From cd930 at centrum.cz Thu Nov 1 04:12:30 2007 From: cd930 at centrum.cz (CD930) Date: Thu, 1 Nov 2007 05:12:30 +0100 Subject: [Ronja] FSO 56km Message-ID: <000601c81c3d$6ba3aa50$0101a8c0@Martindoma> http://www.youtube.com/watch?v=u8pN9Tgkxog :-))) ------------- dal?? ??st --------------- HTML p??loha byla odstran?na... URL: http://pointless.net/pipermail/ronja/attachments/20071101/ce7aae2d/attachment.html From clock at twibright.com Thu Nov 1 08:18:16 2007 From: clock at twibright.com (Karel Kulhavy) Date: Thu, 1 Nov 2007 09:18:16 +0100 Subject: [Ronja] A few questions In-Reply-To: <1193874402.6462.2.camel@Apollo> References: <1193763732.6197.21.camel@Apollo> <20071030195341.GA10069@kestrel.barix.local> <1193777861.6197.29.camel@Apollo> <20071031085053.GA14676@kestrel.barix.local> <1193874402.6462.2.camel@Apollo> Message-ID: <20071101081816.GA18945@kestrel.barix.local> On Wed, Oct 31, 2007 at 11:46:42PM +0000, Alec Wright wrote: > On Wed, 2007-10-31 at 09:50 +0100, Karel Kulhavy wrote: > > No the current Ronja design is not suitable for this type of LED. > Are any other LEDs at all acceptable then? Or can it only be the Yes a lot they are listed on the page with the partlist. http://ronja.twibright.com/transmitter/material.php CL< > specified one? I don't mind putting a few transistors in for the higher > power consumption, or changing the lens for the different viewing angle. > > Cheers > Alec Wright > > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja From mark.robinson at paradise.net.nz Thu Nov 8 13:11:09 2007 From: mark.robinson at paradise.net.nz (Mark Robinson) Date: Fri, 09 Nov 2007 02:11:09 +1300 Subject: [Ronja] 10mbps 1,500,000km simulated DX Message-ID: <47330AED.8060308@paradise.net.nz> hi everyone, This article may be interesting: > http://www.oerlikon.com/ecomaXL/index.php?site=SPACE_EN_press_releases_detail&udtx_id=5060 Tenerife, 7. November 2007 - On the Canary Islands last week, a team from Oerlikon Space demonstrated the feasibility of a laser link across a distance of 1.5 million kilometres for the first time ever. In the future, laser links like this one will be able to transmit data across huge distances through the universe far more rapidly and efficiently than is possible using conventional radio links today. To prove that data transmission across the vast distance of 1.5 million kilometres is really feasible, the Oerlikon engineers had devised a special experiment in which they set up a laser link between the islands of La Palma and Tenerife. The transmission unit was modified in such a way that the conditions on the 144-kilometre stretch between the islands exactly reflected those that would prevail on a 1.5 million kilometre link through space. This was achieved primarily by reducing the emission aperture of the laser to a diameter of less than half a millimetre in order to weaken the light signal. ... see also http://science.slashdot.org/article.pl?sid=07/11/07/1559251&threshold=-1 -- all the best Mark 09 Nov 1885 Volunteer forces make landings at Tamaki and St Helliers as part of manoeuvres for an expected invasion by Russia. From clock2 at centrum.cz Sun Nov 11 14:38:03 2007 From: clock2 at centrum.cz (Karel Kulhavy) Date: Sun, 11 Nov 2007 15:38:03 +0100 Subject: [Ronja] e-mail of Ronja author In-Reply-To: <200711091813.22759@centrum.cz> References: <200711091813.22759@centrum.cz> Message-ID: <200711111538.21600@centrum.cz> Hi I have disabled my clock na twibright.com address because of the amount of spam that got through even through a filter and problems configuring SMTP which is now crippled will all those anti-spam rules. I have changed the contact on the Ronja page to display IRC as a primary support channel and made a webmail account just to be able to respond to the Ronja mailing list. I hope with IRC people will be able to get a reply quicker and in less time, because I am often on the IRC. CL< From