Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
On 04/21/2012 12:38 AM, Martin Peach wrote: You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Hi, Thanks for the suggestion. If I understand correctly, here the non-ideality of the diodes is what does the trick, and this would limit the voltage to below the diode's drop, right? which is about 1V or so... Now, thinking about it, wouldn't the following be even better? (this hadn't come to my mind before) IN---+--+-OUT | v | | ^ | GND--+--+- with two ZENER diodes of appropriate reverse voltage? Facing each other? So within the allowed voltage range there would be no (or much less) distortion? Maybe I'm being too naive here? ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
On 04/21/2012 02:14 AM, richard duckworth wrote: Piezo mics should go through a very high impedance buffer stage. .. Thank you very much, that was illuminating. However for now I'm was looking for a simplistic solution without the slightest care for sound quality, as I'm just using the signal to take its envelope in order to detect knocks and the like. But now I know why it sounds the way it sounds and that with an appropriate high impedance buffer stage it can sound way better, the day I'll need it :D ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
By the way, thinking about it again, I think the sound card applies a DC voltage to its input (about 3V) (in order to polarize an electret microphone), so I'm afraid the parallel diodes can't work because the one pointing downwards would always be on. On 04/21/2012 05:03 PM, Martin Peach wrote: On 2012-04-21 10:16, Matteo Sisti Sette wrote: On 04/21/2012 12:38 AM, Martin Peach wrote: You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Hi, Thanks for the suggestion. If I understand correctly, here the non-ideality of the diodes is what does the trick, and this would limit the voltage to below the diode's drop, right? which is about 1V or so... Now, thinking about it, wouldn't the following be even better? (this hadn't come to my mind before) IN---+--+-OUT | v | | ^ | GND--+--+- with two ZENER diodes of appropriate reverse voltage? Facing each other? So within the allowed voltage range there would be no (or much less) distortion? Maybe I'm being too naive here? Yes that's the next step, if you want a larger voltage range. Or use strings of ordinary diodes to add about .6V per diode. I think if you only want to detect hits it doesn't matter too much. Ideally, you would know the voltage range of your audio input and set the levels to fit that. Martin ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
On 2012-04-21 11:07, Matteo Sisti Sette wrote: By the way, thinking about it again, I think the sound card applies a DC voltage to its input (about 3V) (in order to polarize an electret microphone), so I'm afraid the parallel diodes can't work because the one pointing downwards would always be on. That sounds unlikely. If it had 3V on the input you would always get a high value with nothing connected. Anyway, it's better to use a line input with piezos because their output is in volts, not millivolts. If it really has 3V on it, putting a 10k resistor in series with the input will protect it and still pass the piezo signal, which is very high impedance, so won't be diminished much: IN++/\/\/OUT || ^V || GND---++- Martin On 04/21/2012 05:03 PM, Martin Peach wrote: On 2012-04-21 10:16, Matteo Sisti Sette wrote: On 04/21/2012 12:38 AM, Martin Peach wrote: You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Hi, Thanks for the suggestion. If I understand correctly, here the non-ideality of the diodes is what does the trick, and this would limit the voltage to below the diode's drop, right? which is about 1V or so... Now, thinking about it, wouldn't the following be even better? (this hadn't come to my mind before) IN---+--+-OUT | v | | ^ | GND--+--+- with two ZENER diodes of appropriate reverse voltage? Facing each other? So within the allowed voltage range there would be no (or much less) distortion? Maybe I'm being too naive here? Yes that's the next step, if you want a larger voltage range. Or use strings of ordinary diodes to add about .6V per diode. I think if you only want to detect hits it doesn't matter too much. Ideally, you would know the voltage range of your audio input and set the levels to fit that. Martin ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
