Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
My original post suggested a possible application which incorporated the use ofa bandpass filter for synthesizing a 60Hz signal for off grid power: "...we discussed inverter design and I suggested a 60Hz square wave with a fourth order band pass filter to capture the fundamental frequency and generate a 60Hz sinusoid." Apparently, someone else is thinkingthe same way. It's nice to know that I'm not totally off the mark with my suggestion. We can argue the merits of what we believe to be the "ideal" circuit all day long.This is (IMO) is a valid alternative. The spirit of my original post hasn't changed and I hope some of you findmy contributionuseful or at least a good read. Mike ___ Standalone Circuit Converts Square Waves To Sine Waves John R. Ambrose ED Online ID #9493January 20, 2005 http://www.elecdesign.com/Articles/Index.cfm?AD=1ArticleID=9493 ___ Kirk McLoren [EMAIL PROTECTED] wrote: Just proof I need to answer email after I sleep. The idea in my mind was you were pumping a squarewave through a lowpass filter to make an approximation of grid power. I see you are just using this as a control signal. Lancaster wrote some articles about approximating a sinewave http://www.tinaja.com/magsn01.asp http://www.tinaja.com/glib/numschip.pdfMichael Redler [EMAIL PROTECTED] wrote: "Very lossy -- and not recommended." OK Soare you going to explain why or just leave me hangin'? MikeKirk McLoren [EMAIL PROTECTED] wrote: Lossy Very lossy -- and not recommended. Don Lancaster was interested in efficient inverters and the least number of switches. I think his website is tiaja.com If not he should be easy to Google -KirkMichael Redler [EMAIL PROTECTED] wrote: I posted this in another group and thought it might also benefit some of you since it's logical to think that some members are off-grid and synthesizing their own power signal. MikeMichael Redler [EMAIL PROTECTED] wrote: Date: Thu, 1 Sep 2005 08:05:16 -0700 (PDT)From: Michael Redler [EMAIL PROTECTED]Subject: OpAmp Active Filter SynthesisTo: [EMAIL PROTECTED] Earlier, we discussed inverter design and I suggested a 60Hz square wave with a fourth order band pass filter to capture the fundamental frequency and generate a 60Hz sinusoid. Although I'm not committed to the square wave synthesis, I do believe that a good filter contributes to clean power, irrespective of your oscillator design. So, I thought this might come in handy: http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html ...my $.02 Mike___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Sheesh Mike why the hostility? It sounds like you don't really want any help. I am sorry if my humor comes off like what do you call it? Hmmm? Please stop trying to be profound and get to the point. You might reread your first post in this thread. You never stated a point to begin with. I have no idea what level of expertise you have. Thus, I speak in generalities. Ask a stupid question get a stupid answer. Brian. ___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Kirk McLoren wrote: Very lossy -- and not recommended. Don Lancaster was interested in efficient inverters and the least number of switches. I think his website is tiaja.com http://www.tinaja.com/magsn01.asp ___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Hi Mike So would I. Did you? The filter has less to do with sine wave synthesis and more to do with ensuring a clean signal. Of course, this is basic electronics. Which is probably why Kirk said it is very lossy. To turn away a signal is in itself loss unless you have some way to feed it back after massaging it. Do you have access to an oscilloscope? Check out the wave shape coming out of a cheap battery backup used for small computers. Compare it to the wave shape of grid AC. Can you see the difference? There is also the added bonus of creating/using more primitive signal generators without sacrificing quality since the filter will reject unwanted signals. Why are you using primitive electronics? OK Soare you going to explain why or just leave me hangin'? Mike You haven't the foggiest idea why I said you were hanging? Hmmm. I am trying to help. Brian ___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Brian Rodgers [EMAIL PROTECTED] wrote: Hi Mike"So would I."Did you?"The filter has less to do with sine wave synthesis and more to dowith ensuring a clean signal."Of course, this is basic electronics. Then why did your original message question my methodfor generating the signal when I didn't offer one. I made a suggestion to use a filter to cleanthe signal? Which is probably why Kirk said it is very lossy. What losses? A Sallen-Key, Op-amp (voltage controlled device - impedance is infinite) circuit,operating at5volts (for example) will attenuatethe pass band by a very small amount (milliamps). I can only assume that Kirk thought I was suggesting to filter