gmaxwell at gmail.com Sun Nov 18 20:59:40 2007 From: gmaxwell at gmail.com (Gregory Maxwell) Date: Sun, 18 Nov 2007 15:59:40 -0500 Subject: [Ronja] 100Mbit over LEDs Message-ID: How much thought has been given to the possibility of achieving 100mbit using LEDs? In many countries laser emitters are subject to much more regulation than other visible light sources. For example, in the United States any laser with more than 5mw output is at risk of complications from regulations, even if the aperture is so large that only a tiny amount of light could enter the eye. Non-laser sources are not subject to the same scrutiny. Also, for a given output power non-laser sources are much cheaper (red-orange Luxeon 3W outputs >50mw of light and costs $10 .. I'm not aware of any laser diode with price performance near that) Many years ago I measured the bandwidths of some leds that I had and found that they had a decent response to about 20MHz. I do not know what the ronja hardware delivers, but I would assume that it is around that, since about that much is required for 10mbit performance. This is not anywhere near enough bandwidth to do 100mbit using the binary NRZ encoding that ronja uses. It is also not enough to do 100mbit using the three level encoding used on 100TX (which needs about 35MHz). It should, however, be possible to encode 100mbit into that bandpass by using more levels of amplitude modulation. Using multi-level amplitude modulation will require better signal to noise ratios and good driver and photo-cell linearity. I would not expect SNR to be a problem for ronja, but the use of multi-level encoding would add a lot of complexity to the electronics. Has this line of thinking been explored already? From bms at incunabulum.net Sun Nov 18 21:16:42 2007 From: bms at incunabulum.net (Bruce M Simpson) Date: Sun, 18 Nov 2007 21:16:42 +0000 Subject: [Ronja] 100Mbit over LEDs In-Reply-To: References: Message-ID: <4740ABBA.5040004@incunabulum.net> Gregory Maxwell wrote: > Many years ago I measured the bandwidths of some leds that I had and > found that they had a decent response to about 20MHz. I do not know > what the ronja hardware delivers, but I would assume that it is around > that, since about that much is required for 10mbit performance. This > is not anywhere near enough bandwidth to do 100mbit using the binary > NRZ encoding that ronja uses. It is also not enough to do 100mbit > using the three level encoding used on 100TX (which needs about > 35MHz). Quite aside from NRZ, surely the 4B5B encoding used by 100BaseTX can readily be converted to light? or am I missing something? http://en.wikipedia.org/wiki/4B5B regards BMS From gullik.webjorn at flysta.net Mon Nov 19 00:09:23 2007 From: gullik.webjorn at flysta.net (=?us-ascii?Q?Gullik_Webjorn?=) Date: Mon, 19 Nov 2007 01:09:23 +0100 Subject: [Ronja] 100Mbit over LEDs In-Reply-To: Message-ID: >How much thought has been given to the possibility of achieving >100mbit using LEDs? The HPWT (and other) leds can be persuaded to signal att 100 Mbps, just using "brute force driving". However, an equalised led suffers from a much lower level, so distances possible are greatly reduced. Multi level encoding is the way to go I think, encoding is easy, decoding involves linearity and AGC, so rx will be more complicated. Gullik From renobunsoy at yahoo.com Thu Nov 22 15:51:28 2007 From: renobunsoy at yahoo.com (Reno Bunsoy) Date: Thu, 22 Nov 2007 07:51:28 -0800 (PST) Subject: [Ronja] RONJA newbie here, please help Message-ID: <169948.64327.qm@web52006.mail.re2.yahoo.com> Sir/Ma'am Good day! My group and I are working on RONJA Tetrapolis. I have noticed that some electronic components are not available in the Philippine market. Those components are enumerated below. 