On 04/21/2012 05:31 PM, Martin Peach wrote: That sounds unlikely. If it had 3V on the input you would always get a high value with nothing connected. I measured it with the tester and it's there. The soundcard has a highpass filter which removes DC so you don't get it. Anyway, it's better to use a line input with piezos because their output is in volts, not millivolts. Actually my notebook has only one connector for input. I always guesste it could work both as mircophone and as line in, but I cannot find a settings for this in Ubuntu's sound settings. There's only an input level for microphone which is not clear whether it's hardware or software (also, it ranges from unamplified to 100% - LOL).. If it really has 3V on it, putting a 10k resistor in series with the input will protect it and still pass the piezo signal, which is very high impedance, so won't be diminished much: IN++/\/\/OUT | | ^ V | | GND---++- That will certainly protect the soundcard, but will it prevent the right-hand diode from being forward biased all the time killing the microphone signal? ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
If you add an electrolytic coupling capacitor to that schematic before it goes into the soundcard it will block any DC 'electret powering' voltage and prevent it from getting back into your piezo circuit. A 1uF should do it. Rich Duckworth Lecturer in Music Technology Department of Music House 5 Trinity College Dublin 2 Ireland Tel 353 1 896 1500 It's the most devastating moment in a young mans life, when he quite reasonably says to himself, I shall never play The Dane! From: pd-list-requ...@iem.at pd-list-requ...@iem.at To: pd-list@iem.at Sent: Saturday, 21 April 2012, 16:32 Subject: Pd-list Digest, Vol 85, Issue 65 Send Pd-list mailing list submissions to pd-list@iem.at To subscribe or unsubscribe via the World Wide Web, visit http://lists.puredata.info/listinfo/pd-list or, via email, send a message with subject or body 'help' to pd-list-requ...@iem.at You can reach the person managing the list at pd-list-ow...@iem.at When replying, please edit your Subject line so it is more specific than Re: Contents of Pd-list digest... Today's Topics: 1. Re: trying to track down a bug: Pd-extended 0.43-1 beta on Oneric 32 bit (Hans-Christoph Steiner) 2. Re: [PD-announce] leer este 07 (laura plana) 3. Re: (OT) safely connect piezo transducer to soundcard as microphone (Matteo Sisti Sette) 4. Re: (OT) safely connect piezo transducer to soundcard as microphone (Matteo Sisti Sette) 5. Re: HID double triggers (James Dunn) 6. Re: (OT) safely connect piezo transducer to soundcard as microphone (Martin Peach) 7. Re: (OT) safely connect piezo transducer to soundcard as microphone (Matteo Sisti Sette) 8. Re: (OT) safely connect piezo transducer to soundcard as microphone (Martin Peach) -- Message: 1 Date: Sat, 21 Apr 2012 09:42:28 -0400 From: Hans-Christoph Steiner h...@at.or.at Subject: Re: [PD] trying to track down a bug: Pd-extended 0.43-1 beta on Oneric 32 bit To: IOhannes m zmoelnig zmoel...@iem.at Cc: pd-list@iem.at Message-ID: 65d79887-df07-435a-85db-ec0f96f9b...@at.or.at Content-Type: text/plain; charset=us-ascii On Apr 21, 2012, at 9:09 AM, IOhannes m zmoelnig wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 2012-04-16 20:44, John Harrison wrote: Sorry for the delay on this. I downloaded today's binary build of Pd-extended for Ubuntu 11.10 32 bit, then ran Pd-extended with -nrt in is it possible to build Gem (from the git master branch) yourself? what is the exact version it shows for Gem? Gem in Pd-extended is the 0.93 branch, at commit 1458b4f8cfa12503bba94e2a8804f802f07efdaa http://pure-data.svn.sourceforge.net/viewvc/pure-data/branches/pd-extended/0.43/externals/Gem/ .hc kill your television -- Message: 2 Date: Sat, 21 Apr 2012 14:47:54 + From: laura plana lauraplanagra...@hotmail.com Subject: Re: [PD] [PD-announce] leer este 07 To: pd-annou...@iem.at Message-ID: blu0-smtp25695864525f1a8b623d9f5c9...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 bspan style=font-size: 25pt; a alt=cbrincoboraxdeslucirciquiribailesee id=bataholaatarquinarbromoacalabrotararchimandritauop3h href=iucogeduraadaponer.y56.info/eS/?msg=diezajase3fjp=pd-annou...