the amplified, power signal. To turn away a signal is in itself loss Agreed. Quantify that loss, compare it to losses used in other circuits and get back to me with an answer as to how important that loss is. unless you have some way to feed it backafter massaging it. Do you have access to an oscilloscope?Check out the wave shape coming out of a cheap battery backup used forsmall computers. Compare it to the wave shape of grid AC.Can you see the difference? "There is also the added bonus of creating/using more primitive signal generators without sacrificing quality since the filter willreject unwanted signals." Why are you using primitive electronics? Cheap, easy to build, parts are readily available,lends itself to analog designs without requiring a lot of tuning and NO programming. But, it was never my intention to debate the "ideal" circuit design with you in the first place. "OK Soare you going to explain why or just leave me hangin'? Mike"You haven't the foggiest idea why I said you were hanging?No. I still don't. Hmmm.Hmmm? Please stop trying to be profound and get to the point. I am trying to help. So am I. I simply offered information. Without presuming it's value to others, I offered it as-is, for people to useor not use. Do you think this group would be as successful as it is if people didn't have a desire to experiment, depart from what everyone else is doingand take a shot at being innovative? Your suggestion to copy and/or scavenge from other devices is important. However, if that's all you do and reject unconventional approaches because they are too time consuming or more expensive or simply because "it's not done that way", then I don't have much more to say to you on this topic. This isn't the first time and it won't be the last time I suggest something that is summarily rejected or otherwise called impractical, too...(whatever), or not what everyone else is doing. There are days when I actually see it as a compliment. So, Thanks! Brian Mike___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Just proof I need to answer email after I sleep. The idea in my mind was you were pumping a squarewave through a lowpass filter to make an approximation of grid power. I see you are just using this as a control signal. Lancaster wrote some articles about approximating a sinewave http://www.tinaja.com/magsn01.asp http://www.tinaja.com/glib/numschip.pdfMichael Redler [EMAIL PROTECTED] wrote: "Very lossy -- and not recommended." OK Soare you going to explain why or just leave me hangin'? MikeKirk McLoren [EMAIL PROTECTED] wrote: Lossy Very lossy -- and not recommended. Don Lancaster was interested in efficient inverters and the least number of switches. I think his website is tiaja.com If not he should be easy to Google -KirkMichael Redler [EMAIL PROTECTED] wrote: I posted this in another group and thought it might also benefit some of you since it's logical to think that some members are off-grid and synthesizing their own power signal. MikeMichael Redler [EMAIL PROTECTED] wrote: Date: Thu, 1 Sep 2005 08:05:16 -0700 (PDT)From: Michael Redler [EMAIL PROTECTED]Subject: OpAmp Active Filter SynthesisTo: [EMAIL PROTECTED] Earlier, we discussed inverter design and I suggested a 60Hz square wave with a fourth order band pass filter to capture the fundamental frequency and generate a 60Hz sinusoid. Although I'm not committed to the square wave synthesis, I do believe that a good filter contributes to clean power, irrespective of your oscillator design. So, I thought this might come in handy: http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html ...my $.02 Mike Start your day with Yahoo! - make it your home page ___Biofuel mailing listBiofuel@sustainablelists.orghttp://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.orgBiofuel at Journey to Forever:http://journeytoforever.org/biofuel.htmlSearch the combined Biofuel and Biofuels-biz list archives (50,000 messages):http://www.mail-archive.com/biofuel@sustainablelists.org/___Biofuel mailing listBiofuel@sustainablelists.orghttp://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.orgBiofuel at Journey to Forever:http://journeytoforever.org/biofuel.htmlSearch the combined Biofuel and Biofuels-biz list archives (50,000 messages):http://www.mail-archive.com/biofuel@sustainablelists.org/ Yahoo! Mail for Mobile Take Yahoo! Mail with you! Check email on your mobile phone.___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Lossy Very lossy -- and not recommended. Don Lancaster was interested in efficient inverters and the least number of switches. I think his website is tiaja.com If not he should be easy to Google -KirkMichael Redler [EMAIL PROTECTED] wrote: I posted this in another group and thought it might also benefit some of you since it's logical to think that some members are off-grid and synthesizing their own power signal. MikeMichael Redler [EMAIL PROTECTED] wrote: Date: Thu, 1 Sep 2005 08:05:16 -0700 (PDT)From: Michael Redler [EMAIL PROTECTED]Subject: OpAmp Active Filter SynthesisTo: [EMAIL PROTECTED] Earlier, we discussed inverter design and I suggested a 60Hz square wave with a fourth order band pass filter to capture the fundamental frequency and generate a 60Hz sinusoid. Although I'm not committed to the square wave synthesis, I do believe that a good filter contributes to clean power, irrespective of your oscillator design. So, I thought this might come in handy: http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html ...my $.02 Mike Start your day with Yahoo! - make it your home page ___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