74HC164 74HC4040 74HC93 74HCT14 CM322522 33uH/0.32A/0.25ohm (COIL) 100uH/0.32A/0.6ohm (COIL) 16MHz crystal oscillator DS26LS31 DS26LS32 LM2671M-5.0 5uF/16 SK36 eledis_1A21-NF1PCAE BAT46 BF908 BPW43 NE592 HPWT-BD00-F4000 As for the resistor with 0.6W we've used a 1W resistor. We've tried the equivalent components listed at your site but still we can't find the said components. Are there any other substitute that we can use? If not, the that leaves us in ordering the components at your site. How long do you think will it take us to receive the components? Kindly send us the details on shipping. Thanks and God Bless. All that is gold does not glitter, Not all those who wander are lost; The old that is strong does not wither, Deep roots are not reached by the frost. >From the ashes a fire shall be woken, A light from the shadows shall spring; Renewed shall be blade that was broken, The crownless again shall be king. ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20071122/263ebadc/attachment.html From arunk at speedpost.net Sat Nov 24 03:12:40 2007 From: arunk at speedpost.net (Arun Krishnan) Date: Sat, 24 Nov 2007 08:42:40 +0530 Subject: [Ronja] RONJA newbie here, please help In-Reply-To: <169948.64327.qm@web52006.mail.re2.yahoo.com> References: <169948.64327.qm@web52006.mail.re2.yahoo.com> Message-ID: <1195873960.25924.1222958359@webmail.messagingengine.com> Hi there, The items you've listed are critical items with no other direct substitutes other than the ones on the RONJA site. Also, the designer of RONJA doesn't sell these things - he just has documentation up on his site. I'd suggest buying these things from an online retailer (like RS, which has a local site for Philipines : http://www.rs-components.com/index.html ) who sends internationally - do remember that their prices are highly inflated . But there is no real other choice. Do remember that RS may not have the LED. You'll have to source it from someone in Europe (there's a dude in this mailing list who sends them out internationally - someone will tell you his name). Regards, Arun ----- Original message ----- From: "Reno Bunsoy" To: ronja at lists.pointless.net Date: Thu, 22 Nov 2007 07:51:28 -0800 (PST) Subject: [Ronja] RONJA newbie here, please help Sir/Ma'am Good day! My group and I are working on RONJA Tetrapolis. I have noticed that some electronic components are not available in the Philippine market. Those components are enumerated below. 74HC164 74HC4040 74HC93 74HCT14 CM322522 33uH/0.32A/0.25ohm (COIL) 100uH/0.32A/0.6ohm (COIL) 16MHz crystal oscillator DS26LS31 DS26LS32 LM2671M-5.0 5uF/16 SK36 eledis_1A21-NF1PCAE BAT46 BF908 BPW43 NE592 HPWT-BD00-F4000 As for the resistor with 0.6W we've used a 1W resistor. We've tried the equivalent components listed at your site but still we can't find the said components. Are there any other substitute that we can use? If not, the that leaves us in ordering the components at your site. How long do you think will it take us to receive the components? Kindly send us the details on shipping. Thanks and God Bless. All that is gold does not glitter, Not all those who wander are lost; The old that is strong does not wither, Deep roots are not reached by the frost. >From the ashes a fire shall be woken, A light from the shadows shall spring; Renewed shall be blade that was broken, The crownless again shall be king. ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ From clock2 at centrum.cz Sat Nov 24 10:40:06 2007 From: clock2 at centrum.cz (Karel Kulhavy) Date: Sat, 24 Nov 2007 11:40:06 +0100 Subject: [Ronja] RONJA newbie here, please help In-Reply-To: <169948.64327.qm@web52006.mail.re2.yahoo.com> References: <169948.64327.qm@web52006.mail.re2.yahoo.com> Message-ID: <200711241140.13209@centrum.cz> ______________________________________________________________ > Od: renobunsoy na yahoo.com > Komu: ronja na lists.pointless.net > Datum: 22.11.2007 16:51 > P?edm?t: [Ronja] RONJA newbie here, please help > >Sir/Ma'am > >Good day! > >My group and I are working on RONJA Tetrapolis. I have noticed