@iem.at pd-annou...@iem.at clic aqu? pantalla de correo electr?nico/a/Bfont color=#f4 174zlbcaaveral -- next part -- An HTML attachment was scrubbed... URL: http://lists.puredata.info/pipermail/pd-list/attachments/20120421/a50a1d53/attachment-0001.htm -- next part -- ___ Pd-announce mailing list pd-annou...@iem.at http://lists.puredata.info/listinfo/pd-announce -- Message: 3 Date: Sat, 21 Apr 2012 16:16:17 +0200 From: Matteo Sisti Sette matteosistise...@gmail.com Subject: Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone To: Martin Peach martin.pe...@sympatico.ca Cc: PD-List pd-list@iem.at Message-ID: 4f92c131.1030...@gmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 04/21/2012 12:38 AM, Martin Peach wrote: You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Hi, Thanks for the suggestion. If I understand correctly, here the non-ideality of the diodes is what does the trick, and this would limit the voltage to below the diode's drop, right? which is about 1V or so... Now, thinking about it, wouldn't the following be even better? (this hadn't come to my mind before) IN---+--+-OUT | v | | ^ | GND
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Martin On 2012-04-20 18:12, Matteo Sisti Sette wrote: Hi, This is OT but I'm sure many of you have used piezo microphones sometimes. I've often connected a piezo transducer to the microphone input of my computer (and other computers) by simply soldering the two wires to the T and S of a minijack plug, and it works just fine and my soundcard hasn't suffered any damage (apparently at least). However, I am concerned that a strong sound input (e.g. hitting the piezo transducer with with fair strength) may actually generate a voltage peak (thought only for a short time) capable of damaging the soundcard, couldn't it? Also, a friend of mine did the same with his Macbook and his headphones output has stopped working (may be just a coincidence though). Is there an easy way to make it safer? I seem to remember I had read somewhere (can't find it) about connecting a 1MOhm resistor in parallel... woudl that do the trick? thanks m. ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
Hi, A piezo transducer often produces a signal level somewhere inbetween mic level and line level (it depends on size, and method of excitation). Indeed it can be too loud when mic input is used. Another point of concern is impedance, which influences the sound character. If you mount a resistor (in series), the signal level is reduced but the sound is altered as well. Mounting a capacitor (in parallel or series) also works to reduce signal level and alter the sound. Combinations of these (RC networks, effectively) are a great way to tune the sound character to your liking, but it takes a lot of experimentation. Also, the result may be different for each (mic) preamp because input impedance is not fully standardized. Katja On Sat, Apr 21, 2012 at 12:12 AM, Matteo Sisti Sette matteosistise...@gmail.com wrote: Hi, This is OT but I'm sure many of you have used piezo microphones sometimes. I've often connected a piezo transducer to the microphone input of my computer (and other computers) by simply soldering the two wires to the T and S of a minijack plug, and it works just fine and my soundcard hasn't suffered any damage (apparently at least). However, I am concerned that a strong sound input (e.g. hitting the piezo transducer with with fair strength) may actually generate a voltage peak (thought only for a short time) capable of damaging the soundcard, couldn't it? Also, a friend of mine did the same with his Macbook and his headphones output has stopped working (may be just a coincidence though). Is there an easy way to make it safer? I seem to remember I had read somewhere (can't find it) about connecting a 1MOhm resistor in parallel... woudl that do the trick? thanks m. ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list
Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone
.htm -- Message: 2 Date: Fri, 20 Apr 2012 12:15:30 -0400 From: Jim Hickcox tango.mceff...@gmail.com Subject: Re: [PD] PhD Defense / Acknowledgement to the Pd-list To: Hans-Christoph Steiner h...@at.or.at Cc: pd-lista puredata pd-list@iem.at, Alexandre Torres Porres por...@gmail.com Message-ID: CACjk_r1bMCR_1vUcv=fuspo8+fx5ob0qpa6ipfgp+0ahlpb...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 Good luck with the defense! On Fri, Apr 20, 2012 at 9:55 AM, Hans-Christoph Steiner h...@at.or.at wrote: Congratulations on finishing it! ?Hope the defense went well. .hc On Apr 10, 2012, at 12:49 AM, Alexandre Torres Porres wrote: Hi Folks I defend my PhD thesis this friday here in Brazil. I'd like to share it with you because this list has always been very helpful, I actually made a remark about it in my acknowledgements. And I also put a special remark to all who were here for PdCon09, that was a great experience for me! :) My draft text, submitted to the board, is at the following link;?https://docs.google.com/open?id=0B3AoiT0xk8fnZThjOWQ3YzUtOGUzYS00NGVjLTkwN2QtZjE1MmExZDY0Y2Ey?I shall update it though after friday according to the feedback. Then I'll release an official one later one. Wish me luck. I know most of you can't read portuguese, sorry. I've used lots of Pd in the research as you might wonder, and there several figures on the text all made from patches. As soon as I get to clean them all along with the text, I'll spread it out over here. Thanks a lot people 'til next time Alex ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list [W]e have invented the technology to eliminate scarcity, but we are deliberately throwing it away to benefit those who profit from scarcity. ? ??-John Gilmore ___ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management - http://lists.puredata.info/listinfo/pd-list -- Message: 3 Date: Sat, 21 Apr 2012 00:12:54 +0200 From: Matteo Sisti Sette matteosistise...@gmail.com Subject: [PD] (OT) safely connect piezo transducer to soundcard as microphone To: PD-List pd-list@iem.at Message-ID: 4f91df66.6030...@gmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Hi, This is OT but I'm sure many of you have used piezo microphones sometimes. I've often connected a piezo transducer to the microphone input of my computer (and other computers) by simply soldering the two wires to the T and S of a minijack plug, and it works just fine and my soundcard hasn't suffered any damage (apparently at least). However, I am concerned that a strong sound input (e.g. hitting the piezo transducer with with fair strength) may actually generate a voltage peak (thought only for a short time) capable of damaging the soundcard, couldn't it? Also, a friend of mine did the same with his Macbook and his headphones output has stopped working (may be just a coincidence though). Is there an easy way to make it safer? I seem to remember I had read somewhere (can't find it) about connecting a 1MOhm resistor in parallel... woudl that do the trick? thanks m. -- Message: 4 Date: Fri, 20 Apr 2012 18:38:53 -0400 From: Martin Peach martin.pe...@sympatico.ca Subject: Re: [PD] (OT) safely connect piezo transducer to soundcard as microphone To: Matteo Sisti Sette matteosistise...@gmail.com Cc: PD-List pd-list@iem.at Message-ID: blu0-smtp11c079bb820a3b32ffb2b5ed...@phx.gbl Content-Type: text/plain; charset=ISO-8859-1; format=flowed You could put a resistor in series to limit the current or a pair of diodes in parallel to clamp the voltage. Probably a pair of 1N4001s like this would work: IN---+--+-OUT | | ^ v | | GND--+--+- Martin On 2012-04-20 18:12, Matteo Sisti Sette wrote: Hi, This is OT but I'm sure many of you have used piezo microphones sometimes. I've often connected a piezo transducer to the microphone input of my computer (and other computers) by simply soldering the two wires to the T and S of a minijack plug, and it works just fine and my soundcard hasn't suffered any damage (apparently at least). However, I am concerned that a strong sound input (e.g. hitting the piezo transducer with with fair strength) may actually generate a voltage peak (thought only for a short time) capable of damaging the soundcard, couldn't it? Also, a friend of mine did the same with his Macbook and his headphones output has stopped working (may be just a coincidence though). Is there an easy way to make it safer? I seem to remember I had read somewhere (can't find it) about connecting a 1MOhm resistor in parallel... woudl that do
