Robert A. LaBudde" wrote:
{Quote hidden}

or just yank the film out of the roll.. in the daylight.. and then wind
it back up by hand.. that way you don't get the frame marks every 35mm
just one blank roll.. get some CHEAP film.. like a 10-12shot of 100
speed film for like 99 cents. make sure you tell the film shop it's
supposed to be that way and to not cut the negatives and don't bother to
print it..

at a Ritz Camera or Wolf around here it's only like $3 to get the
negatives developed..


'[EE]: Rocket Project'
2000\07\01@014636 by Damon Hopkins
flavicon
face
Andrew Kunz wrote:
>
> B&W or color?
You know .. it's funny that for as much as I know about film I have no
idea..
I took for granted what the other poster said about just using exposed
film.. I'd guess color as color film has separate layers w/ dyes in it
that are reactive to different spectrums of light (cyan,magenta,yellow)
also it's cheaper to develop as most film labs can process it in house..
I'd suggest lower speed film as it contains finer particles of silver
(bigger particles would mean more light blockage i.e. most sensitive to
light in regular usage) it's also cheaper.
I'll pass this by my father who knows just about everything.. he used to
make his own photo chemicals and paper when my mother was a
photographer.. he'll probably know..

               Damon Hopkins
--
/-=-=-=-=-=-=-=-=-=-=-=-=-\
| http://www.openpic.com  |
| New OpenSource Pic site |
\-=-=-=-=-=-=-=-==-=-==-=-/

2000\07\01@035034 by Lee Jones

flavicon
face
>>> exposed film as IR filter

>> B&W or color?

> I took for granted what the other poster said about just using
> exposed film.. I'd guess color as color film has separate layers
> w/ dyes in it that are reactive to different spectrums of light
> (cyan,magenta,yellow)

I believe you want exposed & developed color negative film
or unexposed & developer color reversal film (i.e. slide film).
Color negative film will have an orange tint.  Slide film will
have a black look.

Checking a Kodak data book on color films, the cyan layer's
spectral response curve falls off at 700nm.  IR at 800nm or
so should pass quite well.

Black & white isn't as easy a question as expected.  There's
the old style films, like Kodak Tri-X, based on silver granules.
Those, when exposed and developed, should have a fairly flat
spectral response curve.  I would expect they would attenuate
IR wavelengths as well as visible light.

There are also black & white emulsions based on color film
technology, such as Kodak's T-Max.  I have no idea how they
would respond as an IR filter.

                                               Lee Jones

2000\07\01@122411 by Robert A. LaBudde

flavicon
face
At 01:49 AM 7/1/00 -0400, Damon wrote:
>Andrew Kunz wrote:
> >
> > B&W or color?
>You know .. it's funny that for as much as I know about film I have no
>idea..
>I took for granted what the other poster said about just using exposed
>film.. I'd guess color as color film has separate layers w/ dyes in it
>that are reactive to different spectrums of light (cyan,magenta,yellow)
>also it's cheaper to develop as most film labs can process it in house..
>I'd suggest lower speed film as it contains finer particles of silver
>(bigger particles would mean more light blockage i.e. most sensitive to
>light in regular usage) it's also cheaper.
>I'll pass this by my father who knows just about everything.. he used to
>make his own photo chemicals and paper when my mother was a
>photographer.. he'll probably know..

Black and white is much more predictable.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ralEraseMEspam.....lcfltd.com
Least Cost Formulations, Ltd.                   URL: http://lcfltd.com/
824 Timberlake Drive                            Tel: 757-467-0954
Virginia Beach, VA 23464-3239                   Fax: 757-467-2947

"Vere scire est per causas scire"
================================================================

2000\07\03@000958 by Damon Hopkins

flavicon
face
Andrew Kunz wrote:
{Quote hidden}

I talked to my dad. he works at Honeywell and ALOT of what they do is
with IR stuff.. he said what they use is called polysulfone from GE. I
believe he said get some Udel P-1700 and tell them you want it to block
visible light but not IR.. it should be dark purple and he said he
believed you could get a sample of it. it blocks about 90% of visible
light and lets about 90% of the IR spectrum through.

also he said that color any film will just end up being a neutral filter
and block out infrared as well as visible.


                       Damon Hopkins

--
/-=-=-=-=-=-=-=-=-=-=-=-=-\
| http://www.openpic.com  |
| New OpenSource Pic site |
\-=-=-=-=-=-=-=-==-=-==-=-/

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@123301 by Sean Breheny

face picon face
Hi all,

Sorry it took me so long to respond to the original question. The IR
blocking plastic I got was from Edmund Scientific's Industrial Optics
division, part number K43-949 (for a 2" diameter disc). It is  available in
various sizes but is expensize, $7.00 for the 2" disc. It also didn't do
the trick in my case, apparently because there is so much IR in daylight
anyway.

Sean



|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
\--------------=----------------
Save lives, please look at http://www.all.org
Personal page: http://www.people.cornell.edu/pages/shb7
EraseMEshb7spamspamspamBeGonecornell.edu ICQ #: 3329174

____________NetZero Free Internet Access and Email_________
Download Now     http://www.netzero.net/download/index.html
Request a CDROM  1-800-333-3633
___________________________________________________________

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

2000\07\03@123516 by Sean Breheny

face picon face
Dear Hans,

I would be interested in the PDF of that schematic.

Thanks,

Sean

At 05:37 PM 6/29/00 +0200, H.P. de Vries wrote:
{Quote hidden}

that
>> lets IR thorugh from please? That could come in usefull in what I am about
>> to do.
>>
>> Cheers..
>>
>> Andrew Seddon
>>
>
|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
\--------------=----------------
Save lives, please look at http://www.all.org
Personal page: http://www.people.cornell.edu/pages/shb7
RemoveMEshb7KILLspamspamcornell.edu ICQ #: 3329174

____________NetZero Free Internet Access and Email_________
Download Now     http://www.netzero.net/download/index.html
Request a CDROM  1-800-333-3633
___________________________________________________________

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


'[EE]: Rocket Project'
2000\09\01@190932 by Andy Howard
picon face
Sean (and other rocketeering PICsters) might be interested in this model
rocket project:


http://www.circuitcellar.com/pastissues/articles/Consi-98/article.htm


Cheers,

Andy.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

More... (looser matching)
- Last day of these posts
- In 2000 , 2001 only
- Today
- New search...