that some >electronic components are not available in the Philippine market. Those >components are enumerated below. >74HC164 >74HC4040 >74HC93 >74HCT14 >CM322522 >33uH/0.32A/0.25ohm (COIL) >100uH/0.32A/0.6ohm (COIL) >16MHz crystal oscillator >DS26LS31 >DS26LS32 >LM2671M-5.0 >5uF/16 >SK36 >eledis_1A21-NF1PCAE >BAT46 >BF908 >BPW43 >NE592 >HPWT-BD00-F4000 > >As for the resistor with 0.6W we've used a 1W resistor. >We've tried the equivalent components listed at your site but still we can't >find the said components. Are there any other substitute that we can use? If >not, the that leaves us in ordering the components at your site. How long do I unfortunately don't sell anything. But try distrelec.com, they claim to be international, and I ordered lot of this stuff from them. They are likely to have all or most of the components. CL< >you think will it take us to receive the components? Kindly send us the details >on shipping. > >Thanks and God Bless. > >All that is gold does not glitter, >Not all those who wander are lost; >The old that is strong does not wither, >Deep roots are not reached by the frost. > >>From the ashes a fire shall be woken, >A light from the shadows shall spring; >Renewed shall be blade that was broken, >The crownless again shall be king. > > > ____________________________________________________________________________________ >Be a better sports nut! Let your teams follow you >with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ >-- >Twibright Ronja mailing list http://ronja.twibright.com >Ronja na lists.pointless.net >http://pointless.net/mailman/listinfo/ronja > > From clock2 at centrum.cz Sat Nov 24 11:00:34 2007 From: clock2 at centrum.cz (Karel Kulhavy) Date: Sat, 24 Nov 2007 12:00:34 +0100 Subject: [Ronja] Comparison video between old and new holder Message-ID: <200711241200.20873@centrum.cz> You can see here a Ronja installation with the noew holder/console takes up less space and is lighter. The old installation weighs 15.6kg and the new 10.6kg: http://ronja.twibright.com/3d/comparison_mpeg4_asp.avi Use mplayer -loop 0 to see it in a loop. CL< From adinov at yahoo.com Fri Nov 30 02:38:27 2007 From: adinov at yahoo.com (alex dinovitser) Date: Thu, 29 Nov 2007 18:38:27 -0800 (PST) Subject: [Ronja] Pyroelectric receiver? Message-ID: <917955.64399.qm@web32714.mail.mud.yahoo.com> I am surprised you are using a photodiade for this application because of the problems with ambient light and the possibility of DC saturation. Why not use a pyroelectric receiver? (which will only be sensitive to the AC signal). With a larger area device, you might be able to get *much* better range!! Alex Dinovitser. ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs From gmaxwell at gmail.com Fri Nov 30 03:28:40 2007 From: gmaxwell at gmail.com (Gregory Maxwell) Date: Thu, 29 Nov 2007 22:28:40 -0500 Subject: [Ronja] Pyroelectric receiver? In-Reply-To: <917955.64399.qm@web32714.mail.mud.yahoo.com> References: <917955.64399.qm@web32714.mail.mud.yahoo.com> Message-ID: On Nov 29, 2007 9:38 PM, alex dinovitser wrote: > I am surprised you are using a photodiade for this application because of the > problems with ambient light and the possibility of DC saturation. Why not use a > pyroelectric receiver? (which will only be sensitive to the AC signal). With a > larger area device, you might be able to get *much* better range!! I can't comment on the Ronja design decisions but I'm puzzled by your suggestion. I've never seen a pyroelectric detector that was very past. Most that I've seen have a bandpass no more than 100kHz or so, while ronja needs a bandpass of many mHz. Perhaps I just haven't been following pytoelectric detector science. Could you suggest a part that you think might better fit ronja than the current PIN diode? From adinov at yahoo.com Fri Nov 30 05:56:26 2007 From: adinov at yahoo.com (alex dinovitser) Date: Thu, 29 Nov 2007 