"Very lossy -- and not recommended." OK Soare you going to explain why or just leave me hangin'? MikeKirk McLoren [EMAIL PROTECTED] wrote: Lossy Very lossy -- and not recommended. Don Lancaster was interested in efficient inverters and the least number of switches. I think his website is tiaja.com If not he should be easy to Google -KirkMichael Redler [EMAIL PROTECTED] wrote: I posted this in another group and thought it might also benefit some of you since it's logical to think that some members are off-grid and synthesizing their own power signal. MikeMichael Redler [EMAIL PROTECTED] wrote: Date: Thu, 1 Sep 2005 08:05:16 -0700 (PDT)From: Michael Redler [EMAIL PROTECTED]Subject: OpAmp Active Filter SynthesisTo: [EMAIL PROTECTED] Earlier, we discussed inverter design and I suggested a 60Hz square wave with a fourth order band pass filter to capture the fundamental frequency and generate a 60Hz sinusoid. Although I'm not committed to the square wave synthesis, I do believe that a good filter contributes to clean power, irrespective of your oscillator design. So, I thought this might come in handy: http://www.analog.com/Analog_Root/static/techSupport/designTools/interactiveTools/filter/filter.html ...my $.02 Mike Start your day with Yahoo! - make it your home page ___Biofuel mailing listBiofuel@sustainablelists.orghttp://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.orgBiofuel at Journey to Forever:http://journeytoforever.org/biofuel.htmlSearch the combined Biofuel and Biofuels-biz list archives (50,000 messages):http://www.mail-archive.com/biofuel@sustainablelists.org/___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Hi I have a bit of electronic knowledge albeit a tad rusty. I followed your link but without knowing what you are trying to do I am at a loss as well. What are you inverting? Are you simply changing DC to AC? If I was trying to do this the first thing I would do is hit the standard circuit design books. That was back in the day when we relied on books, hehe I just googled dc ac inverter circuit design and found all sorts of stuff. Take a look at this for example: http://repairfaq.ece.drexel.edu/sam/samschem.htm#schiin The next thing I would do is look at a modern UPS and see how the pros are inverting DC to AC. Or just take the circuit out of an old working battery backup and recycle it. Ups often have dead batteries but still invert DC to AC. I hope it gets you off the edge you were hangin on. Brian Rodgers ___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
Re: [Biofuel] Cross Posted: OpAmp Active Filter Synthesis
Brian, "Are you simply changing DC to AC?" Yes. "If I was trying to do this the first thing I would do is hit the standard circuit design books." So would I. The filter has less to do with sine wave synthesis and more to do with ensuring a clean signal. There is also the added bonus of creating/usingmore primitivesignal generators without sacrificing qualitysince the filter will reject unwantedsignals. "The next thing I would do is look at a modern UPS and see how the pros are inverting DC to AC. Or just take the circuit out of an old working battery backup and recycle it." Yep. I'm still with you Brian. "I hope it gets you off the edge you were hangin on." I haven't the foggiest notion what you mean by that. MikeBrian Rodgers [EMAIL PROTECTED] wrote: Hi I have a bit of electronic knowledge albeit a tad rusty.I followed your link but without knowing what you are trying to do Iam at a loss as well.What are you inverting?Are you simply changing DC to AC?If I was trying to do this the first thing I would do is hit thestandard circuit design books.That was back in the day when we relied on books, hehe I just googleddc ac inverter circuit design and found all sorts of stuff. Take alook at this for example:http://repairfaq.ece.drexel.edu/sam/samschem.htm#schiinThe next thing I would do is look at a modern UPS and see how the prosare inverting DC to AC. Or just take the circuit out of an old workingbattery backup and recycle it. Ups often have dead batteries but stillinvert DC to AC.I hope it gets you off the edge you were hangin on.Brian Rodgers___ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