21:56:26 -0800 (PST) Subject: [Ronja] Pyroelectric receiver? In-Reply-To: Message-ID: <838767.76867.qm@web32706.mail.mud.yahoo.com> I also thought these detectors were slow, until a colleague of mine showed me a device (that he'd just blown up with a laser pulse!). There are probably many different manufacturers, probably cheaper than this ($100) laboratory device from "Molectron" Called the "P1-60" with a flat frequency response of 70MHz. The largest version, the P1-65 has an active diameter of 5mm or ~20mm^2, if you need that much! --- Gregory Maxwell wrote: > On Nov 29, 2007 9:38 PM, alex dinovitser wrote: > > I am surprised you are using a photodiade for this application because of > the > > problems with ambient light and the possibility of DC saturation. Why not > use a > > pyroelectric receiver? (which will only be sensitive to the AC signal). > With a > > larger area device, you might be able to get *much* better range!! > > I can't comment on the Ronja design decisions but I'm puzzled by your > suggestion. I've never seen a pyroelectric detector that was very > past. Most that I've seen have a bandpass no more than 100kHz or so, > while ronja needs a bandpass of many mHz. > > Perhaps I just haven't been following pytoelectric detector science. > Could you suggest a part that you think might better fit ronja than > the current PIN diode? > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > ____________________________________________________________________________________ Get easy, one-click access to your favorites. Make Yahoo! your homepage. http://www.yahoo.com/r/hs From arunk at speedpost.net Fri Nov 30 06:03:46 2007 From: arunk at speedpost.net (Arun Krishnan) Date: Fri, 30 Nov 2007 11:33:46 +0530 Subject: [Ronja] Pyroelectric receiver? In-Reply-To: <838767.76867.qm@web32706.mail.mud.yahoo.com> References: <838767.76867.qm@web32706.mail.mud.yahoo.com> Message-ID: <1196402626.15490.1224041373@webmail.messagingengine.com> Hi, $100? A whole RONJA kit costs less than that to make yo. Regards, Arun ----- Original message ----- From: "alex dinovitser" To: "Twibright Ronja" Date: Thu, 29 Nov 2007 21:56:26 -0800 (PST) Subject: Re: [Ronja] Pyroelectric receiver? I also thought these detectors were slow, until a colleague of mine showed me a device (that he'd just blown up with a laser pulse!). There are probably many different manufacturers, probably cheaper than this ($100) laboratory device from "Molectron" Called the "P1-60" with a flat frequency response of 70MHz. The largest version, the P1-65 has an active diameter of 5mm or ~20mm^2, if you need that much! --- Gregory Maxwell wrote: > On Nov 29, 2007 9:38 PM, alex dinovitser wrote: > > I am surprised you are using a photodiade for this application because of > the > > problems with ambient light and the possibility of DC saturation. Why not > use a > > pyroelectric receiver? (which will only be sensitive to the AC signal). > With a > > larger area device, you might be able to get *much* better range!! > > I can't comment on the Ronja design decisions but I'm puzzled by your > suggestion. I've never seen a pyroelectric detector that was very > past. Most that I've seen have a bandpass no more than 100kHz or so, > while ronja needs a bandpass of many mHz. > > Perhaps I just haven't been following pytoelectric detector science. > Could you suggest a part that you think might better fit ronja than > the current PIN diode? > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > ____________________________________________________________________________________ Get easy, one-click access to your favorites. Make Yahoo! your homepage. http://www.yahoo.com/r/hs -- Twibright Ronja mailing list http://ronja.twibright.com Ronja at lists.pointless.net http://pointless.net/mailman/listinfo/ronja From adinov at yahoo.com Fri Nov 30 06:31:48 2007 From: adinov at yahoo.com (alex dinovitser) Date: Thu, 29 Nov 2007 22:31:48 -0800 (PST) Subject: [Ronja] Pyroelectric receiver? In-Reply-To: <1196402626.15490.1224041373@webmail.messagingengine.com> Message-ID: <874948.64866.qm@web32711.mail.mud.yahoo.com> There's no fundamental reason these devices should be so expensive... A lab grade photodiode costs more! A pyroelectric detector from Farnell costs about $10, but is slow.. for PIR alarms etc. Anyhow, here is a datasheet I just downloaded from Coherent scientific... If someone finds a suitable low-cost device out there, please let me know!!! One disadvantage of PIR is that the spectral response is extremely broad. If this causes a problem (although I can't see why?), you may need an optical bandpass filter. Another advantage is that the preamplifier is always built-in to the detector, so you will not need the BF908 circuit. Note that the smaller PIR detectors have a lower "Noise Equivalent Power", and hence may be more suitable for long-range. best regards, and ciao for now..... Alex Dinovitser. --- Arun Krishnan wrote: > Hi, > > $100? A whole RONJA kit costs less than that to make yo. > > Regards, > Arun > > > ----- Original message ----- > From: "alex dinovitser" > To: "Twibright Ronja" > Date: Thu, 29 Nov 2007 21:56:26 -0800 (PST) > Subject: Re: [Ronja] Pyroelectric receiver? > > I also thought these detectors were slow, until a colleague of mine > showed me a > device (that he'd just blown up with a laser pulse!). > > There are probably many different manufacturers, probably cheaper than > this > ($100) laboratory device from "Molectron" > Called the "P1-60" with a flat frequency response of 70MHz. The largest > version, the P1-65 has an active diameter of 5mm or ~20mm^2, if you need > that > much! > > > --- Gregory Maxwell wrote: > > > On Nov 29, 2007 9:38 PM, alex dinovitser wrote: > > > I am surprised you are using a photodiade for this application because of > > the > > > problems with ambient light and the possibility of DC saturation. Why not > > use a > > > pyroelectric receiver? (which will only be sensitive to the AC signal). > > With a > > > larger area device, you might be able to get *much* better range!! > > > > I can't comment on the Ronja design decisions but I'm puzzled by your > > suggestion. I've never seen a pyroelectric detector that was very > > past. Most that I've seen have a bandpass no more than 100kHz or so, > > while ronja needs a bandpass of many mHz. > > > > Perhaps I just haven't been following pytoelectric detector science. > > Could you suggest a part that you think might better fit ronja than > > the current PIN diode? > > > > -- > > Twibright Ronja mailing list http://ronja.twibright.com > > Ronja at lists.pointless.net > > http://pointless.net/mailman/listinfo/ronja > > > > > > > ____________________________________________________________________________________ > Get easy, one-click access to your favorites. > Make Yahoo! your homepage. > http://www.yahoo.com/r/hs > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > ____________________________________________________________________________________ Be a better pen pal. Text or chat with friends inside Yahoo! Mail. See how. http://overview.mail.yahoo.com/ -------------- next part -------------- A non-text attachment was scrubbed... Name: Pyroelectric_71928.pdf Type: application/pdf Size: 555885 bytes Desc: 3724812025-Pyroelectric_71928.pdf Url : http://pointless.net/pipermail/ronja/attachments/20071129/224bd63e/attachment-0001.pdf From gullik.webjorn at flysta.net Fri Nov 30 10:28:58 2007 From: gullik.webjorn at flysta.net (=?iso-8859-1?Q?Gullik_Webj=F6rn?=) Date: Fri, 30 Nov 2007 11:28:58 +0100 Subject: [Ronja] Pyroelectric receiver? In-Reply-To: <874948.64866.qm@web32711.mail.mud.yahoo.com> Message-ID: Hmm, What source of light would you be using? Surely not LEDS, I read the datasheet, and as I understand it that these devices are optimised for 5-15 uM wavelength, i.e. far far infrared, whereas Ronja goes below 1 uM, i.e. to 630 nM. Gullik -----Ursprungligt meddelande----- Fr?n: ronja-bounces+gullik.webjorn=flysta.net at lists.pointless.net [mailto:ronja-bounces+gullik.webjorn=flysta.net at lists.pointless.net]F?r alex dinovitser Skickat: den 30 november 2007 07:32 Till: Twibright Ronja ?mne: Re: [Ronja] Pyroelectric receiver? There's no fundamental reason these devices should be so expensive... A lab grade photodiode costs more! A pyroelectric detector from Farnell costs about $10, but is slow.. for PIR alarms etc. Anyhow, here is a datasheet I just downloaded from Coherent scientific... If someone finds a suitable low-cost device out there, please let me know!!! One disadvantage of PIR is that the spectral response is extremely broad. If this causes a problem (although I can't see why?), you may need an optical bandpass filter. Another advantage is that the preamplifier is always built-in to the detector, so you will not need the BF908 circuit. Note that the smaller PIR detectors have a lower "Noise Equivalent Power", and hence may be more suitable for long-range. best regards, and ciao for now..... Alex Dinovitser. --- Arun Krishnan wrote: > Hi, > > $100? A whole RONJA kit costs less than that to make yo. > > Regards, > Arun > > > ----- Original message ----- > From: "alex dinovitser" > To: "Twibright Ronja" > Date: Thu, 29 Nov 2007 21:56:26 -0800 (PST) > Subject: Re: [Ronja] Pyroelectric receiver? > > I also thought these detectors were slow, until a colleague of mine > showed me a > device (that he'd just blown up with a laser pulse!). > > There are probably many different manufacturers, probably cheaper than > this > ($100) laboratory device from "Molectron" > Called the "P1-60" with a flat frequency response of 70MHz. The largest > version, the P1-65 has an active diameter of 5mm or ~20mm^2, if you need > that > much! > > > --- Gregory Maxwell wrote: > > > On Nov 29, 2007 9:38 PM, alex dinovitser wrote: > > > I am surprised you are using a photodiade for this application because of > > the > > > problems with ambient light and the possibility of DC saturation. Why not > > use a > > > pyroelectric receiver? (which will only be sensitive to the AC signal). > > With a > > > larger area device, you might be able to get *much* better range!! > > > > I can't comment on the Ronja design decisions but I'm puzzled by your > > suggestion. I've never seen a pyroelectric detector that was very > > past. Most that I've seen have a bandpass no more than 100kHz or so, > > while ronja needs a bandpass of many mHz. > > > > Perhaps I just haven't been following pytoelectric detector science. > > Could you suggest a part that you think might better fit ronja than > > the current PIN diode? > > > > -- > > Twibright Ronja mailing list http://ronja.twibright.com > > Ronja at lists.pointless.net > > http://pointless.net/mailman/listinfo/ronja > > > > > > > ____________________________________________________________________________ ________ > Get easy, one-click access to your favorites. > Make Yahoo! your homepage. > http://www.yahoo.com/r/hs > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > ______________________________________________________________________ ______________ Be a better pen pal. Text or chat with friends inside Yahoo! Mail. See how. http://overview.mail.yahoo.com/ From asteri_x at freemail.hu Fri Nov 30 13:39:54 2007 From: asteri_x at freemail.hu (=?UTF-8?B?R3l1cmvDsyBNYXJ0aW4=?=) Date: Fri, 30 Nov 2007 14:39:54 +0100 Subject: [Ronja] detector Message-ID: <475012AA.4070304@freemail.hu> Hey guys! Just found on ebay: http://cgi.ebay.com/Lot-of-5-80MHz-Si-PIN-Photo-Diode-for-Laser-Diode-Sense_W0QQitemZ270191338452QQihZ017QQcategoryZ4660QQcmdZViewItem Anyone already made some experiences with it? Seems to be suitable for 100Mbit receiver. (31.25MHz is much lower than the 80MHz) bye Martin